Caution, Warning – Carrier 50PG03-07 User Manual

Page 9

UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment

damage.
The correct power phasing is critical to the operation of the

scroll compressors. An incorrect phasing will result in an

alarm being generated and compressor operation lockout.

Should this occur, power phase correction must be made to

the incoming power. Damage to compressor could result.

CAUTION

ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal

injury or death.
Unit cabinet must have an uninterrupted, unbroken

electrical ground to minimize the possibility of personal

injury if an electrical fault should occur. This ground may

consist of electrical wire connected to unit ground lug in

control compartment, or conduit approved for electrical

ground when installed in accordance with NEC; ANSI

(American National Standards Institute)/NFPA (National

Fire Protection Association), latest edition, and local

electrical codes.

WARNING

Field wiring must conform to temperature limitations for type “T”
wire. All field wiring must comply with NEC and local

requirements.
Operating voltage to compressor must be within voltage range

indicated on unit nameplate. On 3--phase units, voltages between

phases must be balanced within 2%.
Unit failure as a result of operation on improper line voltage or

excessive phase imbalance constitutes abuse and may cause
damage to electrical components.

Field Control Wiring (Units Without Optional

Humidi--MiZert Adaptive Dehumidification System)

Unit can be controlled with either a Carrier--approved accessory

thermostat or a Carrier--approved space temperature sensor. Install
thermostat according to the installation instructions included with

accessory. Locate thermostat assembly or space temperature sensor

on a solid interior wall in the conditioned space to sense average
temperature.
Route thermostat or space temperature sensor cable or equivalent
single leads of colored wire from subbase terminals through

conduit into unit to low--voltage connections as shown on unit

label wiring diagram and in Fig. 9 or 10.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (American
Wire Gauge) 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 connected at the thermostat and
will require a junction box and splice at the thermostat.

Set heat anticipator settings as follows:

VOLTAGE

Stage 1

(W1) ON

STAGE 1 AND 2

(W1 AND W2) ON

All

0.2

0.4

Settings may be changed slightly to provide a greater degree of

comfort for a particular installation.

DISCONNECT

PER NEC

FACTOR

POWER

WIRING

FIELD

POWER

WIRING

EQUIP GND

C.A1

LEGEND

C.A1 -- Compressor Contactor (A1)
EQUIP -- Equipment
GND -- Ground
NEC -- National Electrical Code

NOTE: The maximum wire size for C.A1 is 2/0.

C06237

Fig. 8 -- Field Power Wiring Connections

TB1

REMOVABLE JUMPER

THERMOSTAT ASSEMB Y

ROOFTOP UNIT

C06292

Fig. 9 -- Field Control Thermostat Wiring

T-55 SPT

T-56 SPT

T55
TB1

RED

ACK

RED

BLACK

WHITE

JUMPER

SEN

SET

SEN

ROOFTOP UNIT

C06239

Fig. 10 -- Field Control Space Temperature Sensor Wiring

Field Control Wiring (Units With Optional Humidi--

MiZert Adaptive Dehumidification System)

Units require temperature control inputs for cooling and heating
operation and humidity control inputs for Humidi--MiZer

operation.

50PG03