Page 4 of 13
507296-01
Issue 1650
Electrical Wiring
All field wiring must be done in accordance with National
Electrical Code recommendations, local codes, and
applicable requirements of UL Standards, or in accordance
with Canadian Electrical Code recommendations, local
codes, or CSA Standards. Power wiring, disconnect
means, and over-current protection are to be supplied by
the installer. Refer to the unit rating plate for maximum
over-current protection and minimum circuit ampacity, as
well as operating voltage. The power supply must be sized
and protected according to specifications supplied.
The unit must be grounded with a separate ground
conductor. See Figure 4 for typical field wiring connection.
The wiring diagram can be found on the unit inside the
access panel. Low voltage control wiring are terminal strip
or pigtail leads located on the main control box and are
color-coded to match the connection called out on the
wiring schematic.
When connecting electrical power and control wiring
to the unit, waterproof-type connectors must be used
so that water or moisture cannot be drawn into the unit
during normal operation.
CAUTION
Units are factory wired for a 230-volt power supply.
If power supply is 208 volts, it will be necessary to
change a wire connection on the unit transformer from
240V terminal to 208V terminal as shown on the wiring
diagram.
Use only copper conductors.
If any of the original unit wiring is replaced, the same size
and type wire must be used.
Thermostat
The room thermostat should be located on an inside
wall where it will not be subject to drafts, sun exposure,
or heat from electrical fixtures or appliances. Follow the
manufacturer’s instructions enclosed with the thermostat
for general installation procedure. Color-coded insulated
wires (#18 AWG) should be used to connect the thermostat
to the unit. A minimum of five wires are required for proper
installation.
If 208 Volt is supplied, transformer connection must be
changed
Single Phase
Power Supply
Ground
Lug
Contactor
Field-Supplied Fused
or Circuit Breaker
Disconnect
Figure 3. 208/230 Line Voltage Wiring
Figure 4. Typical Wiring Connections
*
“O” connection used only on heat pump models
*
W1, W2 can be used to stage electric heat accessory on 10,
15 & 20 kW models. 5 And 7 kW heater accessory function
off W1 only.
