PART #459657
READ AND SAVE THESE INSTRUCTIONS
ENERGY RECOVERY UNIT
with HEATING
®
Models:
ERH-20, 45, 55, & 90
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
**WARNING**
DISCONNECT AND SECURE TO THE "OFF"
Energy Recovery Wheel
POSITION ALL ELECTRICAL POWER TO THE
UNITS PRIOR TO INSPECTION OR SERVICING.
FAILURE TO COMPLY WITH THIS SAFETY
PRECAUTION COULD RESULT IN SERIOUS
INJURY OR DEATH.
**IMPORTANT**
ALL FACTORY PROVIDED LIFTING LUGS MUST
BE USED WHEN LIFTING THE UNITS. FAILURE
TO COMPLY WITH THIS SAFETY PRECAUTION
COULD RESULT IN PROPERTY DAMAGE,
SERIOUS INJURY OR DEATH.
INSTALLATION SUPPLEMENT
Refer to the following Greenheck installation
supplement for ERH units supplied with Indirect
Gas (IG) heating:
Model PVF, Indirect Gas Fired Furnaces for
Energy Recovery Units, Part #461006
Heating Section
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BASIC OPERATION
The ERH brings in fresh,
outdoor air and
Energy
Recovery
Wheel
Exhaust Air
from building
removes stale, exhaust
air. Prior to discharging
the exhaust air, the
energy recovery wheel
transfers energy from
the exhaust air to the
outdoor air at an
Exhaust Air
discharged outside
efficiency of 70-80%.
Simply put, this unit
preconditions the
Outdoor Air
outdoor air to save
money on heating and
cooling costs. This
particular unit also has
a heater option
Optional
Heater
available after the
recovery wheel to
further increase the
fresh air temperature if
desired.
Preconditioned Air sent
to conditioning system
INSTALLATION
Lift using lifting
lugs and
spreader bar
The system design and installation should follow accepted industry
practice, such as described in the ASHRAE Handbook.
Adequate space should be left around the unit for piping coils and
drains, filter replacement, and maintenance. Sufficient space should
be provided on the side of the unit for routine service and
component removal should that become necessary.
See page 6 for more detail on appropriate clearances.
LIFTING
Units must be lifted as it ships from the factory. All units are
equipped with lifting lugs. THE USE OF ALL LIFTING LUGS IS
MANDATORY WHEN LIFTING. Lifting should only be done with all
access doors closed to avoid damaging the unit. To prevent damage
to the unit cabinetry, use spreader bars. Spreader bars must be in
position to stop cables from rubbing the frame or panels. Before
hoisting into position, test lift to insure stability and balance. Avoid
twisting or uneven lifting of the unit. Never lift units by weatherhoods.
FIGURE 1
RECOMMENDED ROOF OPENING
UNIT WEIGHTS (dry weights)
V
TABLE 2
TABLE 1
Unit Size Approx. Weight (lbs)
Model
U
V
EXHAUST
INLET
ERH-20
ERH-45
ERH-55
ERH-90
1000
1800
2500
4500
ERH-20
ERH-45
ERH-55
ERH-90
46
54
65
85
37
39
47
49
U
SUPPLY
OUTLET
Dimensions shown are in inches.
FIGURE 2
3
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ROOF CURB MOUNTING
1. Factory Supplied Roof Curbs
Roof curbs are Model GKD, which are shipped in a
knockdown kit and require field assembly (by
others). Assembly instructions are included with
the curb.
2. Cut Roof Opening and Locate Curb
Layout the unit roof opening such that the supply
discharge & exhaust inlet of the unit will line up
with the corresponding ductwork (refer to
Recommended Roof Openings on page 3). Be
sure to allow for the recommended service
clearances. Keep the supply inlet of the unit away
from any other exhaust fans.
3. Install Curb
Locate curb over roof opening and fasten in place.
Check that the diagonal dimensions are within
1/8 inch of each other and adjust as necessary.
Shim as required to level. Lower unit onto curb by
following the LIFTING instructions on page 3 of
this manual. Note,
TABLE 3
roof curbs fit inside
L
the unit base.
Curb Outside Dimensions
W
Model
L
W
4. Install Duct Work
Installation of all
FIGURE 3
ERH-20
ERH-45
ERH-55
ERH-90
73
80.75
94
51
ducts should be
60.63
71.5
done in accordance
with SMACNA and
AMCA guidelines.
Roof curb details, including duct
location dimensions, are available
on ERH roof curb submittals.
106.25 90.75
Dimensions shown are in inches.
DUCT WORK CONNECTIONS
Examples of good and poor fan-to-duct connections are shown below (See FIGURE 4). Airflow out of the fan
should be directed straight or curve the same direction as the fan wheel rotates. Poor duct installation will result
in low airflow and other system effects.
n
o
i
t
n
o
i
t
Length of Straight Duct
a
t
a
t
o
o
R
R
GOOD
POOR
FIGURE 4
Recommended Discharge
Duct Size and Length
TABLE 4
ERH
Blower
Size
Straight
Duct
Length
ERH
Model
Duct
Size
20
45
55
90
10
12
15
18
14 x 14
20 x 20
28 x 28
32 x 32
40
48
60
72
Dimensions shown are in inches.
