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| Wall Wire | Thermostat Wire | Terminal | Usage |
|---|---|---|---|
| White | White | Common | |
| Black | Red | Power | |
| Red | Brown | Heat | |
| Orange | Yellow | Y | AC |
| Green | Green | G | Fan |
| Marking | Wire Color Code | Description |
|---|---|---|
| R | Red | Power, 24 Vac transformer |
| Rc | Red | Power from cooling, 24 Vac transformer |
| Rh | Red | Power from heat, 24 Vac transformer |
| C | Black/Blue | Common of 24 Vac transformer |
| W | White | Primary heat cell relay |
| E | Brown | Emergency heat relay |
| Y | Yellow | Primary cool call relay |
| Y2 | Yellow | Secondary cool call relay |
| G | Green | Fan relay |
| O | Orange | Change-over relay to cool relay |
| B | Blue | Change-over relay to heat relay |
| A | Heat and cool active to any relay | |
| L | Emergency heat active lamp | |
| X | System malfunction lamp | |
| P | Defrost control lamp |
References
| Reference | URL |
|---|---|
| How Air Conditioners Work | https://servicechampions.com/how-your-air-conditioner-works/ |
| AC Won't Start | https://www.youtube.com/watch?v=wzAA4dlp_70 |
| AC Capacitor Fail | https://www.youtube.com/watch?v=C82HvbvP08E |
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