Sterling Oxygen Equipment SCW Series User Manual
Operation and Installation Manual  
SCW Series  
Central Chilling Stations  
Important! Read Carefully Before Attempting to Install or Operate Equipment  
Part No. A0551795  
Bulletin No. SC3-635.1  
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Safety Considerations  
Sterling SCW Series central chilling stations are designed to  
provide safe and reliable operation when installed and operated  
within design specifications, following national and local safety  
codes.  
To avoid possible personnel injury or equipment damage when  
installing, operating, or maintaining this equipment, use good  
judgment and follow these safe practices:  
; Only PROPERLY TRAINED personnel familiar with the  
information within this manual should work on this equipment.  
; Follow all local SAFETY CODES.  
; Wear SAFETY GLASSES and WORK GLOVES.  
; Disconnect and/or lock out power before servicing or  
maintaining the chiller.  
; Use care when LOADING, UNLOADING, RIGGING, or  
MOVING this equipment.  
; Operate this equipment within design specifications.  
; OPEN, TAG, and LOCK ALL DISCONNECTS before  
working on equipment. Sterling recommends following OSHA  
Lock-Out/Tag-Out Standard 29 CFR 1910.147.  
; Make sure the unit is properly GROUNDED before switching  
power on.  
; When welding or brazing in or around this equipment, be sure  
VENTILATION is ADEQUATE. PROTECT adjacent  
materials from flame or sparks by shielding with sheet metal.  
An approved FIRE EXTINGUISHER should be close at hand  
and ready for use if needed.  
; Do not jump or bypass any electrical safety control.  
; Do not restore power until all tools, test equipment, chiller and  
related equipment have been removed.  
SCW Series Central Chilling Stations  
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Table of Contents  
1 General Information .................................................8  
; 1-1  
; 1-2  
; 1-3  
; 1-4  
; 1-5  
Introduction .......  
8
Necessary Documents  
Models Covered  
8
9
Standard Features  
Available Options  
9
10  
2 Shipping Information .............................................16  
; 2-1  
; 2-2  
; 2-3  
; 2-4  
; 2-5  
; 2-6  
Unpacking and Inspection  
16  
In the Event of Shipping Damages 16  
If the Shipment is Not Complete  
If the Shipment is Not Correct  
Returns..............  
17  
17  
17  
18  
Uncrating Your New Chiller  
3 Installation...............................................................20  
; 3-1  
; 3-2  
; 3-3  
; 3-4  
; 3-5  
; 3-6  
; 3-7  
; 3-8  
; 3-9  
Installation Location Considerations  
20  
20  
22  
22  
23  
24  
24  
24  
24  
25  
26  
Making Electrical Connections  
Piping Considerations  
Making Process Water Connections  
Making Tank Piping Connections  
Water Connection Sizing Considerations  
Galvanic Corrosion Considerations  
Water Treatment Considerations  
Making Water-Cooled Condenser Connections  
; 3-10 Installing the Remote Air-Cooled Condenser  
; 3-11 Checking Motor Direction  
4 Sequence Of Operation........................................277  
; 4-1  
; 4-2  
; 4-3  
; 4-4  
; 4-5  
Staging..............  
28  
28  
28  
28  
29  
Alarms...............  
Lead-Lag Compressors  
Lead-Lag Pumps  
Chilled Water Circuit  
Page 4 of 77  
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; 4-6  
; 4-7  
; 4-8  
; 4-9  
Refrigeration Circuit  
Freezestat Control  
High Pressure Cutout  
Low Pressure Cutout  
29  
29  
31  
31  
31  
32  
32  
32  
; 4-10 Flow Switch.......  
; 4-11 Control Nipple ...  
; 4-12 Control Probe....  
; 4-13 Chilled Water Manifold  
; 4-14 Optional Condenser Water Manifold 32  
5 Startup Checklists..................................................34  
; 5-1  
; 5-2  
; 5-3  
; 5-4  
; 5-5  
; 5-6  
; 5-7  
Introduction .......  
34  
34  
36  
Water-Cooled SCW Series Startup Checklist  
Water-Cooled SCW Series Startup  
Remote Air-Cooled SCW Series Startup Checklist 37  
Remote Air-Cooled SCW Series Startup  
Determining Flow Rate  
39  
40  
40  
Shutdown ..........  
6 Graphic Panel Devices...........................................41  
; 6-1  
Indicator Lights and Control Switches (MMI)  
41  
7 Using the Standard Touchscreen Interface .........43  
; 7-1  
; 7-2  
; 7-3  
; 7-4  
; 7-5  
; 7-6  
; 7-7  
Operator Interface Introduction (MMI)  
43  
Using the SCW Series Standard Operator Interface  
44  
Getting Started on the SCW Series Standard Operator Interface 45  
Viewing and Operating Chiller Compressors  
Viewing and Operating Chiller Pumps  
45  
45  
46  
46  
Viewing Active Alarms and Handling Alarm Conditions  
Viewing and Setting System Temperatures  
8 Using the Advanced Touchscreen Interface........48  
; 8-1  
; 8-2  
; 8-3  
; 8-4  
Touchscreen Interface Introduction (MMI)  
48  
Using the SCW Series Advanced Touchscreen Interface  
49  
Getting Started on the SCW Series Advanced Touchscreen Interface 50  
Viewing and Operating Chiller Compressors  
50  
SCW Series Central Chilling Stations  
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8-5 Viewing and Operating Chiller Pumps .................55  
; 8-6  
Viewing Active Alarms and Handling Alarm Conditions  
59  
; 8-7  
Viewing and Setting System Temperatures  
61  
9 Routine Maintenance .............................................64  
; 9-1  
; 9-2  
; 9-3  
; 9-4  
Lubrication.........  
64  
64  
65  
65  
Condenser Maintenance  
Evaporator Maintenance  
Pump Motor Seal  
9-5 Makeup Valve..........................................................65  
; 9-6  
Recommended Pump Tank Spare Parts  
65  
; 9-7  
Preventive Maintenance Service  
66  
10 Troubleshooting .....................................................68  
I Index ........................................................................72  
Page 6 of 77  
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Charts and Figures  
1
2
3
4
5
6
7
8
Typical Two-Circuit 60-195 Ton Water Cooled Chiller  
11  
13  
29  
39  
40  
44  
58  
59  
61  
62  
64  
65  
66  
68  
69  
71  
72  
Typical Two-Circuit 60-195 Ton Remote Air Cooled Chiller  
Freezing Protection Curve  
SCW Series Standard Control Panel  
SCW Series Advanced Control Panel  
SCW Series Standard Control Panel  
SCW Series Advanced Control Panel  
Main Menu Screen (Advanced Control Panel)  
9
Chiller Status Screen (Advanced Control Panel)  
10  
11  
12  
13  
14  
15  
16  
17  
Chiller Configuration Screen (Advanced Control Panel)  
Compressor Run Time Display Screen (Advanced Control Panel)  
Pump Status Screen  
Pump Enables Screen  
Pump Run Time Display Screen  
Alarm Condition Screen  
System Status Screen  
Temperature Input Display Screen  
SCW Series Central Chilling Stations  
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1
General Information  
1-1 Introduction  
Sterling SCW Series central water chilling stations are available in  
water-cooled and remote air-cooled designs. They differ only in  
the condensing media used. The SCW Series units are configured  
with two independent circuits using multiple compressors for each  
circuit. This manual lists information for these units.  
SCW Series chilling stations may be configured with stainless steel  
pump tanks for use as reservoirs for chilled water processes. These  
dual-well models hold hot and cold water before and after it is  
pumped through the chiller. Tanks have recirculation pump(s) to  
send return water to the chiller and process pump(s) to pump  
cooled water directly to process. Standby pumps may be utilized to  
distribute pump service or to allow uninterrupted chiller operation  
during pump maintenance.  
Properly installed, operated, and maintained SCW Series chilling  
stations provide many years of reliable operation. To get the most  
satisfaction from your new chiller, read and follow the  
instructions in this manual.  
1-2 Necessary Documents  
The following documents are necessary for the operation,  
installation, and maintenance of Sterling SCW Series central  
chillers. Additional copies are available from Sterling.  
Familiarize the appropriate personnel with these documents:  
; This manual.  
; The schematic and connection diagram in the control  
enclosure.  
; Operation and installation manuals for accessories and options  
selected by the customer.  
; The Customer Parts List included in the information packet.  
Page 8 of 77  
SCW Series Central Chilling Stations  
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1-3 Models Covered  
This manual provides operation, installation, and maintenance  
instructions for the SCW Series central chilling stations.  
Model numbers are listed on the serial tag. A model number  
followed by Q indicates a specially constructed unit, and not all  
information in this manual may apply. Make sure that you know  
the model number, serial number, and operating voltage of your  
chiller if you contact Sterling.  
1-4 Standard Features  
•
Two independent refrigeration circuits  
•
•
High-efficiency screw compressors  
Stainless steel brazed plate (60 & 75) Shell & Tube (90 –  
195) evaporators  
•
•
•
Cleanable shell and tube condensers (water-cooled models)  
Electronic expansion valve  
2 remote single circuit condensers with variable speed lead  
fans and fan cycling (air-cooled models)  
•
•
NEMA 12 electrical enclosure  
Mitsubishi FX2N PLC control with F930GOT touchscreen  
interface.  