4
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INSTALLATION (continued)
WEATHERHOODS
Supply weatherhood will be factory mounted. The exhaust weatherhood is shipped separately as a kit with its
own instructions.
EXHAUST DAMPERS
Backdraft dampers for exhaust discharge are mounted in the unit. Motorized dampers are shipped loose (inside
ERH) and must be field installed.
ELECTRICAL CONNECTIONS
The electrical supply must be compatible with that shown on the nameplate: voltage, phase, and amperage
capacity. The electrical supply line must be properly fused and conform to local and national electrical codes.
All internal electrical components are pre-wired at the factory. Field electrical connections only need to be made
inside the unit to the main disconnect (See FIGURE 5, Item #1) and the 24 volt control circuit (See FIGURE 5,
Item #7). A door interlocking safety disconnect is provided as standard feature.
Note: Standard factory installed electric post heaters have their own disconnect separate from the unit
disconnect. Thus, electric post heaters require a separate power connection.
IMPORTANT:
Use minimum 14 ga. wire for 24 volt control power.
Control wire resistance should not exceed 0.75 ohms (approximately 285 feet total length for
14 ga. wire; 455 feet total length for 12 ga. wire). If wire resistance exceeds 0.75 ohms, an
industrial-style, plug-in relay should be added to the unit control center and wired in place of
the remote switch (between terminal blocks 2 and 3 on the control strip — See FIGURE 5,
Item #7). The relay must be rated for at least 5 amps and have a 24 Vac coil. Failure to
comply with these guidelines may cause motor starters to “chatter” or not pull in which can
cause contactor failures and/or motor failures.
TYPICAL CONTROL CENTER COMPONENTS
1. Main Disconnect
2. Motor Starter — Exhaust/Scavenger
Air Fan
3. Motor Starter — Outdoor Air Fan
4. Motor Contactor — Energy Wheel
5. Control Power Transformer
(24 VAC Secondary)
6. Energy Wheel Motor Transformer
(230 VAC Secondary)
(for ERH-20 & ERH-45 units with
primary voltage greater than 230 Vac)
7. 24 VAC Terminal strip
1
8
5
6
8. Fuses for the control circuit, wheel
drive transformer, and blower
motors.
7
4
Control Center
O
f
f
On
3
2
Main
Disconnect
Intake
Hood
FIGURE 5
Exhaust
Hood
5
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SERVICE CLEARANCES / ACCESS PANEL LOCATIONS for Model ERH
ERH-20, 45, 55, and 90 units require minimum clearances for access on all sides for routine maintenance. Filter
replacement, drain pan inspection and cleaning, energy wheel cassette inspection, fan bearing lubrication and
belt adjustment, are examples of routine maintenance that must be performed. Blower and motor assemblies,
energy recovery wheel cassette, coil and filter sections are always provided with a service door or panel for
proper component access. Clearances for component removal may be greater than the service clearances,
refer to FIGURES 6 and 7 below for these dimensions.
Clearances for service and component removal on ERH-20 and ERH-45
36 in.
Exhaust
Hood
Access Panel
Electrical Box
36 in.
0 in.
Exhaust Air
Intake
Clearance without
IG Heater
52 in.
Clearance with
IG Heater
Access Panel
*48 in. **64 in.
TOP VIEW
*Clearance for energy wheel removal on ERH-20.
**Clearance for energy wheel removal on ERH-45.
FIGURE 6
Clearances for service on ERH-55 and ERH-90
42 in.
Exhaust
Hood
Access Panel
Electrical Box
42 in.
0 in.
Exhaust Air
Intake
Clearance without
IG Heater
52 in.
Clearance with
IG Heater
Access Panel
42 in.
TOP VIEW
FIGURE 7
6
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WATER COIL LOCATION AND CONNECTION
A hot water coil can be factory installed in the coil section of the ERH. The coil section is downstream of the
energy wheel on the supply air side of the unit. Coil connections are external to the unit as shown below. Coil
connections not external have been ordered from the factory with internal or exhaust air stream connections.
FIGURE 9
FIGURE 10
TABLE 5
Model
ERH-90 Coil
Connections
A
B
C
D
D
ERH-20
15
33 3⁄4
39 1⁄4
48 1⁄4
54 1⁄4
41 1⁄4
46 3⁄4
46 3⁄4
50 1⁄2
1 1⁄2 NPT
1 1⁄2 NPT
2 NPT
ERH-45L 17 1⁄2
ERH-45H 17 1⁄2
Top
Coil
303⁄4
ERH-55
ERH-90
17 1⁄2
2 NPT
1 1⁄2 NPT
17 1⁄2 See Note 5 62 1⁄4
Note 1: Dimensions shown are for 1-row coil.
