®
Chromalox
SERVICE REFERENCE
Installation, Operation
and
MAINTENANCE INSTRUCTIONS
DIVISION
SALES
4
SECTION NWHMT
(Supersedes PE439-1)
REFERENCE
PE439-2
161-303186-001
DATE
APRIL, 1999
Type NWHMT Circulation Heater
(for Water Heating)
1-1/16” Dia. K.O.
for 3/4” Conduit
Internal
Thermostat
9-1/4”
Specifications — Table A
1” Pipe
Outlet (Std.)
Dimensions (In.)
3”
C
Model
Volts
Phase
kW
W/In2
A
B
C
NWHMT-3305
NWHMT-3455
NWHMT-3605
NWHMT-3905
NWHMT-31205
NWHMT-31505
NWHMT-31805
1
20, 240 or 480
240 or 480
240 or 480
240 or 480
240 or 480
240 or 480
240 or 480
1 or 3
1 or 3
1 or 3
1 or 3
1 or 3
1 or 3
1 or 3
3
4.5
6
50
50
50
50
50
50
50
21-5/8
21-5/8
34-3/4
34-3/4
57-1/2
57-1/2
57-1/2
9-3/8
—
2 Mtg. Lugs ea. with
two 3/8” - 16 x 1-1/2”
deep holes on 1-1/4”
centers
9-3/8
—
B
A
22-1/2
22-1/2
45-1/4
45-1/4
45-1/4
16-1/2
16-1/2
39-1/4
39-1/4
39-1/4
9
12
15
18
1” Pipe
Inlet (Std.)
3”
3/8” NPT
Pipe Plug
7”
GENERAL
metal jacket.
WARNING: This heater is not intended for use in haz-
ardous atmospheres where flammable vapors, gases,
liquids or other combustible atmospheres are present
as defined in the National Electrical Code. Failure to
comply can result in explosion or fire.
Depending upon the specifications, the NWHMT may or may not
be factory equipped with AR or other Chromalox thermostats. Such
thermostats function to control outlet temperatures and limits internal
temperatures under abnormal flow conditions. These controls do not
fail-safe.
Hazardous area terminal housings are available, consult your
Local Chromalox representative for details.
The NWHMT series is a general-purpose water circulation heater
intended for use indoors.
The three Copper sheathed tubular elements are centered in a 2-
1/2” diameter galvanized heating chamber and sealed in a removable
screwplug. The assembly is surrounded by 1-1/2” insulation and sheet
CAUTION: Users should install adequate back-up con-
trols and safety devices with their electric heating
equipment. Where the consequences of failure may
be severe, back-up controls are essential. Although
the safety of the installation is the responsibility of the
user, Chromalox will be glad to make equipment rec-
ommendations.
INSTALLATION
ments may be seriously damaged (Figure 2).
WARNING: Hazard of Shock. Disconnect all power
3. The NWHMT series of circulation heaters are provided with
mounting lugs to support the heater chamber. Refer to drawing
above for location of these mounting lugs.
before installing heater.
1. Vertical mounting (axis of chamber vertical, see above drawing.)
is preferred with terminal housing at top of heater (Figure 1).
2. When mounting heater horizontally, inlet and outlet pipes must be
up. In any other position, heater cannot be purged of air and ele-
4. Mount heaters to permit unrestrained expansion of chamber due to
temperature. This can be accomplished by using a slotted mount-
ing assembly on either of the lugs.
Correct
Incorrect
Correct
Incorrect
Figure 2 — Horizontal Mounting
Figure 1 — Vertical Mounting
© 2010 Chromalox, Inc.
Download from Www.Somanuals.com. All Manuals Search And Download.
|