•
•
•
High and low refrigerant pressure safeties  
Touch-safe branch circuit fusing  
Evaporator water piping manifold (Condenser manifold  
optional)  
•
•
•
•
•
•
R-134a refrigerant  
Digital low temperature freezestat  
Liquid line solenoid and shut-off valves  
Chilled water flow switches  
1 year warranty on parts and labor  
3 year warranty on controller  
SCW Series Central Chilling Stations  
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1-5 Available Options  
SCW Series central chillers are available with options to tailor the  
unit to your requirements. Some are factory installed; some can be  
retro-fitted in the field. Consult Sterling sales for more  
information. Available SCW Series options include:  
• Advanced control package including: Mitsubishi P2A PLC  
control with A970GOT – color touchscreen interface; provides  
control of up to nine additional chillers, cooling tower system,  
water treatment system  
• General Fault audible/visual alarm with elevated light stack  
• Non-fused rotary thru-the-door disconnect switches  
• Electrical operation available in 208, 460, and 575 volts,  
60 Hz; 200, 380, and 415 volts, 50 Hz  
• UL/CUL-listed electrical subpanel  
• Water cooled condenser manifold  
• Onsite startup  
Standard Features on Remote Condensers  
• Direct-drive 3-phase fan motors with ball bearings and internal  
overload protection  
• Electronic variable-speed control of lead fan and fan cycling  
for constant condenser head pressure control  
• Fans are 30” (76 cm) in diameter and have PVC-coated steel  
fan guards; 1½ hp (1.12 kW) variable-speed fans are 26” (66  
cm) in diameter  
• Internal baffles between fan cells  
• UL listed in the United States and Canada  
• Patented floating tube coil to eliminate tube sheet leaks  
• Copper tube condenser coils have corrugated aluminum fins  
• Weather-proof control panel with factory-mounted door  
interrupt switch  
• High-efficiency condenser coil, designed for optimum  
performance  
• Aluminum housing provides corrosion protection for outdoor  
applications  
Page 10 of 77  
SCW Series Central Chilling Stations  
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Model Number Nomeclature  
SCW  
W
060  
SCW – Screw Compressor Central Chiller  
Condenser Type  
R – Remote Air Cooled  
W – Water Cooled  
(Nominal Unit Size)  
060  
075  
090  
100  
115  
145  
165  
195  
SCW Series Central Chilling Stations  
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Figure 1  
Typical Two-Circuit 60-195 Ton Water Cooled Chiller  
SCWW-xxx  
Model  
60  
75  
90  
100  
Cooling Capacity (tons) @ 50°F LWTc  
Capacity stages  
60.4  
74.9  
Infinite Unloading  
88.8  
102.2  
EER (BTUH/W)  
15.2  
145  
181  
15.1  
180  
225  
15.7  
213  
266  
15.5  
245  
307  
Evaporatord  
Condenserse  
Nominal water flow (gpm)  
Condenser connection (no manifold) Flange Conn. (in.)  
Evaporator manifold connection Victaulic  
2.5  
3
3
4
Amp draw, nameplate  
(460/3/60 V)f  
Water-cooled  
112  
130  
138  
170  
Height  
Width  
Depth  
85  
100  
45  
74  
115  
72  
Dimensions (in.)  
Shipping weight (lbs)  
Max operating weight (lbs.)  
3,266  
3,468  
3,512  
3,754  
4,336  
4,594  
4,982  
5,246  
c
d
e
f
Based on 50ºF (10ºC) chilled water supply temperature and 85ºF (29ºC) tower water.  
Based on 2.4 gpm per ton (9.1 lpm per 3.517 kW).  
Based on availability of 85ºF (29ºC) tower water at 25 psi (172.4 kPa/1.7 bars) minimum.  
Multiply 460/3/60 amperage by 2.0 for 208-230/3/60 amperages; multiply by 1.2 for 380/3/60 amperages; multiply by 0.8 for  
575/3/60 amperages  
Page 12 of 77  
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Model  
SCWW-xxx  
115  
116.3  
145  
146.0  
165  
166.3  
195  
193.1  
Cooling Capacity (tons) @ 50°F LWTc  
Capacity stages  
Infinite Unloading  
EER (BTUH/W)  
15.5  
279  
349  
3
16.2  
350  
438  
15.9  
399  
499  
4
16.2  
463  
579  
Evaporatord  
Condenserse  
Nominal water flow (gpm)  
Condenser connection (no manifold) Flange Conn. (in.)  
Evaporator manifold connection Victaulic  
4
6
Amp draw, nameplate  
(460/3/60 V)f  
Water-cooled  
216  
250  
282  
316  
Height  
Width  
Depth  
77  
124  
72  
81  
137  
75  
Dimensions (in.)  
Shipping weight (lbs)  
Max operating weight (lbs.)  
5,298  
5,584  
8,844  
9,428  
9,376  
10,102  
9,580  
10,364  
c
d
e
f
Based on 50ºF (10ºC) chilled water supply temperature and 85ºF (29ºC) tower water.  
Based on 2.4 gpm per ton (9.1 lpm per 3.517 kW).  
Based on availability of 85ºF (29ºC) tower water at 25 psi (172.4 kPa/1.7 bars) minimum.  
Multiply 460/3/60 amperage by 2.0 for 208-230/3/60 amperages; multiply by 1.2 for 380/3/60 amperages; multiply by 0.8 for  
575/3/60 amperages  
SCW Series Central Chilling Stations  
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Figure 2  
Typical Two-Circuit 60-195 Ton Remote Air Cooled Chiller  
Model  
SCWR-xxx  
60  
75  
90  
100  
Cooling Capacity (tons) @ 50°F LWT  
Capacity stages  
53.8  
67.1  
Infinite Unloading  
79.1  
91.2  
EER (BTUH/W)  
9.4  
9.9  
9.8  
10  
Nominal water flow (gpm)  
Evaporator  
129  
161  
190  
219  
Evaporator manifold connection Victaulic  
No. of condenser fans per condenser  
3
4
3
3
4
4
Amp draw, nameplate  
(460/3/60 V)  
Chiller  
112  
11  
130  
11  
138  
14  
170  
14  
Condensers (per condenser)  
Dimensions (in.) of chiller  
Height  
Width  
Depth  
75  
100  
45  
74  
115  
72  
Dimensions (in.) of each  
condenser  
Height  
Width  
Depth  
50  
45.5  
180  
45.5  
235  
Shipping weight (lbs)  
Chiller  
2,574  
1,190  
2,600  
1,215  
2,676  
1,210  
2,710  
1,240  
3,456  
1,580  
3,498  
1,650  
3,532  
1,620  
3,580  
1,660  
Condensers (each condenser)  
Chiller  
Condensers  
Max operating weight  
(lbs.)  
SCWR-xxx  
Model  
115  
104.1  
145  
130.5  
165  
148.4  
195  
174.0  
Cooling Capacity (tons) @ 50°F LWT  
Capacity stages  
Infinite Unloading  
EER (BTUH/W)  
Nominal water flow (gpm)  
10.3  
250  
10.5  
10.4  
10.2  
418  
Evaporator  
313  
356  
Evaporator manifold connection Victaulic  
No. of condenser fans per condenser  
4
4
6
6
5
8
Amp draw, nameplate  
(460/3/60 V)  
Dimensions (in.) of chiller  
Chiller  
216  
14  
77  
124  
72  
250  
18  
282  
21  
81  
137  
75  
316  
28  
Condensers (per condenser)  
Height  
Width  
Depth  
Dimensions (in.) of each  
condenser  
Height  
Width  
Depth  
50  
45.5  
290  
88  
235  
235  
345  
Shipping weight (lbs)  
Chiller  
4,156  
1,760  
4,212  
1,800  
7,528  
2,380  
7,788  
2,435  
7,554  
2,480  
7,814  
2,540  
7,698  
3,230  
8,016  
3,300  
Condensers (each condenser)  
Chiller  
Condensers (each condenser)  
Max operating weight  
(lbs.)  
c
d
Based on 50ºF (10ºC) chilled water supply temperature and 95ºF (35ºC) ambient air.  
Based on 2.4 gpm per ton (9.1 lpm per 3.517 kW)  
e
Multiply 460/3/60 amperage by 2.0 for 208-230/3/60 amperages; multiply by 1.2 for 380/3/60 amperages; multiply by 0.8 for  
575/3/60 amperages  
Page 14 of 77  
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SCWR Series Remote Condenser Models  
Fan(s)  
Refrigeration d  
Connections  
Each  
Charge  
R-134a  
lbs. e  
Model  
Number  
Dia.  
in.  
Motor  
hp c  
Amps  
460V Fans cfm e  
Air flow Discharge  
Liquid  
ODS(in.)  
ODS(in.)  
1
1
SCWR60  
SCWR75  
SCWR90  
SCWR100  
SCWR115  
SCWR145  
SCWR165  
SCWR195  
30 1 ½ hp 3 ø 11.0  
30 1 ½ hp 3 ø 11.0  
30 1 ½ hp 3 ø 14.0  
30 1 ½ hp 3 ø 14.0  
30 1 ½ hp 3 ø 14.0  
30 1 ½ hp 3 ø 18.0  
30 1 ½ hp 3 ø 21.0  
30 1 ½ hp 3 ø 21.0  
3
3
4
4
4
5
6
8
34,800  
32,900  
46,400  
42,400  
41,500  
51,800  
65,800  
87,800  
2 /8  
2 /8  
19  
19  
22  
27  
27  
43  
50  
44  
1
1
2 /8  
2 /8  
1
1
2 /8  
2 /8  
1
1
2 /8  
2 /8  
1
1
2 /8  
2 /8  
5
5
2 /8  
2 /8  
5
5
2 /8  
2 /8  
1
1
2 @ 2 /8  
2 @ 2 /8  
c
d
e
ø represents electrical phase; all motors are 1,140 rpm. Multiply hp by 0.746 to convert to kW.  
Refrigeration charge is for remote condenser only!  
To convert cfm to cmh, multiply by 1.699. To convert lbs. to Kg, multiply by 0.454.  
SCW Series Central Chilling Stations  
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2
Shipping Information  
2-1 Unpacking and Inspection  
You should inspect your equipment for possible shipping damage.  
Thoroughly check the equipment for any damage that might have  
occurred in transit, such as broken or loose wiring and  
components, loose hardware and mounting screws, etc.  