Note 2: All dimensions are in inches (measured
to center of coil connections).
B
63⁄4
Note 3: NPT - National Pipe Thread.
Note 4: ‘A’ dimension assumes a 12 in. curb.
Note 5: The ERH-90 uses a dual coil (stacked
on top of each other). Refer to FIGURE
10 for the ‘B’ dimension.
Bottom
Coil
303⁄4
C
A
WATER COIL APPLICATION
RECOMMENDATIONS
Factory installed heating components are mounted
down stream of the energy wheel on the supply air side
of the unit.
DX coil liquid
connection
access door
See FIGURE 8 & 9 for coil connection location. Coil
connections are located external to the unit as shown.
Coil connections that are not external have been ordered
from the factory with interior or exhaust air stream coil
connections.
Water coil
connections
1. Piping should be in accordance with accepted
industry standards. Pipework should be supported
independently of the coils. Water connections are
male NPT iron pipe. When installing couplings, do
not apply undue stress to the connection
extending through the unit. Use a backup pipe
wrench to avoid breaking the weld between coil
connection and header.
FIGURE 8
4. Water coils are not normally recommended for use
with entering air temperatures below 40oF;
however, the energy recovery wheel maintains a
pre-coil temperature higher than 40oF. No control
system can be depended on to be 100% safe
against freeze-up with water coils. Glycol
solutions or brines are the only safe media for
operation of water coils with low entering air
conditions.
2. Connect the WATER SUPPLY TO THE BOTTOM
CONNECTION on the air leaving side and the
WATER RETURN TO THE TOP CONNECTION on
the air entering side. To insure proper venting, an
external air vent in the piping is recommended.
Connecting the supply and/or return in any other
manner will result in very poor performance. Be
sure to replace factory installed grommets around
coil connections if removed for piping. Failure to
replace grommets will result in water leakage into
the unit and altered performance.
CONTINUOUS WATER CIRCULATION THROUGH
THE COIL AT ALL TIMES IS HIGHLY
RECOMMENDED.
5. Pipe sizes for the system must be selected on the
basis of the head (pressure) available from the
circulation pump. The velocity should not exceed
6 feet per second and the friction loss should be
approximately 3 feet of water column per 100 feet
of pipe.
3. The air vent at the uppermost point should be
temporarily opened during system start-up to
release all of the air from the coil. To maintain heat
transfer capacity, periodically vent any air in coil.
7
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ELECTRIC HEATER APPLICATION/OPERATION
Factory installed electric heaters can be provided for preheat and/or post-heat (see FIGURE 11). An electric
preheater warms the outdoor air prior to the energy recovery wheel to prevent frosting on the wheel. An electric
post-heater warms the air leaving the energy recovery wheel to a user specified discharge temperature. Electric
heaters are available in 208, 230, or 460 Vac (refer to heater nameplate for voltage).
Preheaters:
Preheaters are standard as 2-stage, step control. Step control heaters are designed with
multiple stages made up of equal increments of heating capability. For example, a 10 kW
heater with two stages will be composed of two 5-kW stages. Preheaters are single point
wired at the factory. A temperature sensor (with field adjustable set point) is mounted in the
outdoor airstream after the preheater to turn the preheater on. See FROST CONTROL
APPLICATION/OPERATION for typical set points. If the outdoor air temperature falls below the
set point, the first stage of the preheater will turn on. If the first stage does not satisfy the set
point, the second stage will also turn on.
Post-heaters: Post-heaters are standard as 4-stage, step control. Post-heaters are not single point wired
(see ELECTRICAL CONNECTIONS, page 5). The functionality of a 4-stage heater is the same
as the 2-stage preheater above, except it has an additional two stages of heat control.
Post-heaters supplied with Greenheck temperature control package are 3-stage with binary
control that provides 7 steps of heating. For example, a 35 kW heater with three stages will be
composed of 5, 10, and 20 kW stages. The stages essentially ‘mix and match’ to provide heat
output from 5 kW to 35 kW, in 5 kW increments.
FIGURE 11
Electric Post-Heater
The post-heater is not single
point wired to the ERH control
center (requires separate
power). The post-heater and the
ERH each have their own
disconnect located in the UNIT
control center.
If required, access to the post-
heater control panel is through
the exhaust filter door.
Electric Preheater
The preheater is single point wired to the ERH control
center (does not require separate power). Access to the
preheater control panel is through the supply filter door.
8
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FROST CONTROL APPLICATION/OPERATION
When outdoor air temperatures are extremely cold, moisture condensation and frosting on the energy recovery
wheel is possible. Frost control is an optional feature that will prevent wheel frosting. Two options are available:
1) Timed Exhaust frost control and
2) Preheat frost control
Timed exhaust frost control includes a thermostat (with
probe) mounted in the supply air inlet compartment (see
FIGURE 13, page 10) and a timer (Figure 12) mounted in the
ERH control center. The thermostat will turn on the timed
exhaust frost control feature at a predetermined field
adjustable outdoor air temperature (referred to as the Frost
Threshold temperature). The typical temperature setting
TABLE 6
Indoor RH @ 70°F
Frost Threshold Temp
20%
30%
40%
-10°F
-5°F
0°F
corresponds to the indoor air relative humidity as shown in TABLE 6.
