Troubleshooting - Carrier COBRA 48/50HJ004-014 Installation And Service

NOTES:
1. If any of the original wire furnished must be replaced, it must be
replaced with Type 90° C wire or its equivalent.
2. Three phase motors are protected under primary single phasing
conditions.
3. Thermostat: HH07AT170, 172.
Subbase: HH93AZ176, 177, 178, and 179.
4. Set heat anticipator at .14 amp for 1st stage and .14 amp for 2nd
stage.
5. Use copper conductors only.
6. TRAN is wired for 230-v unit. If unit is to be run with 208-v power
supply, disconnect BLK wire from 230-v tap (ORN) and connect
to 208-v tap (RED). Insulate end of 230-v tap.
C — Contactor
CAP — Capacitor
CER — Compressor Energy Recovery section
CH — Crankcase Heater
CLO — Compressor Lockout
COC — Cool Changeover Relay
COH — Heat Changeover Relay
COMP — Compressor Motor
CR — Cooling Relay
CTD — Compressor Time Delay
DB — Defrost Board
DFT — Defrost Thermostat
DM — Damper Motor
DR — Defrost Relay
EQUIP — Equipment
FPT — Freeze-Up Protection Thermostat
FR — Fan Relay
FU — Fuse
GND — Ground
HM — Humidity Relay
HPS — High-Pressure Switch
HR — Heating Relay
HS — Hall Effect Sensor

TROUBLESHOOTING

Use Tables 3 and 4, and Fig. 19 and 20 when troubleshooting this unit.
I — Ignitor
IDM — Induced Draft Motor
IFC — Indoor Fan Contactor
IFM — Indoor Fan Motor
IGC — Integrated Gas Unit Control (48HJ only)
LTLO — Low Temp Cooling Lockout
LPS — Low-Pressure Switch
LS — Limit Switch
MGV — Main Gas Valve
OATC — Outdoor-Air Thermostat (Cool)
OATH — Outdoor-Air Thermostat (Heat)
OCR — Occupied Relay
OF — Outdoor Fan
OFM — Outdoor Fan Motor
OLR — Overload Relay
PL — Plug Assembly
QT — Quadruple Terminal
RS — Rollout Switch
RVS — Reversing Valve Solenoid
SEN — Sensor
TB — Terminal Block
TRAN — Transformer
Fig. 19 — Typical Wiring Schematic (Standard Controls)
LEGEND
38
Field Splice
Marked Wire
Terminal (Marked)
Terminal (Unmarked)
Terminal Block
Splice
Splice (Marked)
Factory Wiring
Field Control Wiring
Field Power Wiring
Accessory or Optional Wiring
To indicate common potential
only. Not to represent wiring.