2-2 In the Event of Shipping Damages  
According to the contract terms and conditions of the Carrier, the  
responsibility of the Shipper ends at the time and place of  
shipment.  
Notify the transportation company’s local agent if you discover  
damage  
Hold the damaged goods and packing material for the examining  
agent’s inspection. Do not return any goods before the  
transportation company’s inspection and authorization.  
File a claim with the transportation company. Substantiate the  
claim by referring to the agent’s report. A certified copy of our  
invoice is available upon request. The original Bill of Lading is  
attached to our original invoice. If the shipment was prepaid, write  
us for a receipted transportation bill.  
Advise customer service regarding your wish for assistance and to  
obtain an RMA (return material authorization) number.  
Page 16 of 77  
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2-3 If the Shipment is Not Complete  
Check the packing list as back-ordered items are noted on the  
packing list. In addition to the equipment itself, you should have:  
; ................. Bill of lading  
; ................. Packing list  
; ................. Operating and Installation packet  
; ................. Electrical schematic and panel layout drawings  
; ................. Component instruction manuals (if applicable)  
Re-inspect the container and packing material to see if you missed  
any smaller items during unpacking.  
2-4 If the Shipment is Not Correct  
If the shipment is not what you ordered, contact the parts and  
service department immediately at (262) 641-8610. Have the  
order number and item number available. Hold the items until you  
receive shipping instructions.  
2-5 Returns  
Do not return any damaged or incorrect items until you receive  
shipping instructions from the shipping department.  
SCW Series Central Chilling Stations  
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2-6 Uncrating Your New Chiller  
! WARNING !  
DUE TO THE SIZE AND WEIGHT OF SCW SERIES CHILLERS,  
STERLING RECOMMENDS USING BONDED PROFESSIONAL  
MILLWRIGHTS TO UNLOAD AND MOVE SCW SERIES CHILLERS.  
Rig the chiller from the frame only, using spreader bars to prevent  
load transfer to any chiller components. Rig the frame from at least  
four points and balance the load before lifting to clear the skid. Use  
a forklift of adequate size when lifting the chiller by the fork  
pockets.  
Insert the forks all the way into the pockets and be sure to balance  
the load before lifting the chiller to clear the skid. Lift only as high  
as necessary. Use a pry bar to free the skid if necessary. Lower  
slowly. Retain the crating in case reshipment is necessary due to  
hidden shipping damage.  
Caution!  
Due to the weight of these units, use extreme caution  
when moving and placing SCW Series chillers.  
.
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- Notes -  
SCW Series Central Chilling Stations  
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3
Installation  
3-1 Installation Location Considerations  
As with all equipment installations, follow all applicable codes and  
regulations.  
; Locate close to the process to reduce piping expense.  
; Locate adjacent to drain and city water sources.  
; Consult a structural engineer to assure that the floor, mounting  
pad or structural steel support is of adequate strength.  
; Allow for required service clearances necessary for condenser  
maintenance and easy access to all components.  
3-2 Making Electrical Connections  
SCW Series systems are designed for three-phase voltage  
operation. Refer to the unit nameplate for proper voltage and  
amperage requirements.  
Make sure you provide a correctly sized and protected supply of  
electrical power to the unit.  
Important!  
Refer to National Electric Code (NEC) Article 430-24 through 430-26  
for proper feeder conductor and supply disconnect sizing.  
Maintain a safe ground and disconnect the power supply before  
servicing the unit. A qualified electrician should make electrical  
connections, and disconnect and lock out electricity using OSHA  
29 CFR 1910.147 standards when you need a service call.  
Check serial tag voltage and amperage requirements and make sure  
your electrical service conforms before making any electrical  
connections. Total running amps for the SCW Series systems are  
listed on the nameplate. Customer connections can be run to the  
supply terminals from either side of the unit. Make sure that all  
three phases are wired correctly. If not wired properly, the unit will  
run backwards. Again, check the unit nameplate for correct  
voltage and amperage.  
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! DANGER  
Improper electrical connections  
will damage the unit and cause  
serious operator injury or death!  
Compressor damage will occur if  
compressors are run backwards.  
Bring properly sized power leads and ground from a fused  
disconnect (installed by your electrician) to the unit. Provide  
external overcurrent protection to the unit, using circuit breakers or  
fuses. If you use fuses, make sure that they are dual-element time-  
delay fuses, sized according to your electrical code. Make sure that  
all electrical connections are tight.  
Important!  
1. Electrical connections must comply with all applicable electrical codes.  
2. The chiller must be grounded in accordance with NEC Article 250.  
3. Voltage must be within plus or minus ten percent (±10%) of the nameplate  
rating.  
4. Make sure your installer provides external protection.  
Check Compressor Rotation Before Starting Unit!  
1. Connect a phase monitor and phase incoming power ABC.  
2. Connect a refrigerant gauge to the suction service valve. Fully front seat  
the service valve and open one full turn.  
3. Bump start the compressor by switching off then on quickly 0.5 to 1  
second. If the rotation is correct, the suction pressure will drop  
immediately. A rise in pressure will indicate the wrong rotation. If this  
occurs, change over two electrical phases of the incoming power supply  
(do not change phase at the compressor starter).  
Check the electrical wiring schematic  
provided in your Customer Information packet  
for additional information.  
SCW Series Central Chilling Stations  
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Note:  
• Never switch contactor leads or motor leads for reversing  
rotation.  
• Do not use contactor or motor leads for phase matching.  
• Compressor damage will occur if the compressor is run in  
reverse. The compressor motor protector checks for correct  
phasing and will not allow it to start in reverse.  
• If you discover that compressor rotation is reversed, correct it  
by switching any two main power leads into the disconnect  
switch or distribution block on the unit.  
Check your work and proceed to the following Piping Considerations section.  
3-3 Piping Considerations  
Piping systems vary with process application and pump tank  
configuration. Typical system configuration drawings are provided  
in this manual; the details may or may not apply to your  
application. Piping systems must be designed by a person  
knowledgeable in piping system design and configuration.  
Sterling’s Contracting Department can design and install a piping  
system tailored to your process.  
• All water piping returning to the pump tank must be equipped  
with an inverted trap with a vacuum breaker at the high point  
of the system to prevent mains from siphoning into the pump  
tank.  
• Run mains full size in order to reduce pressure drop in the  
system and provide maximum pressures at the ends of the  
mains.  
3-4 Making Process Water Connections  
All Models  
All SCW Series chilling stations have two chilled water  
connections per unit, and on water-cooled models, one more set of  
water connections for condenser water:  
To Process  
The chilled water supply outlet leading to the process being  
controlled.  
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From Process  
The chilled water return for water returning back to the chiller  
from the process to be cooled and recirculated. Adjust the  
butterfly valve for the pressure drop that corresponds to the model  
number of the chiller. Pressure drop is equal to supply pressure  
minus return pressure  
Model  
Number  
Water Side Pressure Drop  
Condenser (each) Evaporator (each)  
Flow (gpm) PD (psi) Flow (gpm) PD (psi)  
72 5.3  
SCWW/R60  
SCWW/R75  
SCWW/R90  
SCWW/R100  
SCWWR115  
SCWW/R145  
SCWW/R165  
SCWW/R195  
91  
102  
117  
150  
166  
196  
219  
278  
4.0  
4.7  
4.4  
5.5  
4.3  
4.1  
4.1  
4.7  
90  
4.5  
5.6  
3.9  
3.0  
4.8  
4.6  
6.0  
107  
123  
140  
175  
200  
232  
3-5 Making Tank Piping Connections  
If you have purchased the SCW Series central chilling station with  
the integral pump tank, please proceed with this section.  
Return  
Bring the chilled water returning from the process to the pump  
tank warm From Process side. This line is sized according to the  
flow rate from the process to the pump tank. See Section 3-3 on  
Page 21 for more information on piping considerations.  
Important!  
Do not use the SCW Series unit to support piping.  
Makeup  
Overflow  
To Drain  
Connect a city water source to maintain water level in the pump  
tank.  
Connect the OVERFLOW outlet to an approved, trapped drain to  
permit excess water in the pump tank to overflow to the drain. The  
overflow line is sized according to the size of the pump tank.  
Connect to a 1½” line (approx. 63 mm) leading to an approved,  
trapped drain. You can drain the pump tank if necessary.  
SCW Series Central Chilling Stations  
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3-6 Water Connection Sizing Considerations  
Important!  
• Run all external chilled water connections with adequate size to the  
process.  
• Provide the largest possible openings and passages for the flow of chilled  
water through platens, dies, molds, or other pieces of equipment.  
• Minimum external pressure drop is critical for proper operation.  
3-7 Galvanic Corrosion Considerations  
Water circuit piping components are primarily ferrous (iron) and  
react electro-chemically with non-ferrous metallic materials such  
as copper. Some water has dissolved minerals that will greatly  
accelerate the reaction between dissimilar metals.  
Use PVC or ferrous piping to minimize galvanic action. If piping  
must be copper, use dielectric unions at the chiller.  
3-8 Water Treatment Considerations  
Water treatment is important in any piping system. In some  
locations, raw water may be used in the system without problem;  
in other locations, it will result in large deposits of scale and  
corrosion.  
Sterling offers a complete line of water treatment equipment.  
Contact your Sterling sales representative for water testing and  
treatment options.  
3-9 Making Water-Cooled Condenser Connections  
SCW Series water-cooled chilling stations use city or tower water  
as a cooling medium. All external condenser supply and discharge  
piping and connections should be of adequate size. Water  
regulating valves are not required on the SCW Central Chiller if  
the tower water does not fall below 65°F (18ºC). Water flow must  
be adjusted based upon the pressure drop in the following table on  
the next page.  