Testing (refer to FIGURE 12)
• Set the Timer Scale for T1 and T2 to 1 minute. Set
the Timer Settings for T1 and T2 to 1.0. Set the dip
switch to the down position.
• Turn the temperature sensor up as high as possible.
The supply blower should cycle on for one minute,
then turn off for one minute.
A1
B1
15
0.8 0.6
1.0 0.4
0.2
Dip
Switch
0
• After testing, set the Timer Scale as follows: T1 = 10
minutes, T2 = 1 hour
T2
1 MIN T2
• Set the Timer Settings as follows: T1 = 0.5, T2 =
0.5. The timer is now set for 5 minutes off and 30
minutes on.
Timer
Scale
1 MIN T1
0.8 0.6
1.0 0.4
0.2
0
Preheat frost control (see FIGURE 11, page 8) includes a
thermostat (with probe) and an electric heater located in the
supply air inlet compartment and an air pressure switch in the
supply air outlet compartment. The thermostat should be set
according to the Frost Threshold temperatures shown in TABLE 6.
When the outdoor air temperature reaches the thermostat setting,
the electric preheater will turn on and warm the air entering the energy
wheel.
T1
16
18
A2
FIGURE 12
Testing
• Turn the thermostat as high as it will go. The heater should turn on.
• If it doesn’t, either put the supply side doors on or temporarily jumper the
air pressure switch to avoid nuisance tripping of the pressure switch.
Remember to remove the jumper.
DIRTY FILTER SWITCH SETUP
This unit may be equipped with a dirty filter switch that functions on differential air pressures to close a relay
when the unit filters are clogged and need cleaning. This switch has not been set at the factory due to external
system losses that will affect the switch. This switch will need minor field adjustments after the unit has been
installed with all ductwork complete. The dirty filter switch is mounted in the exhaust inlet compartment next to
the electrical control center.
To adjust the switch the unit must be running with all of the access doors in place, except for the compartment
where the switch is located (exhaust inlet compartment). Remove the switch cover plate. The adjusting screw is
located on the top of the switch. Open the filter compartment and place a sheet of plastic or cardboard over
50% of the filter media. Replace the filter compartment door. Check to see if there is power at the alert signal
leads (refer to electrical diagram). If there is no power, turn the adjustment screw on the dirty filter gage
clockwise until you have power. Open the filter compartment and remove the obstructing material. Replace the
door and check to make sure that you do not have power at the alert signal leads. The unit is now ready for
operation.
9
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ECONOMIZER APPLICATION/OPERATION
The energy recovery wheel may be de-energized for the purpose of providing economizer (free cooling)
operation. This can be achieved with a signal from a Temperature or Enthalpy sensor mounted in the supply air
inlet compartment (see FIGURE 13). This Primary sensor will de-energize the energy wheel when the outdoor air
temperature (factory default is 65°F) or enthalpy (factory default is the ‘D’ setting) is below the field adjustable
set point. An additional Override temperature sensor is also furnished in the supply air inlet compartment to
deactivate economizer mode (see FIGURE 13). The Override (with field adjustable set point) is set at some
temperature lower than the Primary sensor (factory default is 50°F). Effectively, the two sensors create a
deadband where the energy recovery wheel will not operate and free cooling from outside can be brought into
the building unconditioned.
Testing (terminals referenced below are in the unit control center — see FIGURE 5, Item #7)
Temperature sensor with Override
• Turn both Temperature and Override
thermostats down as low as they go.
The wheel should be rotating.
FIGURE 13
• Turn the Temperature sensor up as
high as it goes, and keep the Override
sensor as low as it will go. The wheel
should stop rotating.
• Turn both sensors as high as they will
Enthalpy Sensor
(Primary Sensor)
go. The wheel should start rotating.
• Set the Temperature sensor to the
desired temperature for economizer
Timed Exhaust
Override
Frost Control
operation to begin. Set the Override
sensor to the desired temperature for
economizer operation to end (factory
default is 65°F and 50°F, respectively).
Probes
Enthalpy sensor with Override
• A factory-installed 620 ohm resistor is
connected across terminals SR and +.
The Override sensor should be turned
down below current temperature in unit. Turn the unit on; LED on the sensor should be off. Check
continuity across terminals 2 and 3, there should not be continuity. There should be continuity
between terminals 1 and 2.
• Disconnect the 620 ohm resistor from terminals SR and +. LED should turn on. There should be
continuity between terminals 2 and 3. There should not be continuity between terminals 1 and 2.
