On 208/230-v units, transformer no. 1 is wired for 230-v.
If 208/230-v unit is to be run with 208-v power supply, the
transformer must be rewired as follows:
1. Remove cap from red (208-v) wire.
2. Remove cap from spliced orange (230-v) wire. Discon-
nect orange wire from black unit power wire.
3. Cap orange wire.
4. Splice red wire and black unit power wire. Cap wires.
IMPORTANT: Be certain unused wires are capped.
Failure to do so may damage the transformers.
FIELD CONTROL WIRING — Install either a Carrier-
approved accessory thermostat or a CCN (Carrier Comfort
Network) compatible temperature sensor. A control box dia-
gram is shown in Fig. 12.
Thermostat Wiring — Install a Carrier-approved accessory
thermostat assembly (per current price pages) according to
the installation instructions included with the accessory or
these instructions. Locate thermostat assembly on a solid wall
in the conditioned space to sense average temperature.
Route thermostat cable or equivalent single leads of
colored wire from subbase terminals to low-voltage connec-
tions as shown on unit label wiring diagram and in Fig. 13.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (Amer-
ican Wire Gage) insulated wire (35 C minimum). For 50 to
75 ft, use no. 16 AWG insulated wire (35 C minimum). For
over 75 ft, use no. 14 AWG insulated wire (35 C minimum).
All wire larger than no. 18 AWG cannot be directly con-
nected to the thermostat and will require a junction box and
splice at the thermostat.
Set heat anticipators settings to 0.1 for all voltages. Set-
tings may be changed slightly to provide a greater degree of
comfort for a particular installation.
Sensor Wiring — The temperature sensor is wired into the
unit control board. See Fig. 14.
The unit is controlled with a T-55 or T-56 zone sensor.
Terminal T1 (T-55) or TH (T-56) on the sensor is connected
to T1 of the base module board. Terminal T2 (T-55) or COM
(T-56) on the sensor is connected to T2 on the base module
board. If a T-56 set point override sensor is used, the over-
ride connection SW on the sensor is connected to T3 on the
base module board.
If more than one sensor is being used and averaged, sen-
sors must be wired in multiples of 4 or 9. See Fig. 15.
Remote Field Control — A switch closure across terminals
R and W1 on TB-3 will initiate the Occupied mode. This
can be done manually as well as through a field-supplied
timeclock.
LEGEND
EQUIP — Equipment
GND — Ground
MCM — Thousand Circular Mils
NEC — National Electrical Code
TB — Terminal Block
NOTE: Maximum wire size for TB1 is 500 MCM.
Fig. 11 — Field Power Wiring Connections
LEGEND
CB — Circuit Breaker
DIP — Dual In-Line Package
FU — Fuse
GND — Ground
IFC — Indoor Fan Contactor
OFC — Outdoor Fan Contactor
PEC — Power Exhaust Controller
PES — Power Exhaust Sequencer
TB — Terminal Block
TRAN — Transformer
Fig. 12 — Control Box Diagram
Fig. 13 — Field Control Thermostat Wiring
11
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