Carrier 48/50AJ specifications 117

LEGEND AND NOTES FOR FIG. 15-25

LEGEND

A— Circuit A

AUX — Auxiliary Contact

B— Circuit B

BP — Building Pressure Transducer

C— Contactor, Compressor

CAP — Capacitor

CB	— Circuit Breaker
CCB	—	Control Circuit Breaker
CCH	—	Crankcase Heater
CCN	—	Carrier Comfort Network®
CEM	—	Controls Expansion Module
COMP	—	Compressor Motor
CR	— Control Relay
CS	—	Compressor Safety
CSB	— Compressor Current Sensing Board
DP	—	Duct Pressure Sensor
DPT	—	Discharge Pressure Transducer
DS	—	Disconnect Switch
ECB-1	—	Economizer Control Board
ECB-2	— Building and Supplier Air Control Board
EDT	— Evaporator Discharge Air Temperature
FIOP	—	Factory-Installed Option
FS	—	Flame Sensor
FU	—	Fuse
GND	—	Ground
HC	— Heat Contactor
HGBP	—	Hot Gas Bypass
HIR	—	Heat Interlock Relay
HPS	—	High Pressure Switch
HR	— Heat Relay
HS	— Hall Effect Induced Draft Motor Switch
IAQ	—	Indoor Air Quality
IDF	—	Induced Draft Fan
IDM	—	Induced Draft Motor
IFC	—	Indoor Fan Contactor
IFCB	— Indoor Fan Circuit Breaker
IFM	—	Indoor Fan Motor
IGC	— Integrated Gas Control Board
IP	—	Internal Compressor Protector
LAT	— Staged Gas Temperature Sensor
LEN	—	Local Equipment Network
LS	—	Limit Switch
MBB	— Main Base Board
MGV	— Main Gas Valve
NEC	—	National Electrical Code
OARH	— Outdoor Air Relative Humidity
OAT	— Outdoor Air Temperature Sensor
OFC	—	Outdoor Fan Contactor
OFM	—	Outdoor Fan Motor
PEC	—	Power Exhaust Contactor
PEM	—	Power Exhaust Motor

NOTES:

1.Factory wiring is in accordance with the National Electrical Codes. Any field modifications or additions must be in compli- ance with all applicable codes.

2.Use 75° C min wire for field power supply, use copper wires for all units.

3.All circuit breakers “Must Trip Amps” are equal to or less than 156% RLA.

PL	—	Plug
RARH —		Return Air Relative Humidity
RAT	—	Return Air Temperature Sensor
RLA	—	Rated Load Amps
RLY	—	Relay
RS	—	Rollout Switch
SCB	—	Staged Gas Heat Control Board
SCT	—	Saturated Condensing Temperature Sensor
SDU	—	Scrolling Marquee Display
SST	—	Saturated Suction Temperature Sensor
T-55	—	Room Temperature Sensor
T-56	—	Room Temperature Sensor with Setpoint
TB	—	Terminal Block
TRAN —		Transformer
VAV	—	Variable Air Volume
VFD	—	Variable Frequency Drive

Terminal Block

Terminal (Unmarked)

Terminal (Marked)

Splice

Factory Wiring

Field Wiring

To indicate common potential only.

Not to represent wiring.

To Indicate FIOP or Accessory

THERMOSTAT MARKINGS

BM — Blower Motor

C— Common CM — Inducer Motor

CS — Centrifugal Switch

G— Fan

IFO — Indoor Fan On

L1 — Line 1

R— Thermostat Power

RT — Power Supply

SS— Speed Sensor

W1 — Thermostat Heat Stage 1

W2 — Thermostat Heat Stage 2

X— Alarm Output

Y1 — Thermostat Cooling Stage 1

Y2 — Thermostat Cooling Stage 2

4.Compressor and fan motors are thermally protected — three phase motors protected against primary single phase conditions.

5.Red jumper wire must be added between R, W1, and W2 for space temperature sensor and all VAV units with heat and tem- porarily during Service Test mode when the heaters need to operate.

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