• Turn the Override sensor above current temperature in unit. There should be continuity between
terminals 3 and 6. Set the Override sensor to the desired temperature for economizer operation to end
(factory default is 50°F).
• Reconnect the factory-installed jumper.
10
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START UP CHECKS
**WARNING**
DO NOT OPERATE ENERGY RECOVERY VENTILATOR WITHOUT THE FILTERS AND BIRDSCREENS INSTALLED.
THEY PREVENT THE ENTRY OF FOREIGN OBJECTS SUCH AS LEAVES, BIRDS, ETC.
DO NOT REMOVE ACCESS PANELS OR OTHER UNIT COMPONENTS WHILE STANDING ON A LADDER OR OTHER
UNSTEADY BASE. ACCESS PANELS AND UNIT COMPONENTS ARE HEAVY AND SERIOUS INJURY MAY OCCUR.
CAUTION: See **WARNING** on page 1 and above
For proper unit function and safety, follow everything in this start-up procedure in the order presented. This to
be done after the electrical and gas connections are complete.
Pre-Start Check List
1. Disconnect and lock-out all power switches to fan.
2. Check all fasteners, set screws and locking collars on the fan, bearings, drive, motor base and
accessories for tightness.
3. Rotate the fan wheel by hand and assure no parts are rubbing.
4. Check the V-belt drive for proper alignment and tension.
Special Tools Required
• Voltage meter
• Incline manometer or equivalent
• Tachometer
• Thermometer
• Amperage meter
GENERAL
Check all fasteners and set screws for tightness. This is especially important
for bearings and fan wheels. Also, if dampers are not motorized, check that
they open and close without binding.
n
o
i
t
Airflow
a
t
o
R
FAN WHEEL ROTATION
Hand rotate the blower to ensure that the wheel is not rubbing against the
scroll. If the blower is rotating in the wrong direction, the unit will move some
air but not perform properly.
FIGURE 14
To check the rotation, open the blower access panels, which are labeled either
supply or exhaust, and run the blower momentarily to determine the rotation.
Rotation should be in the same direction as airflow at the outlet (See FIGURES
14 & 15). Check for unusual noise, vibration or overheating of bearings. Refer to
the “Trouble Shooting” section of this manual if a problem develops.
To reverse the rotation, turn the power off and use the following procedure:
• For single phase units, rewire the motor per the instructions on the
motor.
FIGURE 15
• For three phase units, interchange any two power leads. (this can be
done at the motor starter).
11
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Check pulleys and belts for proper alignment to avoid unnecessary
belt wear, noise, vibration and power loss. Motor and drive shafts
must be parallel and pulleys in line (see FIGURE 16).
FAN RPM
The adjustable motor pulley is preset at the factory to the
customer specified RPM. Fan speed can be increased or
decreased by adjusting the pitch diameter of the motor pulley.
Multi-groove variable pitch pulleys must be adjusted an equal
number of turns open or closed. Any increase in fan speed
represents a substantial increase in load on the motor. Always
check the motor amperage reading and compare it to the
amperage rating shown on the motor nameplate when changing
fan RPM. Access these components through the labeled access
panels.
WRONG
WRONG
All access doors must be installed except the control center door.
To measure the fan rpm, the blower door will need to be removed.
Minimize measurement time because the motor may overamp with
the door removed. Do not operate units with access doors/panels
open or without proper ductwork in place as the motors will
overload.
WRONG
CORRECT
FIGURE 16
ENERGY RECOVERY WHEEL
CAUTION: See **WARNING** on page 1 and 11
For the ERH-20 and ERH-45, open the access door marked
"Energy Wheel Cassette Access". UNPLUG the wheel drive
motor and remove the metal spacer. Then pull the cassette
out halfway as seen in FIGURE 17.
Note: For the ERH-55 and ERH-90, the energy recovery
wheel does not slide out due to its size and weight. There is
ample room inside the unit to perform energy recovery wheel
servicing.
Turn the energy recovery wheel by hand to verify free
operation. Check that the air seals, located around the
outside of the wheel and across the center (both sides of
wheel), are secure and in good condition. Replace cassette
into unit, plug in wheel drive, replace access door and apply
power. Observe that the standard and high flow wheel
rotates freely at about 60 RPM.
FIGURE 17
If wheel does not rotate or rotates too slowly, remove the
cassette (following the instruction on page 16). Air seals, which are too tight, will prevent proper rotation of the
energy recovery wheel. Recheck the air seals for tightness. Air seal clearance may be checked by placing a
sheet of paper, to act as a feeler gauge, against the wheel face. To adjust the air seals, loosen all eight seal
retaining screws. These screws are located on the bearing support that spans the length of the cassette
through the wheel center. Tighten the screws so the air seals tug slightly on the sheet of paper.
COILS
Leak test thermal system to insure tight connections.
