Sterling TD - Manual (Page 12)

12
ELECTRICAL CONNECTIONS
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 duct furnace data plate
and electrical rating of the transformer should be checked
before energizing the duct furnace 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. Failure to do so may result in personal
injury or property damage.
USE COPPER CONDUCTORS ONLY!
UNIT TERMINALS ARE NOT DESIGNED TO ACCEPT
OTHER TYPES OF CONDUCTORS. Failure to do so
may cause damage to the equipment.
It is recommended that the electrical power supply to each
duct furnace 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 duct furnace
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 7a, 7b, 7c, 7d, 7e, 7f, and 7g.
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 feet (1.5m) above
the fl oor, 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 the duct furnace 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.
Figure 7a -
Low-voltage
Thermostat Wiring
Single Stage
Figure 7b -
Low-voltage
Thermostat Wiring
Two Stage
Figure 7c -
Low-voltage
T834H, 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 inside of the control access panel or enclosed
in the installation instructions envelope). Should any
original wire supplied with the unit have to be
replaced including high limit wires, it must be
replaced with wiring material having a temperature
rating of at least 105°C.
Standard single stage and optional two stage wiring
diagrams are included in this manual. Duct furnaces
equipped with modulating gas controls and other optional
equipment will be shipped with a unit-specifi c wiring
diagram.
D6922C
D8541
D4788