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Chromalox
®
DIVISION
4
SECTION
NWH
SALES
REFERENCE
DATE
SERVICE REFERENCE
Installation Instructions
and
RENEWAL PARTS IDENTIFICATION
PE407-10
161-048468-001
NOVEMBER, 2002
(Supersedes PE407-9)
GENERAL
INSTALLATION
© 2002 Chromalox, Inc.
Type NWH-6 Circulation Heater
(for Water Heating)
FIRE/EXPLOSION HAZARD. This heater is not
intended for use in hazardous atmospheres where
flammable vapors, gases, liquids or other com-
bustible atmospheres are present as defined in the
National Electrical Code. Failure to comply can
result in personal injury or property damage.
The NWH-6 series is a general-purpose water or water-based solution
circulation heater intended for use indoors. It is designed for 150 psig
at 350˚F per ANSI standards, -20˚F minimum.
The 6 copper-sheathed tubular elements are centered in a 5” diam-
eter galvanized steel heating chamber and sealed into a removable
steel flange. The assembly is surrounded by 1-1/2” insulation and
sheet metal jacket.
Depending upon the order specifications, the NWH-6 may or may
not be factory equipped with an AR-215A or other Chromalox ther-
mostat. Such thermostats function to control outlet temperatures and to
limit internal temperatures under abnormal flow conditions. These
controls do not fail safe.
The system designer is responsible for the safety
of this equipment and should install adequate
back-up controls and safety devices with their
electric heating equipment. Where the conse-
quences of failure could result in personal injury or
property damage, back-up controls are essential.
ELECTRIC SHOCK HAZARD. Disconnect all power
before installing or servicing heater. Failure to do so
could result in personal injury or property damage.
Heater must be installed by a qualified person in accor-
dance with the National Electrical Code, NFPA 70.
1. Vertical Mounting (Preferred) —
When the heater is vertically mounted, the terminal enclosure 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.
2. Horizontal Mounting (Optional) —
When mounting heater horizontally, inlet and outlet pipes must be
up. In any other position, heater cannot be purged of air, and ele-
ments may be seriously damaged. (See Figure B.)
Specifications — Table A
Incorrect
Correct
Figure A
Vertical Mounting
Correct
Incorrect
Dimensions (In.)
Watt
Model Volts Phase kW
Density
A B C
NWH-62415 1 or 3 24 45.8 41-3/4 30 11-3/8
NWH-63015 1 or 3 30 45.8 48-3/4 37 14-7/8
NWH-64015 3 40 45.8 60-1/4 48-1/2 20-5/8
NWH-65015 3 50 45.8 73-5/8 61-7/8 27-5/16
NWH-66015 3 60 45.8 86-5/8 74-7/8 33-7/8
240
or
480
A
C
25”
B
8-5/8”
16-1/16”
Thermostat
Type AR
Mounting Lugs
3/8” - 16
Threaded Holes -
1-1/2” Deep
1-1/4” Centers
2” Pipe Inlet
2” Pipe Outlet
1-3/8” Conduit
Openings
Figure B
Horizontal Mounting
WIRING
ELECTRIC SHOCK HAZARD. Any installation involv-
ing electric heaters must be performed by a quali-
fied person and must be effectively grounded in
accordance with the National Electrical Code to
eliminate shock hazard.
1. Be sure line voltage matches heater voltage (on nameplate).
2. All wiring should be done in accordance with local codes and the
National Electrical Code by a qualified person as defined in the
NEC.
3. Power controllers must be used when heaters are rated 3 phase and
when the heater amperage exceeds the rating of the thermostat.
4. Refer to Wiring Diagrams, Table B, to properly connect the
heater.
Wiring Diagrams - Table B
INSTALLATION
3. Whether vertically or horizontally, the heater should be rigidly
mounted so that vibration is at a minimum since excessive vibration
will result in erratic thermostat operation. The NWH-6 is provided
with mounting lugs to support the heating chamber. (See photo.)
4.
By using a slotted mounting assembly on either of the lugs, the heater
chamber will be permitted to expand with increasing temperature.
5. Provide adequate space at terminal end to permit withdrawal of the
heater from chamber should servicing be required.
FREEZE HAZARD. This unit is equipped with a ther-
mowell for process control or over-temperature con-
trol. Do not allow moisture to accumulate in ther-
mowell. Freezing temperatures can cause damage
that may result in the heated medium leaking into ter-
minal enclosure.
To prevent moisture accumulation in cryogenic applications or
when heater is exposed to freezing temperatures:
A. Slope conduit away from housing (drip loop).
B. Seal all conduit openings to moisture/explosion resistant ter-
minal enclosure.
C. Insulate terminal enclosure.
D. Fill thermowell(s) with silicone fluid when heater is mounted
with terminal enclosure up.
FIRE HAZARD. Since heaters are capable of develop-
ing high temperatures, extreme care should be taken
to:
A. Provide 6 inch minimum spacing from chamber and related
piping to combustible materials.
