THERMOSTAT
The room thermostat should be located on an inside wall
approximately 56 inches above the floor where it will not be
subject to drafts, sun exposure or heat from electrical fixtures
or appliances. Follow manufacturer’s instructions enclosed with
thermostat for general installation procedure. Seven color
coded insulated wires (#18 AWG) should be used to connect
thermostat to unit.
POWER AND CONTROL WIRING
Field wiring to the unit must conform to provisions of the National
Electrical Code, ANSI / NFPA No. 70 (in U.S.A.), current Canadian
Electrical Code C22.1 (in Canada) and/or local ordinances. The
unit must be electrically grounded in accordance with NEC and
CEC (as specified above) and/or local codes. Voltage tolerances
which must be maintained at the compressor terminals during
starting and running conditions are indicated on the unit Rating
Plate and the Unit Application Data table.
The internal wiring harness furnished with this unit is an integral
part of a ETL and CGA design certified 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. Wire entry
at knockout openings require conduit fittings to comply with
NEC (in U.S.A.), CEC (in Canada) and/or local codes. Refer to
the Dimensions and Clearnaces Figure 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 and the same minimum gauge as the replaced wire.
Electrical line must be sized properly to carry the load. Use
copperconductors 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
wiring 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 the Typical Field Wiring figure and to the appropriate
unit wiring diagram for control circuit and power wiring
information.
RH
RC
Y1
Y2
W1
W2
G
R
RH
Y1
Y2
W1
W2
G
B
LED1
LED2
COM
A1
A2
T
T
4
4
3
3
Y1
Y2
W1
W2
G
B
X
A1
A2
L1
L3
L2
RC
R
Y1
Y2
W1
W2
G
B
X
A1
A2
Y3
NOT USED
TO REMOTE SENSOR
2THO4702224 IF USED
1
Electronic programmable thermostat 2ET04700224 (includes subbase).
2
Terminal block 1TB- located on relay board in 24-volt section of the unit control box.
3
Second stage heating is not required on units with a single stage electric heater.
4
Terminals A1 and A2 provide a relay output to close the outdoor economizer dampers
when the thermostat switches to the set-back position.
NOTE: Fans switch must be in "ON" position for minimum ventilation during heater operation.
LINE VOLTAGE
TERMINAL
BLOCK 2TB
IN CONTROL BOX
GROUND LUG
Refer to the
ELECTRICAL DATA
tables to size the
power wiring, the
fuses and the
disconnect switch.
24 VOLT
TRANSFORMER
COOLING / HEATING (24 VOLT THERMOSTAT)
THERMOSTAT
1
TERMINALS
CONTROL WIRING
UNIT TERMINAL
BLOCK 1TB
2
1
24 Volt Thermostat 2TH04701024 or 2TH04701524
(with Subbase 2TB04700324).
2
Terminal strip 1TB - located on relay board in 24-volt section
of the unit control box.
3
Second stage heating is not required on units with a single stage
electric heater.
THERMOSTAT
1
TERMINALS
UNIT TERMINAL
BLOCK 1 TB
2
COOLING ONLY (24 VOLT THERMOSTAT)
24 VOLT
TRANSFORMER
POWER WIRING
ADD
JUMPER
ADD
JUMPER
ADD
JUMPER
FIG. 5 - TYPICAL FIELD WIRING
Wire Size
1
AWG. Gauge
22
20
19
18
16
40
120
150
190
305
Maximum Wire Length
2
Feet
Notes:
1. Solid, Class II copper wire
2. Based on a voltage drop of 1.2 volts per wire.
3. Total wire length is from unit to room thermostat, and back to unit
TABLE 2 - CONTROL WIRE SIZES
530.18-N6Y
Unitary Products Group
5