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Two connections are made to each SCW Series unit:  
Condenser Water In  
Condenser Water Out  
The city or tower water supply inlet is located at the side or rear of  
the chiller.  
• Water pressure ≥ 25 psi (≥ 172.4 kPa/≥ 1.72 bars)  
• Water temperature ≤ 85°F (≤ 29ºC)  
The return outlet, located at the chiller side or rear is connected to  
a cooling tower inlet, a sewer or other approved discharge receiver.  
• A water regulating valve is an optional feature in the  
condenser water out line.  
• Adjust the butterfly valve for the pressure drop that  
corresponds to the model number of the chiller. Pressure drop  
is equal to supply pressure minus return pressure. (If a water  
regulating valve has been supplied, adjustment is not required.)  
Water Side Pressure Drop  
Model  
Number  
Condenser (each)  
Flow (gpm) PD (psi)  
Evaporator (each)  
Flow (gpm) PD (psi)  
72 5.3  
SCWW/R60  
SCWW/R75  
SCWW/R90  
SCWW/R100  
SCWWR115  
SCWW/R145  
SCWW/R165  
SCWW/R195  
91  
102  
117  
150  
166  
196  
219  
278  
4.0  
4.7  
4.4  
5.5  
4.3  
4.1  
4.1  
4.7  
90  
4.5  
5.6  
3.9  
3.0  
4.8  
4.6  
6.0  
107  
123  
140  
175  
200  
232  
3-10 Installing the Remote Air-Cooled Condenser  
SCW Series models use the surrounding air to cool the remote  
condenser. All models have variable speed fans and low ambient  
controls to allow proper operation down to -20°F (-29ºC) outdoor  
air temperature.  
Install the remote air cooled condenser where there is:  
• Greater than or equal to -20°F (-29ºC) air temperature.  
• Free passage of air for condensing.  
• Adequate structural support.  
• Protection from strong winds and drifting snow.  
• Provisions for removal of heated air from the area.  
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• No steam, hot air or fume exhausts drawn into the condenser  
coils.  
• Service accessibility.  
SCW Series condensing pressure  
with 95ºF (35ºC) condenser air  
R-134a = 171 psi (1,179 kPa/11.79 bars)  
Note: Due to the variables involved in remote air-cooled condenser installations, no set or  
standard piping procedure exists. Each installation must be designed and installed by  
qualified persons. Follow the instructions supplied with the condenser.  
3-11 Checking Motor Direction  
Compressor  
Check Compressor Rotation Before Starting Unit!  
1. Connect a phase monitor and phase incoming power ABC.  
2. Connect a refrigerant gauge to the suction service valve. Fully front seat  
the service valve and open one full turn.  
3. Bump start the compressor by switching off then on quickly 0.5 to 1  
second. If the rotation is correct, the suction pressure will drop  
immediately. A rise in pressure will indicate the wrong rotation. If this  
occurs, change over two electrical phases of the incoming power supply  
(do not change phase at the compressor starter).  
Note:  
• Never switch contactor leads or motor leads for reversing  
rotation.  
• Do not use contactor or motor leads for phase matching.  
• Compressor damage will occur if the compressor is run in  
reverse. The compressor motor protector checks for correct  
phasing and will not allow it to start in reverse.  
• If you discover that compressor rotation is reversed, correct it  
by switching any two main power leads into the disconnect  
switch or distribution block on the unit.  
Water Pump  
A positive pressure of 20 to 30 psi (137.9 to 206.8 kPa/1.38 to 2.07  
bars) on the TO PROCESS line indicates correct pump rotation.  
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Condenser Fan  
On SCW Series remote air-cooled units, air should be drawn  
through the condenser and discharge up from the condenser.  
Changing fan rotation direction  
• Disconnect and lock out power at the fused disconnect.  
• If all fans are going backwards, reverse any two main power  
leads.  
• If only some of the fans are going backwards, switch any two of  
their respective motor leads.  
-Notes-  
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4
Sequence Of Operation  
4-1 Staging  
1. The system uses a PID control algorithm to regulate the  
chilled water temperature. As the required control effort  
increases or decreases, the system compressors are  
infinitely unloaded or turned on/off to keep the temperature  
at the specified set-point.  
2. Compressor anti-recycle time is two (2) minutes.  
4-2 Alarms  
If a fault occurs, that compressor or circuit is deactivated. The  
load will automatically shift to any other compressors that are  
currently ON-LINE, but not running. Lead/Lag rotation will  
continue to function. Compressors that are faulted will be  
removed from the rotation order.  
4-3 Lead-Lag Compressors  
The system automatically rotates the compressor order to generate  
a Lead/Lag rotation. Any time a compressor is faulted or manually  
taken OFF-LINE, it will be removed from the Lead/Lag rotation.  
Once the fault is cleared or manually put ON-LINE, the  
compressor is returned to the Lead/Lag rotation at the end of the  
rotation order.  
4-4 Lead-Lag Pumps  
The system automatically rotates the pump order to generate a  
Lead/Lag rotation. Any time a pump is faulted or manually taken  
OFF-LINE, it will be removed from the Lead/Lag rotation. Once  
the fault is cleared or manually put ON-LINE, the pump is returned  
to the Lead/Lag rotation at the end of the rotation order.  
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4-5 Chilled Water Circuit  
If your central chilling station is equipped with the optional  
integral pump tank, make the process cooling water supply  
connection at the P1 manifold at the left side of the pump tank at  
the exposed connection. Bring the process cooling water return  
connection to the Hot well of the tank on the right side at the  
flanged connection.  
Warm coolant (water and ethylene glycol mixture) returns from the  
process to the tank, then gets pumped through the evaporator  
where it is cooled. The coolant flows to the process and returns to  
repeat the cycle.  
4-6 Refrigeration Circuit  
• SCW Series chilling station air- and water-cooled unit  
refrigeration cycles differ only in the way the compressed gas  
is condensed to a liquid.  
• Liquid refrigerant from the condenser passes through a shut-off  
valve into a filter/dryer.  
• The refrigerant then passes through the sight glass and solenoid  
valves into the thermal expansion valve which regulates flow;  
the valve lowers pressure and boiling point. Heat from the fluid  
causes the refrigerant to boil off into a vapor.  
• The refrigerant vapor flows through the suction line back into  
the compressor.  
• The refrigerant gives up heat as it re-condenses to a liquid in  
the condenser.  
4-7 Freezestat Control  
The freezestat shuts down the compressor if the chilled water  
temperature approaches the freezing point. The chilled water pump  
on the system will continue to run. It is factory-set at 40°F (4ºC) or  
10°F (6ºC) below the rated capacity operating temperature of 50°F  
(10ºC).  
SCW Series Central Chilling Stations  
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If you want lower chilled water temperatures, you’ll need to mix  
process water with industrial- (not automotive) grade ethylene or  
propylene glycol with rust inhibitor to provide protection down to  
20°F (12ºC) below the operating temperature you want. Figure 3  
below shows the proper mixtures needed to provide protection to  
20°F (12ºC) below the operating temperature you want. You can  
then reset the freezestat cutout temperature to a temperature of  
10°F (6ºC) below the operating temperature you selected.  
Caution!  
Make sure all freezestat adjustments are performed  
by a qualified refrigeration service technician.  
The Sterling product warranty does not cover system freeze-up!  
Figure 3  
Freezing Protection Curve  
Ethylene glycol required for evaporator freeze protection  
60  
50  
40  
Ethylene  
glycol  
30  
percent by  
volume  
20  
10  
0
-50ºF -40ºF -30ºF -20ºF -10ºF 0ºF 10ºF 20ºF 30ºF 40ºF 50ºF 60ºF  
-46ºC -40ºC -34ºC -29ºC -23ºC -18ºC -12ºC -7ºC -1ºC 4ºC 10ºC 16ºC  
Chilled water operating temperature ºF / ºC  
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4-8 High Pressure Cutout  
This electro-mechanical safety feature opens the control circuit if  
the system condensing pressure exceeds a safe level.  
High pressure cutout setting  
Model  
SCW Series water-cooled and remote air-cooled  
chilling stations  
psi  
kPa  
bars  
290 psi  
2,000 kPa  
20 bars  
Important!  
The high pressure cutout is a manual reset control,  
so you should reset it once.  
If the problem persists, call a refrigeration service technician  
to analyze the problem and to reset the control.  
4-9 Low Pressure Cutout  
This encapsulated switch safety feature prevents the compressor  
suction pressure from dropping below a pre-set point. It is factory  
set to open the control circuit when pressure drops below a safe  
level. The chiller will restart when the suction pressure reaches 30  
psi (206.9 kPa/2.1 bars).  
Opens control circuit @  
psi kPa bars  
Resets control circuit @  
psi kPa bars  
Model  
SCW Series water-cooled and  
remote air-cooled chilling stations  
15 psi 103.4 kPa 1.0 bars 30 psi 206.9 kPa 2.1 bars  
4-10 Flow Switch  
The flow switch shuts down the chiller if the evaporator water flow  
falls below a safe operating gallons-per-minute (liters-per-minute)  
flow rate.  
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4-11 Control Nozzle  
All SCW Series chilling station evaporators have two control  
nozzles. The flow switch, freezestat, and flush port are located in  
the control nozzle. Pressure gages are mounted in the control  
nozzles to aid in achieving proper flow through the evaporator and  
balancing flows.  
Pressure drop between evaporator entering water pressure and  
evaporator leaving water pressure can be converted to gallons per  
minute using the pressure drop charts below.  
