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(Supersedes PE424)
PE424-1
NWH
161-058005-001
APRIL, 1999
4
and
Installation, Operation
RENEWAL PARTS IDENTIFICATION
INSTALLATION
GENERAL
© 2010 Chromalox, Inc.
Type NWH-18 Circulation
Heater for Water Heating
(150 Pound Construction)
WARNING: Hazard of Shock. Disconnect all power
before installing heater.
1. Vertical Mounting (Preferred) —
When the heater is vertically mounted, the terminal housing
will be at the top of the heater. The water inlet pipe will be
located on the side near the bottom of the heater and the outlet
pipe at the top.
The axis of the chamber will be in a vertical position as in the
photo above and as in Figure A.
Note: A drain pipe located at the bottom of the heater should
be provided and enough room left, when mounting heater, to
allow draining the heater.
WARNING: This heater is not intended for use in
hazardous 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.
The NWH-18 series is a general-purpose water or water-based
solution circulation heater intended for use indoors. It is designed
for 150 psig at 550°F per ANSI standards.
The 18 copper-sheathed tubular elements are centered in a 8”
diameter galvanized steel heating chamber and welded to a
removable galvanized steel flange. The assembly is surrounded
by 3” insulation and sheet metal jacket.
Depending upon the order specifications, the NWH-18 may or
may not be factory equipped with an AR or other Chromalox
thermostat. Such thermostats function to control outlet tempera-
tures and to limit internal temperatures under abnormal flow con-
ditions. These controls do not fail-safe.
WARNING: Users should install adequate back-up
controls and safety devices with their electric
heating equipment. Where the consequences of
failure may be severe, back-up controls are essen-
tial. Although the safety of the installation is the
responsibility of the user, Chromalox will be glad
to make equipment recommendations.
Specifications — Table A
Dimensions (In.)
Model
Volts Phase kW W/In
2
ABC
NWH-185015 240 or 480 3 50 42 45
7
/8 24
11
/16 21
3
/16
NWH-187515 240 or 480 3 75 45 53
7
/8 32
11
/16 29
3
/16
NWH-1810015 240 or 480 3 100 49 60
7
/8 39
11
/16 36
3
/16
NWH-1812515 240 or 480 3 125 50 68
1
/2 47
5
/16 43
13
/16
NWH-1815015 240 or 480 3 150 50 78 56
13
/16 53
5
/16
NWH-1817515 240 or 480 3 175 50 87 65
13
/16 62
5
/16
NWH-1820015 240 or 480 3 200 50 97 75
13
/16 72
5
/16
3/4-10 Tap
Mounting
Lugs
2 1/2” Pipe
Outlet
2 1/2” Pipe
Inlet
B
C
A
151/8”
Incorrect
Correct
Figure A — Vertical Mounting