56
LEGEND FOR FIG.
THERMOSTAT/IGC 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 W — Thermostat Heat W1 — 1st Stage of Heating W2 — 2nd Stage of Heating X — Alarm Output
Y1 — 1st Stage of Cooling
Y2 — 2nd Stage of Cooling
| — | Circuit A | |
| AUX | — | Auxiliary Contact |
| AL | — | Ambient Limit |
| — | Circuit B | |
| C | — | Compressor Contactor |
| CAP | — | Capacitor |
| CB | — | Compressor Circuit Breaker |
| CCH | — | Crankcase Heater |
| CLO | — | Compressor Lockout |
| COMP | — | Compressor |
| CT BRK — | Circuit Breaker | |
| CR | — | Control Relay |
| DU | — | Dummy Terminal |
| ECB | — | Economizer Control Board |
| FCS | — | Fan Cycling Switch |
| FIOP | — | |
| FPT | — | Freeze Protection Thermostat |
| FS | — | Flame Sensor |
| FU | — | Fuse |
| GND | — | Ground |
| GV | — | Gas Valve |
| HACR — Heating, Air Conditioning, | ||
|
|
| and Refrigeration |
| HERM | — Hermetic | |
NOTES: | HPS | — | |
1. Factory wiring is in accordance with the National Electrical Codes. Any | I | — | Ignitor |
field modifications or additions must be in compliance with all applicable | IAQ | — | Indoor Air Quality |
codes. | IDM | — | |
2. Use 75° C min wire for field power supply. Use copper wires for all units. | IDR | — | Induced Draft Relay |
3. All circuit breakers “Must Trip Amps” are equal to or less than 156% RLA. | IFC | — | |
4. Compressor and fan motors are thermally protected. | IFCB | — | Indoor Fan Circuit Breaker |
protected against primary | IFM | — | |
5. The CLO locks out the compressor to prevent short cycling on compressor | IGC | — | Integrated Gas Controller |
overload and safety devices. Before replacing CLO, check these devices. | LOR | — | Lockout Relay |
LPS | — |
LS | — Limit Switch |
OAS | — |
OFC | — |
OFM | — |
PEC | — Power Exhaust Contactor |
PEM | — Power Exhaust Motor |
PL | — Plug |
PLP | — Phase Loss Protection |
QC | — Quick Connect |
QT | — Quadruple Terminal |
RAS | — Return Air Sensor |
RS | — Rollout Switch |
SAT | — |
TB | — Terminal Block |
TRAN | — Transformer |
TXV | — Thermostatic Expansion Valve |
W/AT | — With Auxiliary Trip |
| Terminal Block |
| Terminal (Unmarked) |
| Terminal (Marked) |
| Factory Wiring |
| Field Wiring |
| To Indicate Common Potential |
| Only. Not to Represent Wiring. |
| To Indicate FIOP or Accessory |
