Chromalox NWHMTO - Manual (Page 2)

WIRING
WARNING: Hazard of Shock. Any installation involving
electric heaters must be effectively grounded in
accordance with the National Electrical Code to elim-
inate shock hazard.
1. Electrical wiring to heater must be installed in accordance with the
National Electrical Code and local electrical codes by a qualified
person as defined in the NEC.
2. When element wattages are not equal, heaters must not be con-
nected in series.
3. Electrical wiring to heater should be connected in rigid conduit or
in flexible hose to keep corrosive vapors and liquids out of the ter-
minal housing. If high humidity is encountered, the conduit should
slope down away from the heater.
4. If flexible cord is employed, a watertight connector should be used
for entry of the cord into the terminal box. Outdoor applications
require liquid-tight conduit and connectors.
5. Bring the power line wires through the opening in the terminal
box. Connect line wire as shown in the diagram. (Figures 1 thru 3)
Note: Dotted lines indicate “customer furnished.”
OPERATION
1. Do not heat materials that are corrosive to the heating element
sheath or chamber. For oil heating service, drain may be provided
from bottom of chamber. Check factory.
2. Terminal ends of heater must be protected from drippings conden-
sation spray or direct spill-over of material whose presence at the
terminals may damage heater electrical insulation. Liquid-tight ter-
minal enclosures are available to protect heater. Check with local
sales representative.
3. If foreign material is carried by the oil flow, install suitable filters
in the inlet pipe line to the heater.
4. Do not allow heater to operate when fluid flow is interrupted.
MAINTENANCE
WARNING: Hazard of Shock. Disconnect all power
before servicing heater.
1. Remove heating element assembly periodically to check heater
sheath for corrosion or excessive oxidation. Correct operating con-
ditions to minimize sheath deterioration.
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 terminals
which show signs of oxidation which would interfere with estab-
lishment of reliable electrical connections.
RENEWAL PARTS IDENTIFICATION
Thermostat 60-250˚F ...................................................300-048518-013
2150 N. RULON WHITE BLVD., OGDEN, UT 84404
Phone: 1-800-368-2493 www.chromalox.com
TA - U0 - EF
Litho in U.S.A.
3 Pole Contactors 3 Heating Elements
Line
Control
Volts
Thermostat
2 Pole Contactors
1, 2, or 3 Heating Elements
in Series
Line
Control
Volts
Thermostat
or Parallel
3 Pole Contactors 3 Heating Elements
Line
Control
Volts
Thermostat
Figure 1 — For Three Phase WYE Heaters Figure 2 — For Single Phase Heaters Figure 3 — For Three Phase Delta Heaters
Limited Warranty:
Please refer to the Chromalox limited warranty applicable to this product at
http://www.chromalox.com/customer-service/policies/termsofsale.aspx.