B. Do not operate heater in or near combustible fluids, vapors,
gases or dust-laden atmospheres as defined by the National
Electrical Code.
Model
240V, 480V, 480V, 480V,
2-3Ø Fig. 2-1Ø Fig. 3Ø Fig. 2-3Ø Fig.
NWH-62415 1 2 3 —
NWH-63015 1 2 3 —
NWH-64015 1 — — 4
NWH-65015 — — — 4
NWH-66015 — — — 4
Contactor
Contactor
Thermostat
1L1
1L2
1L3
2L1
2L2
2L3
120V
or
240V
NOTE: Dotted lines indicate “customer furnished.” However, Thermostat could have been furnished by Chromalox if so specified on the order.
Contactor
Contactor
Thermostat
120V
or
240V
Line
Figure 1 - NWH-6
240V, 2-3Ø ss
Figure 2 - NWH-6
480V, 2-1Ø
OPERATION
IMPORTANT: Type NWH Circulation Heaters are
equipped with copper heating elements and galva-
nized-steel heating chambers. It is the responsibil-
ity of the purchaser of the heater to know the
chemical composition of the corrosive solution and
the character of the materials entering the solution
as well as the corrosive effect of the solution upon
the heating elements and chamber.
Sheath corrosion can result in a ground fault
which, depending upon the solution being heated,
can cause an explosion or fire.
1. Do not heat solutions that are corrosive to the heating element
sheath or the heating chamber.
2. Terminal ends of heater must be protected from drippings, con-
densation, spray or direct spill-over of material. Their presence at
the terminals may damage heater electrical insulation. Liquid-tight
terminal enclosures are available to protect heater. Consult your
Local Chromalox Sales office.
3. If foreign material is carried by the liquid flow, install suitable fil-
ters in the inlet pipe line to the heater.
4. Do not allow heater to operate when liquid flow is interrupted.
FIRE/EXPLOSION HAZARD. Do not exceed the
Pressure-Temperature rating of the flange as listed in
ANSI B16.5.
MAINTENANCE
ELECTRIC SHOCK HAZARD. Disconnect all power
before installing or servicing heater. Failure to do
so could result in personal injury or property dam-
age. Heater must be installed by a qualified person
in accordance with the National Electrical Code,
NFPA 70.
1. Remove heating element assembly periodically to check heater
sheath for scaling, corrosion or excessive oxidation. Correct oper-
ating conditions to minimize sheath deterioration. Note:
Maintenance intervals to be determined by the user based on their
knowledge of the heated medium and operating conditions.
2. Periodically check temperature control and limit control operation
to insure accurate and safe process operation.
3. Check all electrical connections periodically and retighten connec-
tions which may have loosened in service. Replace wire and wire
terminals which show signs of oxidation which would interfere
with establishment of reliable electrical connections.
Figure 3 - NWH-6
480V, 3Ø ss
Figure 1 - NWH-6
480V, 2-3Ø ss
Contactor
Thermostat
120V, 240V
L1
L2
L3
Contactor
Contactor
Thermostat
1L1
1L2
1L3
2L1
2L2
2L3
120V
or
240V
WIRING (cont.d’)
NOTE: Dotted lines indicate “customer furnished.” However, Thermostat could have been furnished by Chromalox if so specified on the order.
2150 N. RULON WHITE BLVD., OGDEN, UT 84404
Phone: 1-800-368-2493 www.chromalox.com
TA - Y2 - EF
Litho in U.S.A.
RENEWAL PARTS IDENTIFICATION
Heating
Model VoltsPhase kW
Elements
NWH-62415 240 2-3Ø 24 155-115848-016
NWH-62415 480 2-1Ø 24 155-115848-017
NWH-62415 480 3Ø 24 155-115848-018
NWH-63015 240 2-3Ø 30 155-115848-020
NWH-63015 480 2-1Ø 30 155-115848-021
NWH-63015 480 3Ø 30 155-115848-022
NWH-64015 240 2-3Ø 40 155-115848-024
NWH-64015 480 2-3Ø 40 155-115848-025
NWH-65015 480 2-3Ø 50 155-115848-027
NWH-66015 480 2-3Ø 60 155-115848-029
PARTS COMMON TO ALL HEATERS
AR-215A Thermostat . . . . . . . . . . . . . . . . . . . . . . .300-057502-015
AR Mounting Bracket . . . . . . . . . . . . . . . . . . . .027-011378-001 (2)
Flexitallic Gasket . . . . . . . . . . . . . . . . . . . . . . . . .132-073008-013
Standard Gasket . . . . . . . . . . . . . . . . . . . . . . . . . .132-017222-003
Note: When ordering parts for Model Numbers suffixed by “XX” or any other letter
or letters, order Renewal Parts on special order basis. Give the name of the part, volt-
age, wattage and any other special features to your Chromalox Representative or the
factory.
Note: Number in ( ) indicates quantity of same part number used.
Limited Warranty:
Please refer to the Chromalox limited warranty applicable to this product at
http://www.chromalox.com/customer-service/policies/termsofsale.aspx.
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