12
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ROUTINE MAINTENANCE
CAUTION: See **WARNING** on Page 1 and 11
Once the unit has been put into operation, a periodic maintenance program should be set up to preserve the
reliability and performance. Items to be included in this program are:
• BELTS
• MOTORS
• WHEEL AND FASTENERS
• VIBRATION
• FILTER MAINTENANCE
• COIL MAINTENANCE
• ENERGY WHEEL CASSETTE
FAN BELTS
Belt Span
Belts tend to stretch after a period of time. They should be
periodically checked for tension and wear. When replacing
belts, use the same type as supplied with the unit.
Replacement of belts should be accomplished by loosening
the motor slide plate so the belts may be removed by hand.
Do not force belts on or off as this may cause breakage of
cords and lead to premature belt failure.
Belt tension should be adjusted to allow 1/64 in. of belt
deflection per 1 in. of belt span. For example, a 16 in. belt
span should have 16/64 in. or 1/4 in. of deflection with
moderate thumb pressure at mid-point between the pulleys
(FIGURE 18).
Belt Span
Deflection =
64
FIGURE 18
MOTORS
Motor maintenance is generally limited to cleaning and lubrication (where applicable). Cleaning should be
limited to exterior surfaces only. Removing dust and grease build-up on the motor housing assures proper
motor cooling. Use caution and do not allow water or solvents to enter the motor or bearings. Under no
circumstances should motors or bearings be sprayed with steam, water or solvents.
Greasing of motors is intended only when fittings are provided. Many fractional horsepower motors are
permanently lubricated for life and require no further lubrication. Motors supplied with grease fittings should
be greased in accordance with the manufacturer’s recommendations.
WHEEL AND FASTENERS
Wheels require very little attention when moving clean air. Occasionally oil and dust may accumulate on the
wheel causing imbalance. When this occurs the wheel and housing should be cleaned to assure smooth and
safe operation. Inspect fan impeller and housing for fatigue, corrosion or wear.
Routinely check all fasteners, set screws and locking collars on the fan, bearings, drive, motor base and
accessories for tightness. A proper maintenance program will help preserve the performance and reliability
designed into the fan.
13
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VIBRATION
Excessive vibration maybe experienced during initial start-up. Left unchecked, excessive vibration can cause a
multitude of problems, including structural and/or component failure. The most common sources of vibration
are listed below.
Many of these conditions can be discovered by careful observation.
1. Wheel Unbalance
Refer to the troubleshooting section of this manual for corrective actions.
2. Drive Pulley Misalignment
If observation cannot locate the source of vibration, a qualified
technician using vibration analysis equipment should be consulted. If the
problem is wheel unbalance, in-place balancing can be done providing
there is access to the fan wheel.
3. Incorrect Belt Tension
4. Bearing Misalignment
5. Mechanical Looseness
6. Faulty Belts
7. Drive Component Unbalance
8. Poor Inlet/Outlet Conditions
9. Foundation Stiffness
Generally, fan vibration and noise are transmitted to other parts of the
building by the ductwork. To eliminate this undesirable effect, the use of
heavy canvas connectors is recommended.
EXTERNAL FILTER MAINTENANCE
Aluminum mesh 2 in. filters are located in the
supply weatherhood (if the weatherhood option
was purchased). Filters should be checked and
cleaned on a regular basis for best efficiency. The
frequency of cleaning depends upon the
cleanliness of the incoming air.
FIGURE 19
To remove these filters, remove bottom bolt in the
access door on the side of the weatherhood. Slide
the access door up and then pull out. Then, slide
the filters out (see FIGURE 19).
Clean filters by rinsing with a mild detergent in
warm water. After the filters are dry, an adhesive
spray available at most filter distributors may be
applied to increase filter efficiency.
TABLE 7
Internal
Quantity
Filter Size
Model
INTERNAL FILTER MAINTENANCE
Opening the access doors labeled as “Filter
Access” provides access to the pleated 30%
filters (if the filter option was purchased). These
filters should be checked regularly, cleaned or
replaced as needed. See TABLE 7 for pleated filter
size and quantity for each unit.
ERH-20
ERH-45
ERH-55
ERH-90
20 x 20
20 x 25
16 x 25
20 x 20
2
3
6
8
14
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WATER COIL MAINTENANCE
CAUTION: See **WARNING** on Page 1 and 11
FILTERS
Filters upstream of the coil should be checked regularly. If the filters are dirty, they should be cleaned or
replaced. It is important that the coils stay clean to maintain desired airflow. See page 14 for more information
on filter maintenance.
COIL MAINTENANCE
1. Coils must be clean to obtain maximum performance. Check once a year under normal operating
conditions and, if dirty, brush or vacuum clean. Soiled fins reduce the capacity of the coil, demand more
energy from the fan, and create an environment for odor and bacteria to grow and spread through the
conditioned zone. High pressure water (700 Psi or less) may be used to clean coils with fin thickness over
0.0095 inches thick. TEST THE SPRAY PRESSURE over a small corner of the coil to determine if the fins
will withstand the spray pressure.