Water Side Pressure Drop  
Model  
Number  
Condenser (each)  
Flow (gpm) PD (psi)  
Evaporator (each)  
Flow (gpm) PD (psi)  
72 5.3  
SCWW/R60  
SCWW/R75  
SCWW/R90  
SCWW/R100  
SCWWR115  
SCWW/R145  
SCWW/R165  
SCWW/R195  
91  
102  
117  
150  
166  
196  
219  
278  
4.0  
4.7  
4.4  
5.5  
4.3  
4.1  
4.1  
4.7  
90  
4.5  
5.6  
3.9  
3.0  
4.8  
4.6  
6.0  
107  
123  
140  
175  
200  
232  
4-12 Control Probe  
Two control probes sense temperatures. One probe measures the  
temperature of the hot well and the other does the same for the  
cold well of the reservoir. These temperatures are used by the PLC  
controller to sequence the compressors, based on load.  
4-13 Chilled Water Manifold  
The chilled water manifold allows one-point connections of TO  
PROCESS piping. The Sch. 40 steel piping includes butterfly  
valves at each evaporator for flow balancing and circuit isolation;  
optional pressure gauges can be installed.  
4-14 Optional Condenser Water Manifold  
The optional condenser water manifold allows one-point  
connection of TO TOWER (drain) and FROM TOWER (city water)  
piping. Sch. 40 steel include butterfly valves for each condenser.  
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- Notes -  
SCW Series Central Chilling Stations  
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5
Startup Checklists  
5-1 Introduction  
Important!  
These lists assume the installation information  
in this manual has been read and followed.  
Have new chillers started up and checked  
by a qualified refrigeration service technician.  
Sterling offers factory startup for SCW Series chilling stations.  
Call the Sterling Service Department  
at 1 (800) 233-4819 for more details.  
5-2 Water-Cooled SCW Series Startup Checklist  
; Check the shipping papers against the serial tag to be sure  
chiller size, type and voltage is correct for the process.  
; Check the transformer primary voltage connections to be sure  
they are configured for the electrical power you are using.  
; The voltage at the main power connection must be within plus  
or minus ten percent (±10%) of the voltage listed on the serial  
tag.  
; Phase imbalance must be less than two percent (<2%).  
; Electrical connections must conform to all applicable codes.  
; Complete the chilled water TO PROCESS and FROM  
PROCESS connections.  
; The optional or field installed chilled water supply and return  
valves on the chiller must be open.  
; Be sure the pump tank and chilled water circuit are filled with a  
water/glycol mixture that provides freeze protection to 20°F  
(12ºC) below the leaving water temperature you want.  
; Complete the tower or city condenser WATER IN and WATER  
OUT connections. Provide an adequate condenser water  
supply; 2 gpm per ton for city water or 3 gpm per ton for tower  
water operation.  
; Remove all tools, foreign matter and debris from the pump  
tank reservoir and piping.  
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; Complete all piping leading to and from the pump tank.  
Observe all applicable codes.  
; Complete all electrical wiring. Observe all applicable codes.  
; Prepare all related equipment in the system for operation.  
; Check for proper compressor rotation direction. To confirm  
proper rotation:  
1. Connect a phase meter and phase incoming power  
ABC.  
2. Connect a refrigerant gauge to the suction service  
valve. Fully front seat the service valve and open one  
full turn.  
3. Bump start the compressor by switching off then on  
quickly 0.5 to 1 second. If the rotation is correct, the  
suction pressure will drop immediately. A rise in  
pressure will indicate the wrong rotation. If this occurs,  
change over two electrical phases of the incoming  
power supply (do not change phase at the compressor  
starter).  
Note:  
• Never switch contactor leads or motor leads for reversing  
rotation.  
• Do not use contactor or motor leads for phase matching.  
• Compressor damage will occur if the compressor is run in  
reverse. The compressor motor protector checks for correct  
phasing and will not allow it to start in reverse.  
• If you discover that compressor rotation is reversed, correct  
it by switching any two main power leads into the  
disconnect switch or distribution block on the unit.  
; Open the 1” (approx. 25 mm) makeup water valve and allow  
the tank to fill until the automatic float valve shuts off. The  
float level should be adjusted so the standing water level is 8”  
(20 cm) from the top of the tank.  
; Close the discharge butterfly valve, crack it open, then start the  
pump and observe the gauge.  
; Check for proper pump rotation direction. To confirm proper  
rotation:  
1. Observe a pump pressure gauge connected to the  
suction and discharge sides of the pump casing through  
two ¼” (approx. 6.4 mm) gauge cocks.  
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2. Close the gauge cock leading to the pump suction and  
open the gauge cock leading to the pump discharge.  
3. Close the discharge butterfly valve, crack it open, then  
start the pump and observe the gauge.  
• If the gauge indicates within 15 psi (103.4 kPa/1.03  
bars) below the pump curve, pump rotation is  
correct. Pump rotation is clockwise opposite the  
shaft end.  
• If the gauge indicates 20 psi (137.9 kPa/1.38 bars)  
or more below the pump curve, the pump is running  
backwards. Reverse rotation by interchanging any  
two power mains to the pump motor or starter.  
• Recheck the pressure to be sure it increased.  
; Check the water level in the pump tank to be sure the pump  
does not run dry while the system piping is being filled.  
; Check your work and proceed to the Startup procedure.  
5-3 Water-Cooled SCW Series Startup  
1. Start the chiller by pushing the Start button on the control  
panel of the unit.  
2. The screen will display the Main Menu screen.  
3. If your chiller has been setup to control the pump tank, the  
recirculation pump will turn on first, then after 5 seconds  
the process pump will turn on. If configured with a standby  
pump, the lead/lag will control which pump turns on.  
4. Fifteen (15) seconds after the last pump turns on the first  
compressor will turn on. Based on the temperature of the  
water, the controller will turn on compressors every 15  
seconds.  
5. Adjust the Freezestat cut-out, located in the main electrical  
enclosure, to 10°F (6ºC) below the process temperature set  
point you want.  
Note: If the recirculation pump does not turn on (or that the flow switch is not satisfied) the  
compressors will not be allowed to turn on.  
6. Check the pump(s) amp draws and pressures. The amp  
draws must be within the pump(s) running load and service  
factor amps.  
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7. Operate the chiller, looking for leaks and listening for  
unusual noises or vibrations that could indicate improper  
operation.  
5-4 Remote Air-Cooled SCW Series Startup Checklist  
; Check the shipping papers against the serial tag to be sure  
chiller size, type and voltage is correct for the process.  
; Check the transformer primary voltage connections to be sure  
they are configured for the electrical power you are using.  
; The voltage at the main power connection must read within  
plus or minus ten percent (±10%) of the voltage listed on the  
serial tag.  
; Phase imbalance must be less than two percent (<2%).  
; Electrical connections must conform to all applicable codes.  
; Complete the chilled water TO PROCESS and FROM  
PROCESS connections.  
; The optional or field installed chilled water supply and return  
valves must be open.  
; Be sure the tank and chilled water circuit piping are filled with  
a water/glycol mixture. The water/glycol mix should provide  
freeze protection to 20°F below the leaving water temperature  
you’ve selected.  
; The air cooled condenser should have an adequate supply of air  
for proper operation.  
; Connect the main power to the unit and bump-start it to check  
for proper rotation direction. If the fans are operating  
backwards, reverse any two main power leads at the incoming  
terminal block.  
; Remove all tools, foreign matter and debris from the pump  
tank reservoir and piping.  
; Complete all piping leading to and from the pump tank.  
Observe all applicable codes.  
; Complete all electrical wiring. Observe all applicable codes.  
; Prepare all related equipment in the system for operation.  
; Check for proper compressor rotation direction. To confirm  
proper rotation:  
1. Connect a phase meter and phase incoming power ABC.  
SCW Series Central Chilling Stations  
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2. Connect a refrigerant gauge to the suction service valve.  
Fully front seat the service valve and open one full turn.  
3. Bump start the compressor by switching off then on  
quickly 0.5 to 1 second. If the rotation is correct, the  
suction pressure will drop immediately. A rise in pressure  
will indicate the wrong rotation. If this occurs, change over  
two electrical phases of the incoming power supply (do not  
change phase at the compressor starter).  
Note:  
• Never switch contactor leads or motor leads for reversing  
rotation.  
• Do not use contactor or motor leads for phase matching.  
• Compressor damage will occur if the compressor is run in  
reverse. The compressor motor protector checks for correct  
phasing and will not allow it to start in reverse.  
• If you discover that compressor rotation is reversed, correct it  
by switching any two main power leads into the disconnect  
switch or distribution block on the unit.  
; Open the 1” (approx. 25 mm) makeup water valve and allow  
the tank to fill until the automatic float valve shuts off. The  
float level should be adjusted so the standing water level is 8”  
(20 cm) from the top of the tank.  
; Check for proper pump rotation direction. To confirm proper  
rotation:  
1.  
Observe a pump pressure gauge connected to the suction  
and discharge sides of the pump casing through two ¼”  
(approx. 6.4 mm) gauge cocks.  
2.  
3.  
Close the gauge cock leading to the pump suction and open  
the gauge cock leading to the pump discharge.  
Close the discharge butterfly valve, crack it open, then start  
the pump and observe the gauge.  
• If the gauge indicates within 15 psi (103.4 kPa/1.03 bars)  
below the pump curve, pump rotation is correct. Pump  
rotation is clockwise opposite the shaft end.  
• If the gauge indicates 20 psi (137.9 kPa/1.38 bars) or more  
below the pump curve, the pump is running backwards.  
Reverse rotation by interchanging any two power mains to  
the pump motor or starter.  
• Recheck the pressure to be sure it increased.  
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; Check the water level in the pump tank to be sure the pump  
does not run dry while the system piping is being filled.  
; Check your work and proceed to the Startup procedure in the  
following section.  
5-5 Remote Air-Cooled SCW Series Startup  
1. Start the chiller by pushing the Start button on the control  
panel of the unit.  
2. The touchscreen will display the Main Menu screen.  
3. If your chiller has been setup to control the pump tank, the  
recirculation pump will turn on first, then after 5 seconds  
the process pump will turn on. If configured with a standby  
pump, the lead/lag will control which pump turns on.  
