Chromalox NWH-185015 - Manual (Page 2)

Heater Model 240V 3 Phase Fig. 480V 3 Phase Fig.
NWH-185015 1 2
NWH-187515 1 2
NWH-1810015 1 2
NWH-1812515 1 2
NWH-1815015 1 2
NWH-1817515 1 2
NWH-1820015 1 2
OPERATION
1. Do not heat solutions that are corrosive to the heating element
sheath or the heating chamber.
WARNING: Type NWH Circulation Heaters are
equipped with copper heating elements and
galvanized-steel heating chambers. It is the
responsibility of the user 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
u p o n t h e h e a t i n g e l e m e n t s a n d c h a m b e r .
Chromalox cannot warrant any electric circula-
tion heater against failure by sheath corrosion
if such failure is the result of operating condi-
tions beyond our control.
2. Terminal ends of heater must be protected from drippings,
condensation, spray or direct spill-over of material. Their
presence at the terminals may damage heater electrical insula-
tion. Liquid-tight terminal enclosures are available to protect
heater. Check Factory.
3. If foreign material is carried by the liquid flow, install suitable
filters in the inlet pipe line to the heater.
4. Do not allow heater to operate when liquid flow is interrupted.
WARNING: Hazard of Shock. Any installation
involving electric heaters must be effectively
g r o u n d e d i n a c c o r d a n c e w i t h t h e N a t i o n a l
Electrical Code to eliminate shock hazard.
1. Be sure line voltage matches heater voltage (on nameplate).
2. Electric wiring to heater must be installed in accordance with
local and National Electrical Codesby a qualified person as
defined in the NEC.
3. Power controllers must be used when heaters are rated for 480
volt service or if the amperage rating of the heaters exceeds
the contact rating of the thermostat.
4. Refer to Wiring Diagram Table B for the proper wiring dia-
gram for connecting heater.
WIRING
Note: Dotted lines indicate “customer furnished.” However, Thermostat can be furnished by Chromalox if so specified on the order.
INSTALLATION
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 elements may be seriously damaged. (See Figure B)
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-18 is provided with mounting lugs to support the heat-
ing chamber. (See photo on previous page)
4. By using a slotted mounting assembly on either of the mount-
ing lugs, the heater chamber will be permitted to expand with
increasing temperature.
5. DANGER: Hazard of Fire. Provide minimum of 6” spac-
ing from chamber and related piping to nearest combustible
material. Avoid operation of heater near combustible fluids or
in combustible vapor or gas laden atmospheres.
6. Provide adequate space at terminal to end permit withdrawal
of the heater from chamber for servicing.
Table B — Wiring Diagrams
L1
L2
L3
Contactor
Contactor
Contactor
Thermostat
120V or
240V
120V or
240V
L1
L2
L3
Contactor
Contactor
Contactor
Thermostat
Figure B — Horizontal Mounting
Correct
Incorrect
Figure 1 – 240V 3-3 ø Figure 2 – 480V 3-3 ш