For coils with fragile fins or high fin density, foaming chemical sprays and washes are available. Many coil
cleaners contain harsh chemicals, so they must be used with caution by qualified personnel only. Care
must be taken not to damage the coils, including fins, while cleaning.
CAUTION: Fin edges are sharp.
**WARNING**
BIOLOGICAL HAZARD. MAY CAUSE DISEASE. CLEANING SHOULD BE PERFORMED BY QUALIFIED PERSONNEL.
15
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ROUTINE ENERGY RECOVERY WHEEL MAINTENANCE
CAUTION: See **WARNING** on Page 1 and 11
MAINTENANCE OF THE ENERGY RECOVERY WHEEL
Annual inspection of the energy recovery wheel is recommended. Units ventilating smoking lounges and other
non-clean air spaces should have energy recovery wheel inspections more often based upon need. Inspections
for smoke ventilation applications are recommended bimonthly to quarterly until a regular schedule can be
established.
ACCESSING ENERGY RECOVERY WHEEL
For the ERH-20 and ERH-45, open the access door marked "Energy Wheel Cassette Access" (FIGURE 20).
UNPLUG the wheel drive motor and remove the metal spacer. Then pull the cassette out halfway (FIGURE 21).
The energy recovery wheel cassettes for model ERH-55 and ERH-90 do not slide out due to their size and
weight. Service to these energy wheel cassettes can be done through the Filter and Electrical Control Box
access doors, or by entering the unit through the Exhaust Blower access door.
**WARNING: Disconnect power to the unit before performing any type of service.**
FIGURE 20
FIGURE 21
16
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REMOVING THE ENERGY RECOVERY WHEEL SEGMENTS
Model ERH-20, 45, 55, & 90
Bracket Segment Retainer
Steel retainers are located on the
inside of the wheel rim (FIGURE 22).
Push the retainer toward center of
wheel, then lift up and away to
Lift Away
From Segment
release segments (FIGURE 23).
Catch-
Segment Retainer
Inside of Wheel Rim
Spoke
Push Toward Center
FIGURE 22
IMPORTANT! PLACE RETAINERS BACK IN THE ORIGINAL
POSITION BEFORE ROTATING THE ENERGY
RECOVERY WHEEL. OTHERWISE DAMAGE TO
RETAINER WILL OCCUR.
FIGURE 23
CLEANING ENERGY RECOVERY WHEEL SEGMENTS
If the wheel appears excessively dirty, it should be cleaned to ensure maximum operating efficiency. Only
excessive buildup of foreign material needs to be removed. DISCOLORATION AND STAINING OF ENERGY
RECOVERY WHEEL DOES NOT AFFECT ITS PERFORMANCE.
™
Thoroughly spray wheel matrix with household cleaner such as Fantastic or equivalent. Gently rinse with warm
water and using a soft brush remove any heavier accumulation. A detergent/water solution can also be used.
Avoid aggressive organic solvents, such as acetone. The energy recovery wheel segments can be soaked in the
above solution overnight for stubborn dirt or accumulation.
After cleaning is complete, shake the excess water from the wheel or segments. Dry wheel or segments before
placing them back into the cassette. Place wheel or segments back into cassette by reversing removal
procedures.
** DO NOT CLEAN ENERGY RECOVERY WHEEL SEGMENTS WITH WATER IN EXCESS OF 140°F
** DO NOT DRY ENERGY RECOVERY WHEEL SEGMENTS IN AIR IN EXCESS OF 140°F.
17
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PARTS LIST
7
3
8
6
1
5
2
9
7
4
10
Model ERH
(shown with indirect gas heater)
1. Supply blower
8. Electrical control box (standard features)
- Single point power
- Forward curved fan
- Adjustable motor mount for belt tensioning
- Adjustable sheaves for speed control
- Disconnect interlocked with access door
- Motor starters for the supply blower, exhaust
blower and energy wheel motors.
2. Vibrations isolators (quantity 4 per blower)
- Neoprene
- 24 Vac, control circuit with terminal strip
9. Supply air tempering options
- Electric heat
3. Energy recovery wheel cassette
- Hot water heat
4. Removable energy recovery wheel segments
- Indirect gas heat
5. Optional supply weatherhood with 2 in. aluminum
mesh filter
10. Exhaust blower
- Forward curved fan
- Adjustable motor mount for belt tensioning
- Adjustable sheaves for speed control
6. Optional exhaust weatherhood with birdscreen
7. Optional supply and exhaust air filter racks with 2
in. pleated, 30% efficient filters
18
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Trouble Shooting
Symptom
Possible Cause
Corrective Action
Blown fuse or open circuit
breaker.
Replace fuse or reset circuit breaker and check amps.
Defective motor or capacitor.
Motor starter overloaded.
Electrical.
Replace
Blower Fails to
Operate
Reset starter and check amps.
Check for On/Off switches. Check for correct supply voltage.
Check for broken or loose belts. Tighten loose pulleys.