4. Fifteen (15) seconds after the last pump turns on, the first  
compressor will turn on. Based on the temperature of the  
water, the controller will turn on compressors every 15  
seconds.  
5. Adjust the Freezestat cut-out, located in the main electrical  
enclosure, to 10°F (6ºC) below the process temperature set  
point you want.  
Note: If the recirculation pump does not turn on (or that the flow switch is not satisfied) the  
compressors will not be allowed to turn on.  
6. Check the pump(s) amp draws and pressures. The amp  
draws must be within the pump(s) running load and service  
factor amps.  
7. Operate the chiller, looking for leaks and listening for  
unusual noises or vibrations that could indicate improper  
operation.  
8. Check condenser fans for pressure switch settings as shown  
in the table below:  
Fan  
number  
Set on  
kPa  
Set off  
kPa  
psi  
bars  
psi  
bars  
1
2
3
4
5
Not applicable; Fan 1 is a variable-speed fan  
155  
170  
185  
200  
1,069  
1,172  
1,276  
1,379  
10.7  
11.7  
12.8  
13.8  
120  
135  
150  
165  
828  
931  
1035  
1,138  
8.3  
9.3  
10.3  
11.4  
SCW Series Central Chilling Stations  
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5-6 Determining Flow Rate  
To determine flow:  
1. Close the gauge cock leading to the pump suction side and  
open the gauge cock leading to the pump discharge.  
2. Start the pump and make note of the discharge pressure in  
psi (kPa/bars).  
3. Check the pump curve for the appropriate horsepower  
pump at the discharge pressure psi.  
4. Project this point down to find the flow in gpm (lpm).  
5. Process pumps can be left wide open if running amps are  
below full load amps.  
5-7 Shutdown  
1. Ready process and related equipment for shut down.  
2. Donot turn off main power until chiller completes the shut-  
down sequence (approximately 2 minutes).  
3. Close the water make up valve.  
4. If the system is to be drained, open the 2” drain valve.  
Figure 4  
SCW Series Standard Control Panel  
Figure 5  
SCW Series Advanced Control Panel  
-Notes-  
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6
Graphic Panel Devices  
6-1 Indicator Lights and Control Switches (MMI)  
System On  
The green System On indicator lights when the main power  
switch is on and the control circuit is energized.  
Start  
The Start push-button lets you energize the unit.  
Stop  
The Stop push-button lets you de-energize the unit.  
Touchscreen Interface  
The color touchscreen interface gives you control over the chilling  
station. It has an easy-to-use control menu that lets you quickly  
change or adjust chiller settings and also gives you all the  
operation information you need to control the unit effectively.  
See Chapter 7 on Page 43 for more information on the Standard  
touchscreen interface operation. See Chapter 8 on Page 57 for  
more information on the Advanced touchscreen interface  
operation.  
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-Notes-  
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Using the Standard  
Operator Interface  
7
7-1 Operator Interface Introduction  
The Standard touchscreen interface lets you control your SCW  
Series central chilling station. You can do such things as:  
• Control compressors and optional pumps  
• View current statuses of operation, such as pressures,  
temperatures, and capacities  
• Handle alarm conditions  
The sections in this chapter list special instructions for the standard  
operator interface.  
Note: The screens shown in this chapter are sample screens.  
Actual screen representations may be slightly different in  
appearance, but are no different in operation.  
On all screens in this controller, the F4 button is reserved for the  
previous screen function. Some screens, such as the chiller status  
screen, do not have sufficient space to display a prompt that the F4  
performs this function. However, the F4 button will always move  
to the previous screen and will eventually return to the Main Menu.  
SCW Series Central Chilling Stations  
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Figure 6  
SCW Series Standard Control Panel  
7-2 Using the SCW Series Standard Operator  
Interface  
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7-3 Getting Started on the SCW Series Standard  
Operator Interface  
7-4 Viewing and Operating Chiller Compressors  
Viewing Compressor Status  
Operating the chiller compressors  
Setting Compressor Lead/Lag Times and Activating Compressor  
Lead/Lag Operation  
Viewing Compressor Run Times  
7-5 Viewing and Operating Chiller Pumps  
Viewing Chiller Pump Status  
Operating Chiller Pumps  
Setting Pump Lead/Lag Times and Activating Pump Lead/Lag  
Operation  
Viewing Pump Run Times  
SCW Series Central Chilling Stations  
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7-6 Viewing Active Alarms and Handling Alarm  
Conditions  
! CAUTION  
Never attempt to service a unit until a qualified  
electrician has opened and locked out the main  
disconnect using OSHA 1910.147 standards.  
All electrical connections must be done by a qualified  
electrician.  
! WARNING  
Disconnect all power to the unit, let the unit  
cool down, and turn off the water prior to any  
servicing.  
Failure to do so can result in SERIOUS INJURY  
OR DEATH!  
7-7 Viewing and Setting System Temperatures  
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Setting System Temperatures  
SCW Series Central Chilling Stations  
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Using the Advanced  
8
Touchscreen Interface  
8-1 Touchscreen Interface Introduction (MMI)  
The Advanced touchscreen interfaces let you control your SCW  
Series central chilling station. You can do such things as:  
• Control compressors and optional pumps  
• View current statuses of operation, such as pressures,  
temperatures, and capacities  
• Handle alarm conditions  
The sections in this chapter list special instructions for operating  
either touchscreen interfaces.  
Note: The screens shown in this chapter are sample screens.  
Actual screen representations may be slightly different in  
appearance, but are no different in operation. Also, the  
PLC is configured based on options and system  
configuration at the time of order. These screens are the  
basic ones to startup the chiller.  
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Figure 7  
SCW Series Advanced Control Panel  
8-2 Using the SCW Series Advanced Touchscreen  
Interface  
SCW Series Central Chilling Stations  
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8-3 Getting Started on the SCW Series Advanced  
Touchscreen Interface  
Figure 8  
Main Menu Screen  
The Main Menu screen lets you gain access to:  
• “Active Alarms” contains the current alarm(s) of the system  
• “Al;arm History” contains the last thirty (30) alarms that  
were activated.  
• “Compressor Hourmeters” contains the lifetime and  
resettable hour meters to show the number of hours that the  
compressors have been running  
• If the chiller was configured to operate the chilled water pump  
tank, there are three screens to configure and view the pump  
tank setup. The configuration screen allows for the user to turn  
on or off any of the pumps as well as configuring the lead/lag  
rotation (if multiple pumps were configured)  
• “Chiller Configuration” shows the configuration of the  
chiller itself including the chiller temperature setpoint,  
temperature alarm settings, as well as setting up the lead/lag  
rotation, and the ability to turn on and off the compressors.  
• “PanelView Utilities” and “ACS Service” are both  
password protected sections of the PLC that are used to  
configure the display and the initial configuration of the chiller  
and system.  
The following sections in this chapter list the information you need  
to navigate through these screens for operating and monitoring  
your SCW Series central chilling station with the Standard Control  
Package.  
8-4 Viewing and Operating Chiller Compressors  
Viewing Compressor Status  
To view the status of the chiller compressors, start at the Main  
Menu screen, then:  
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„ Press the Up or Down buttons on the right side of the screen to  
highlight “System Information”  
„ Press ↵  
The chiller status screen displays:  
Figure 9  
Chiller Status Screen  
The Chiller Status screen shows the status for compressors within  
the system. Only compressors that are included in the system will  
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be shown on this screen. Compressors will display one of the  
following states:  
1. OFFLINE – This indicates that the compressor has been turned  
off in the compressor enable/disable screen. The compressor  
will not be called to operate until it has been re-enabled. The  
color code for this indication is black.  
2. READY – Indicates that the compressor is enabled and ready  
to run. However, the current loading does not require the  
compressor to be running. This compressor will be  
automatically started when needed. The color code for this  
indication is yellow.  
3. RUNNING – Compressor is currently running. The color code  
for this indication is green.  
4. FAULT – A safety on the compressor indicates a fault  
condition and the compressor has been deactivated. Once the  
problem is remedied, the compressor will return to a READY  
state unless it is put in the OFFLINE state. The color code for  
this indication is red.  
Operating the chiller compressors  
To enable or disable the individual compressors, start at the Main  
Menu, then:  
„ Press the Up or Down buttons on the right side of the screen to  
highlight “Chiller Configuration”  
„ Press the ↵button  
The configuration menu screen displays:  
Figure 10  
Chiller Configuration Screen  
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„ Touch the screen corresponding with the compressor you want  
to bring On-Line or Off-Line. The background color of the  
square turns green for On-Line and black for Off-line.  
Setting Compressor Lead/Lag Times and Activating Compressor  
Lead/Lag Operation  
While in the Configuration Menu, the compressors can be setup in  
a lead/lag configuration using interval hours. By pressing the  
“Compressor Rotation Interval” button, a numeric keypad  
will be displayed and allow the user to change the timeframe of the  
interval.  
To activate the Lead/Lag operation, touch the “Compressor  
Rotation” button. The status of the button will change to Enabled  
(green background), or Disabled (black background).  
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Viewing Compressor Run Times  
From the Main Menu, use the Up or Down buttons to highlight the  
“Compressor Hourmeters” menu. Scroll to select the  
compressors. Then press ↵ to display the hourmeters.  
Note: This is a complete list of all compressors that may be  
included in the system. Any compressor that is not  
included in the system will not accumulate time.  
The Compressor Run Time screen displays:  
Figure 11  
Compressor Run Time Display Screen  
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Two hourmeters are kept for each compressor in the system. The  
first is a lifetime meter. This measures the total time that the  
compressor has been operational in the lifetime of the chiller. The  
second is a resettable hourmeter. This hourmeter can be cleared to  
monitor run time on specific intervals. In order to clear the  
resettable hourmeter, press the Hour Meter Reset button (as  
prompted on the screen)  
8-5 Viewing and Operating Chiller Pumps  
If your chiller system was configured to operate the pump(s) of the  
chilled water pump tank, the user may view the status of the  
process and recirculation pumps.  
