Sterling SC - Manual (Page 12)

12
HAZARDOUS VOLTAGE!
DISCONNECT ALL ELECTRIC
POWER INCLUDING REMOTE
DISCONNECTS BEFORE
SERVICING. Failure to
disconnect power before
servicing can cause severe
personal injury or death.
Standard units are shipped for use on 115 volt, 60 hertz,
single phase electric power. The motor name-plate and
electrical rating of the transformer should be checked
before energizing the unit heater electrical system. All
external wiring must conform to the latest edition of
ANSI/NFPA No. 70, United States National Electrical
Code, and applicable local codes; in Canada, to the
Canadian Electrical Code, Part 1, CSA Standard C22.1.
Do not use any tools (i.e. screwdriver,
pliers, etc.) across terminals to check for power. Use
a voltmeter.
It is recommended that the electrical power supply to
each unit heater be provided by a separate, fused, and
permanently live electrical circuit. A disconnect switch of
suitable electrical rating should be located as close to
the gas valve and controls as possible. Each unit heater
must be electrically grounded in accordance with the
latest edition of the United States National Electrical
Code, ANSI/NFPA No. 70, or CSA Standard C22.1. Refer
to Figures 6a, 6b, 6c, 6d, 6e, 6f and 6g.
THERMOSTAT WIRING AND LOCATION:
NOTICE: The thermostat must be mounted on a
vertical, vibration-free surface, free from air currents,
and in accordance with the furnished instructions.
Mount the thermostat approximately 5' (1.5m) above
the floor, in an area where it will be exposed to a free
circulation of average temperature air. Always refer to
the thermostat instructions, as well as our unit wiring
diagram, and wire accordingly. Avoid mounting the
thermostat in the following locations:
1. Cold Areas - Outside walls or areas where drafts
may affect the operation of the control.
2. Hot Areas - Areas where the sun's rays, radiation,
or warm air currents may affect the operation of
the control.
3. Dead Areas - Areas where the air cannot circulate
freely, such as behind doors or in corners.
ELECTRICAL CONNECTIONS
Figure 6a -
Low-voltage
Thermostat Wiring
Single Stage
Figure 6b -
Low-voltage
Thermostat Wiring
Two Stage
Figure 6c -
Low-voltage
T834H or T834N
(or equivalent)
Thermostat Wiring
Single Stage
NOTICE: The start-up fan delay should not exceed
30 seconds from a cold start.
IMPORTANT: For all wiring connections, refer to the
wiring diagram shipped with your unit (either affi xed
to the side jacket or enclosed in the installation
instructions envelope). Should any original wire
supplied with the heater have to be replaced, it
must be replaced with wiring material having a
temperature rating of at least 105°C.
Should any high limit wires have to be replaced,
they must be replaced with wiring material having a
temperature rating of 200°C minimum.