Drive.
Control power (24 Vac) wiring
run is too long (resistance
Shorten wiring run to mechanical room or install a relay
which will turn unit on/off (C/F for relay information).
should not exceed 0.75 ohms).
Motor Starters
“Chatter” or Do
Not Pull In
Incoming supply power is
less than anticipated. Voltage
supplied to starter coil must
be within +10% / -15% of
nominal voltage stated on
the coil.
Need to increase supply power or use a special control
transformer which is sized for the actual supply power.
Cfm too high.
Check cfm and adjust drives if needed.
Static pressures are higher or
lower than design.
If higher, ductwork should be improved.
If lower, fan rpm should be lower.
Blower rotation is incorrect.
Motor voltage incorrect.
Motor horsepower too low.
Check rotation and reverse if necessary.
Motor Over Amps
Check motor nameplate versus supplied voltage.
See specifications and catalog for fan curves to determine if
horsepower is sufficient.
Shorted windings in motor.
Unit damper not fully open.
Replace motor.
Adjust damper linkage or replace damper motor.
System static pressure too high Improve ductwork to eliminate losses using good duct
practices.
Blower speed too low.
Check for correct drives and rpm with catalog data.
For 3-phase see Fan Wheel Rotation on page 11.
Fan wheels are operating
backwards.
Low Airflow (cfm)
Dirty filter or energy wheel.
Leaks in ductwork.
Follow cleaning procedures on pages 14 and 17.
Repair.
Elbows or other obstructions
may be obstructing fan outlet.
Correct or improve ductwork.
Belt slippage.
Adjust belt tension.
Blower fan speed too high.
Filter(s) not in place.
Check for correct fan rpm. Decrease fan speed if necessary.
Install filters.
High Airflow (cfm)
Insufficient static pressure (Ps)
(airflow resistance).
Induce Ps into system ductwork. Make sure grilles and
access doors are installed. Decrease fan speed if necessary.
* Always provide the unit model and serial number when requesting parts or service information. * Always check motor amps and compare to nameplate rating.
19
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Trouble Shooting
Symptom
Possible Cause
Corrective Action
One or Both
Blowers Turn Off
Intermittently and
Back on After
Blower fan motor overloads are Decrease fan speed.
tripping and auto-resetting.
Exhaust Only frost control
sensors are tripping.
Adjust frost temperature sensor set point as needed.
About 2 Minutes
Air seals are too tight.
See Energy Recovery Wheel on page 12
“Economizer” sensors are
operating.
Adjust temperature or enthalpy set points as needed.
Energy Wheel
Does NOT Turn
No power to wheel motor.
Make sure wheel drive is plugged in. Verify power is
available.
Wheel drive belt
Check for loose or broken belts. Replace belts (consult
factory).
Wheel motor overloads are
tripping, due to rubbing
between wheel and air seals.
Recheck air seals, make sure they are not too tight. See
Energy Recovery Wheel on page 12.
Energy Wheel
Runs Intermittently
Fan wheel rubbing on inlet
Adjust wheel and/or inlet cone. Tighten wheel hub or bearing
collars on shaft.
Bearings.
Replace defective bearings (s). Lubricate bearings. Tighten
collars and fasteners.
Wheel out of balance.
Replace or rebalance.
Loose wheel on shaft.
Tighten wheel setscrew.
Tighten sheave setscrew.
Loose motor or blower sheave.
Belts too loose.
Belts too tight.
Adjust belt tension after 24 hours of operation.
Excessive Noise or
Vibration
Loosen to maintain a 3/8 inch deflection per foot of span
between sheaves.
Worn belt.
Replace.
Motor base or blower loose.
Build up of material on wheel.
Bearing and drive misaligned.
Tighten mounting bolts.
Clean wheel and housing.
Realign.
Noise being transmitted by
duct.
Make sure duct work is supported properly. Make sure duct
work metal thickness is sized for proper stiffness. Check duct
size at discharge to ensure that air velocities are not too high.
* Always provide the unit model and serial number when requesting parts or service information. * Always check motor amps and compare to nameplate rating.
Warranty
Greenheck warrants this equipment to be free from defects in material and workmanship for a period of one year from
the purchase date. The energy recovery wheel is warranted to be free from defects in material and workmanship for a
period of five years from the purchase date. Any units or parts which prove defective during the warranty period will be
replaced at our option when returned to our factory, transportation prepaid.
Motors are warranted by the motor manufacturer for a period of one year. Should motors furnished by Greenheck prove
defective during this period, they should be returned to the nearest authorized motor service station. Greenheck will not
be responsible for any removal or installation costs.
Due to continuing product development Greenheck has the right to change specifications without notice
GREENHECK
Copyright © 2002 Greenheck Fan Corp.
IOM ERH FS
Rev. 1 January 2002
P.O. BOX 410 SCHOFIELD, WISCONSIN 54476-0410
PH. 715-359-6171
®
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