Viewing Chiller Pump Status  
To view the status of the pumps, start from the Main Menu, then:  
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„ Press the Up or Down buttons to highlight either “System  
Information”.  
„ Press ↵  
The Pump Status Screen appears  
Figure 12  
Pump Status Screen  
Only pumps that are included in the system will be shown on this  
screen. Pumps will display one of the following states:  
1. OFFLINE – This indicates that the pump has been turned  
off in the pump enable/disable screen. The pump will not  
be called to operate until it has been re-enabled. The color  
code for this indication is black.  
2. READY – Indicates that the pump is enabled and ready to run.  
However, the current number of pumps specified to run does  
not require this pump to operate. The color code for this  
indication is yellow.  
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3. RUNNING – Pump is currently running. The color code for  
this indication is green.  
4. FAULT – A safety on the pump indicates a fault condition and  
the pump has been deactivated. Once the problem is remedied,  
the pump will return to a READY state unless it is put in the  
OFFLINE state. The color code for this indication is red.  
Operating Chiller Pumps  
To turn on and off the pumps, start from the Main Menu, then:  
„ Press the Up or Down buttons to highlight either “Chilled  
Water Pump Tank Configuration”.  
„ Press ↵  
The Pump Enables Screen appears  
Figure 13  
Pump Enables Screen  
Any pump that is disabled to the OFF-LINE position will not be  
called to operate. Simply press the button of the desired pump to  
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toggle the state of the pump from the ON-LINE to OFF-LINE  
state.  
Setting Pump Lead/Lag Times and Activating Pump Lead/Lag  
Operation  
While in the Configuration Menu, the pump lead/lag (rotation) can  
be enabled or disabled. Simply press the Process or Recirculation  
Pump Interval button on the screen to toggle between Enabled and  
Disabled.  
The interval between rotating pumps may also be setup in this  
screen. Press the CW Pump Rotation Interval button to bring up  
the time entry screen. Acceptable range is 50-200 hours.  
Viewing Pump Run Times  
From the Main Menu, use the Up or Down buttons to highlight  
either the “Chilled Water Process Pump Hourmeters” or  
“Chilled Water Recirc Pump Hourmeters” menu. Then  
press ↵ to display the hourmeters.  
Note: This is a complete list of all pumps that may be included in  
the system. Any pump that is not included in the system  
will not accumulate time.  
The Pump Run Time screen displays:  
Figure 14  
Pump Run Time Display Screen  
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Pumps:  
Pump 1  
Pump 1  
Pump 2  
Pump 2  
Two hourmeters are kept for each pump in the system. The first is  
a lifetime meter. This measures the total time that the pump has  
been operational in the lifetime of the chiller. The second is a  
resettable hourmeter. This hourmeter can be cleared to monitor  
run time on specific intervals. In order to clear the resettable  
hourmeter, press the appropriate “Hour Meter Reset” button (as  
prompted on the screen)  
8-6 Viewing Active Alarms and Handling Alarm  
Conditions  
These two screens let you view any active alarm conditions as well  
as the alarm history for the entire history. The list of system  
alarms that are tracked are as follows:  
„ Chilled Water High Temperature Alarm  
„ Chilled Water Low Temperature Alarm  
„ Compressor Motor Protector Fault (One for each compressor)  
„ Chilled Water Circuit Low Flow (One per chilled water circuit)  
„ Chilled Water Circuit Freezestat (One per chilled water circuit)  
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„ Chilled Water Circuit High Pressure (One per chilled water  
circuit)  
„ Chilled Water Circuit Low Pressure (One per chilled water  
circuit)  
„ Pump motor overload (One per system pump)  
If an alarm condition occurs, the follow screen is displayed:  
Figure 15  
Alarm Condition Screen  
To acknowledge the alarm, press the alarm silence button to clear  
it. It will then appear in the alarm history screen. Except for High  
and Low Water Temperature, and Low Refrigerant Pressure, these  
alarms are considered fatal and maintenance must be preformed in  
order to allow the chiller to fully run. Should a compressor or  
pump turn off from an alarm condition, the remaining will shut  
down and display FAULT in the status screen for the device.  
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Once a device has gone offline you will need to contact a licensed  
professional (electrician or refrigeration sevice company) to bring  
the device back online.  
! CAUTION  
Never attempt to service a unit until a qualified  
electrician has opened and locked out the main  
disconnect using OSHA 1910.147 standards.  
All electrical connections must be done by a qualified  
electrician.  
! WARNING  
Disconnect all power to the unit, let the unit  
cool down, and turn off the water prior to any  
servicing.  
Failure to do so can result in SERIOUS INJURY  
OR DEATH!  
8-7 Viewing and Setting System Temperatures  
To view the actual process temperature, start at the Main Menu and  
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„ Use the Up or Down arrows to highlight “System  
Information”  
„ Press ↵  
The system status displays:  
Figure 16  
System Status Screen  
Note: If you have a metric version of the SCW Series controller, the screens display in  
converted metric values.  
Setting System Temperatures  
The chiller setpoints are set through the compressor configuration  
menu. Starting from the Main Menu:  
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„ Press the Up or Down buttons to highlight “Chiller  
Configuration”  
„ Press ↵  
„ Touch the “Process Set-point” button  
The input display screen appears:  
Figure 17  
Temperature Input Display Screen  
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9
Routine Maintenance  
9-1 Lubrication  
Grease all fan bearings, fan motors, and pump motors that do not  
have permanently sealed bearings. Remove the grease relief plug  
(motors only) before adding grease. Failure to do so may  
dislodge the bearing grease retainer which will eventually  
cause bearing failure.  
Lubricate components regularly, based only on the component  
manufacturer’s specifications for frequency and lubricant.  
Compressors require a special scroll oil (Suniso 3GSA or  
equivalent); failure to use this oil when lubricating will void the  
warranty.  
9-2 Condenser Maintenance  
Dirty condenser heat exchange surfaces reduce system capacity.  
Inspect and clean as needed.  
Remote Air-Cooled  
Brush or vacuum light dirt accumulations. Avoid bending or  
damaging the fins. Heavy soil accumulations on the coil require  
professional steam cleaning by a qualified refrigeration service  
technician. Washing from the outside will only make matters  
worse.  
Water-Cooled  
Proper water treatment will greatly reduce cleaning intervals.  
Remove dirt in the condenser tubes with a nylon tube brush.  
Mineral deposits can be removed by circulating Sterling Liquid  
De-Scaling Solution (Sterling Model Number A0502600)  
through the water side of the condenser. Follow the directions on  
the container.  
The refrigerant side is sealed and requires no routine maintenance.  
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9-3 Evaporator Maintenance  
The evaporator(s) may be accessed for back-flushing by removal  
of the 2” plug (approx. 51 mm) in the return control nipple and the  
flow switch in the supply control nipple. If the suggested piping  
recommendations have been followed, one circuit of a multiple  
circuit chiller may be back-flushed without shutting down the  
entire system. Check Y-strainer for any clogging.  
9-4 Pump Motor Seal  
Pump seals require water for lubrication, so the pump(s) must  
never be run dry. Always fill the tank before attempting to operate  
the pump(s). Seal failures usually follow a period of dry operation  
of the pump.  
9-5 Makeup Valve  
Periodically inspect the water makeup valve assembly for proper  
operation. If the valve no longer shuts off completely or reliably,  
replace it. The plastic ball float should be buoyant for proper  
operation.  
9-6 Recommended Pump Tank Spare Parts  
Part no.  
A0550190  
A0102396  
A0069538  
A0102394  
Part description  
Pressure gauge  
Float valve, 1” (approx. 25 mm)  
Plastic ball float, 6” (approx. 152 mm)  
Float rod, 10” (25 cm)  
Quantity  
1 per pump  
1 per tank  
- Call Sterling Parts - Pump seal and casing gasket  
1 per pump  
Check your Customer Information Packet for a complete list of  
spare parts and part numbers for your SCW Series chilling station.  
SCW Series Central Chilling Stations  
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9-7 Preventive Maintenance Service  
A systematic preventive maintenance program helps avoid costly  
down time. Call the Service Department at Sterling to arrange a  
schedule of inspections. This service, described in Sterling  
Bulletin No. 10-106.3, is tailored to fit your maintenance  
requirements.  
Inspections include:  
; Check refrigerant suction and discharge pressures.  
; Check safety and operating controls.  
; Check voltage and amperage of all motors.  
; Check all electrical connections.  
; Check quantity of refrigerant.  
; Check compressor oil level.  
; Check lubrication of motor and pump bearings.  
; Check circulating pump operation.  
; Check flow through heat exchangers.  
; Check compressor efficiency.  
; Check noise levels.  
; Check cleanliness of equipment area.  
.
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10  
Troubleshooting  
Problem  
Possible Cause  
No power.  
Solution  
Check main disconnect,  
fuses, wiring, and power lead  
to unit.  
Voltage must be within plus  
or minus ten percent (±10%)  
of nameplate rating.  
Wrong voltage supplied to  
unit.  
Defective On/Off switch.  
Replace switch.  
Replace fuse, check  
transformer, check wiring for  
loose wires, check for shorted  
coils on contactors and  
solenoids, check crankcase  
heater.  
Control circuit fuse blown.  
Unit does not run.  
Defective control transformer. Replace.  
Check pump for proper  
rotation.  
Reset and test motor.  
Check that the chiller pump is  
running.  
Flow switch circuit is open.  
Pump motor off on overload.  
Unit is off on flow switch or  
pressure switch.  
Check that all valves are  
open.  
Check for defective flow  
switch or pressure switch.  
