insulated wires 1.0mm
2
(#18 AWG) should be used to connect
thermostat to unit. Eight conductors are required.
The subbase on the low voltage thermostat includes an
“Emergency Heat ” position on the system switch and a pilot
light. In the “Emergency Heat” position, the thermostat
provides electric resistance heat only. The compressors will not
run. The pilot light indicates that the switch is on “EM HT”. Nine
conductors are required for this application.
POWER AND CONTROL WIRING
Field wiring to the unit and electrical grounding of the unit must
conform to the applicable national, and local or municipal
codes. Voltage tolerances which must be maintained at the
compressor terminals during starting and running conditions
are indicated on the unit Rating Plate and Table 1.
The internal wiring harness furnished in this unit is an integral
part of the unit. Field alteration to comply with electrical codes
should not be required.
A fused disconnect switch should be field provided for the unit.
The switch must be separate from all other circuits. Refer to
Figure 7 for installation location. If any of the wire supplied with
the unit must be replaced, replacement wire must be of the type
shown on the wiring diagram. Refer to Table 7 for electrical
data.
Electrical line must be sized correctly to carry the load. USE
COPPER CONDUCTORS ONLY. Each unit must be wired
with a separate branch circuit fed directly from the meter panel
and properly fused.
CAUTION: When connecting electrical power and control wir-
ing to the unit, waterproof type connectors MUST
BE USED so that water or moisture cannot be
drawn into the unit during normal operation. The
above waterproofing conditions will also apply
when installing a field-supplied disconnect switch.
Refer to Figure 5 for typical field wiring and to the appropriate
unit wiring diagram for control circuit and power wiring
information.
OPTIONAL ELECTRIC HEATERS
The factory installed heaters are wired for single point power
supply. Power supply need only be brought into the single point
terminal block and thermostat wiring to the low voltage terminal
strip located in the upper portion of the unit control box.
035-18895-000-A-0902
Unitary Products Group
5
FIG. 5 - TYPICAL FIELD WIRING
Heater
Model
Minimum
Airflow
m
3
/s (CFM)
Output by Operation Mode and
Heat Stage
kW @ 400/415V*
Normal Operation
Emergency Heat
180
W1
W2
W1
W2
E018
2.12
(4500)
Mechanical 11.3/13.5 11.3/13.5
None
E036
2.12
(4500)
Mechanical 11.3/13.5 11.3/13.5 11.3/13.5
E054
2.36
(5000)
Mechanical 11.3/13.5 11.3/13.5 22.6/26.9
E072
2.36
(5000)
Mechanical 22.6/26.9 22.6/26.9 22.6/26.9
*Refer to Table 8 for total heater output kW for the respective heater.
TABLE 2 - ELECTRIC HEAT APPLICATION DATA
CONTACTOR
NEUTRAL
TERMINAL
BLOCK
GRD.
LUG
NOTE: REFER TO ELECTRICAL DATA TABLES
TO SIZE THE WIRE, DISCONNECT SWITCH AND
OVERCURRENT PROTECTION.
FIELD-SUPPLIED
DISCONNECT
THREE
PHASE
POWER
SUPPLY
POWER WIRING