Lower freeze control setting  
to 10°F (6ºC) below the  
leaving temperature you  
want.  
Freeze control set higher than  
temperature of liquid in  
system.  
Air cooled units: Check and  
clean air filters. Check  
condenser fans for proper  
rotation. Check for dirty  
condenser. Check for  
condenser air obstruction.  
Check for tripped motor  
overload, blown fuses, or bad  
condenser fan motor.  
Water cooled units: Check for  
water valves turned on.  
Check for dirty condenser.  
Check water flow through  
condenser.  
Pump runs,  
compressor does not.  
High pressure refrigerant  
cutout switch contacts open.  
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Problem  
Possible Cause  
Solution  
Allow time to cool and reset.  
Check for high/low voltage.  
Voltage must be within plus  
or minus ten percent (±10%)  
of nameplate rating.  
Compressor internal overload  
open.  
Check for poor compressor  
electrical connections.  
Check compressor rotation  
on scroll compressors.  
Compressor contactor  
holding coil open.  
Repair or replace.  
Pump runs,  
Defective fan motor.  
Fan motor out on overload.  
Defective freezestat.  
Refrigerant low.  
Repair or replace.  
Reset and test.  
Replace.  
Check the refrigerant charge.  
Replace.  
compressor does not  
(cont’d).  
Defective fan cycling control.  
Sight glass should be clear  
while comperssor runs. Call  
for service if bubbling or  
foaming.  
Low refrigerant pressure  
switch contact open.  
Defective pump motor  
interlock to compressor  
control circuit.  
Repair or replace.  
Broken wire in the  
compressor control circuit.  
Locate and repair.  
Lower set point to 10°F (6ºC)  
below the leaving water  
temperature you want with at  
least 15 degrees differential.  
Check refrigeration charge;  
check refrigerant sight glass  
for bubbles or a level in the  
glass.  
Freezestat control setting is  
too high.  
Pump runs, compressor  
cycles at short intervals.  
Refrigerant is too low.  
Be sure the antifreeze  
mixture protection is right for  
the process.  
Improper water/glycol  
mixture.  
Leaving water temperature is  
not at set point.  
Defective freezestat control.  
Refrigerant charge is low.  
Replace.  
Call service to find and repair  
the leak. Add refrigerant.  
Check for partially closed  
valves etc. Be sure all lines  
are properly sized.  
Pump pressure is too high.  
Restricted water flow.  
SCW Series Central Chilling Stations  
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Problem  
Possible Cause  
Solution  
Verify proper rotation; if  
incorrect, see Changing  
Rotation Direction on Page  
25 for more information.  
Clean the system. You may  
also have to pull the pump  
and inspect the impeller.  
Check for foam in the water  
circuit; add anti-foam if  
needed.  
Isolate evaporator, thaw out,  
check for leaks. Check  
coolant solution. Coolant  
solution should be good for at  
least 10ºF (6ºC) below  
leaving water temperature.  
Clean air filters, clean  
condenser, check water flow.  
Check superheat on  
expansion valve.  
Pump is running in reverse.  
Pump pressure is too low.  
Check for foreign matter.  
Evaporator frozen.  
Process water pressure low,  
pressure at pump high.  
Restricted condenser air flow.  
Refrigerant not feeding.  
Make sure that coolant  
mixture protection is right for  
the process.  
Backflush and clean  
evaporator.  
Improper water/glycol  
solution.  
Unit runs continuously, but  
not enough cooling  
power.  
Poor heat transfer in  
evaporator.  
Unit low on refrigerant.  
Low water flow through  
evaporator.  
Call service.  
Increase flow to design flow  
of 2.4 gpm/ton.  
Inefficient compressor.  
Unit under-sized for  
application.  
Call service.  
Call sales representative.  
.
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Service Notes  
SCW Series Central Chilling Stations  
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I
Index  
Water Treatment  
Condenser Water Manifold,  
32  
Control Nipple, 32  
Control Probe, 32  
Considerations, 24  
Water-Cooled Condenser  
Connections, 24  
Alarms  
Advanced Controls, 59  
Standard Controls, 46  
Available options, 10  
Flow Switch, 31  
Freezestat Control, 29  
High Pressure Cutout, 31  
Lead-lag Compressors, 28  
Lead-Lag Pumps, 28  
Low Pressure Cutout, 31  
Refrigeration Circuit, 29  
Shipping damages, 16  
Shipping information, 16–18  
Incomplete shipment, 17  
Incorrect shipment, 17  
Returns, 17  
Location considerations, 20  
Checking Motor Direction, 26  
Chiller Pumps  
Makeup Valve Maintenance, 65  
Models covered, 9  
Motors  
Advanced Controls, 55  
Chiller Shutdown, 40  
Circuit Alarm Sequence, 28  
Compressor Lead-Lag, 28  
Compressor Staging  
Sequence, 28, 32  
Checking Direction, 26  
Necessary documents, 8–9  
Condenser Maintenance, 64  
Copyright information, 2  
Operating Compressors  
Advanced Controls, 50  
Standard Controls, 45  
Options, 10  
Shipping damages, 16  
Uncrating, 18  
Unpacking and inspection,  
16  
Determining Flow Rate, 40  
Disclaimer information, 2  
Piping Considerations, 22  
Process Water Connections,  
22  
Pump Lead-Lag, 28  
Pump Seal Maintenance, 65  
Pump Tank Piping  
Connections, 23  
Specifications  
Electrical connections, 20  
Electrical wiring schematics, 21  
Evaporator Maintenance, 65  
RCR, 14  
RSR Condensers, 15  
RSW, 12, 13  
Standard Controls  
Touchscreen, 44, 49  
Standard features, 9–10  
Startup Checklist, 34–40  
Chiller Shutdown, 40  
Determining Flow Rate, 40  
Introduction, 34  
Freezestat Control, 29  
Galvanic Corrosion  
Considerations, 24  
General information  
RCR specifications, 14  
Remote Air-Cooled Condenser  
Installation, 25  
Remote Air-Cooled Startup, 39  
Remote Air-Cooled Startup  
Checklist, 37  
Return material authorization  
number (RMA), 16  
Returns, 17  
Available options, 10  
Models covered, 9  
Remote Air-Cooled, 37  
Remote Air-Cooled Startup,  
39  
Necessary documents, 8–9  
Standard features, 9  
Graphic Panel Devices, 41  
Indicator Lights and  
Control Switches, 41  
Water Cooled, 34  
Water Cooled Startup, 36  
System Temperatures  
Advanced Controls, 61  
RMA number, 16  
Routine Maintenance, 64–66  
Condensers, 64  
Incomplete shipment, 17  
Incorrect shipment, 17  
Installation information, 20–27  
Checking Motor Direction,  
26  
Troubleshooting, 64–66  
Evaporators, 65  
Lubrication, 64  
Makeup Valve, 65  
Pump Seals, 65  
Uncrating, 18  
Unpacking and inspection, 16  
Using the Advanced  
Touchscreen Interface, 48–  
63  
Connection Sizing  
RSR Condenser Specifications,  
15  
RSR drawing, 14  
RSW drawing, 12  
RSW specifications, 12, 13  
Considerations, 24  
Electrical connections, 20  
Galvanic Corrosion  
Considerations, 24  
Location considerations, 20  
Piping Considerations, 22  
Process Water  
Connections, 22  
Remote Air-Cooled  
Condensers, 25  
Alarms, 59  
Chiller Pumps, 55  
Getting Started, 50  
Introduction, 48  
Safety considerations, 3  
Sequence of Operation, 27–32  
Alarms, 28  
Operating Chiller  
Compressors, 50  
System Temperatures, 61  
Using the Standard  
Touchscreen Interface, 44,  
43–47, 49  
Chilled Water Circuit, 29  
Chilled Water Manifold, 32  
Compressor Staging, 28  
Tank Piping Connections,  
23  
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Alarms, 46  
Water Cooled Startup  
Checklist, 34  
Water Treatment  
Considerations, 24  
Water-Cooled Condenser  
Connections, 24  
Getting Started, 45  
Introduction, 43  
Operating Chiller  
Compressors, 45  
Water Connection Sizing  
Consideration, 24  
Water Cooled Startup, 36  
SCW Series Central Chilling Stations  
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Service Notes  
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Service Notes  
SCW Series Central Chilling Stations  
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Service Notes  
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Technical Assistance  
Parts Department  
[800]  
Call toll-free 7am–5pm CST or call  
423-3183, [262] 641-8610, or fax to [262] 641-8653  
The ACS Customer Service Group will provide your company with genuine OEM quality parts  
manufactured to engineering design specifications, which will maximize your equipment’s performance  
and efficiency. To assist in expediting your phone or fax order, please have the model and serial  
number of your unit when you contact us. A customer replacement parts list is included in this manual  
for your convenience. ACS welcomes inquiries on all your parts needs and is dedicated to providing  
excellent customer service.  
Service Department  
[
]
[262]  
Call toll-free 8am–5pm CST 800 423-3183 or call 641-8610  
[
]
Emergencies after 5pm CST, call 847 439-5655  
We have a qualified service department ready to help. Service contracts are available for most of our  
products. www.acscustomerservice.com  
Sales Department  
[262]  
Call  
641-8610 Monday–Friday, 8am–5pm CST, fax [262] 641-8653  
Our products are sold by a world-wide network of independent sales representatives. Contact our Sales  
Department for the name of the sales representative nearest you.  
Contract Department  
[262]  
Call  
641-8610 Monday–Friday, 8am–5pm CST  
Let us install your system. The Contract Department offers any or all of these services: project planning;  
system packages including drawings; equipment, labor, and construction materials; and union or non-  
union installations.  
Sterling, Inc.  
2900 S. 160th Street  
New Berlin, WI 53151  
www.sterlco.com  
SCW Series Central Chilling Stations  
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