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ELECTRICAL TROUBLESHOOTING CHART - COOLING
9K BTU, 12K BTU, & 18K BTU
NO COOLING OPERATION
Compressor runs but Blower/Fan doesn't
Yes
24V at
control wiring?
Yes
Is Line Voltage present
at Motor Leads?
Yes
Check Capacitor, is
Capacitor Good?
Yes
Motor should run
No
No
No
No
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| Before continuing |
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| check for Error |
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| Insure that Fuses |
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| Codes, see |
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| are good and/or that |
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| electronics control |
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| Circuit Breakers are |
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| diagnostics and |
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| on and voltage is 208/230 |
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| test mode, page 15 |
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| O.K. |
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| Set thermostat to |
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| Nothing operates, |
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| "Cool," and the Temp. |
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| entire system |
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| below the present |
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| appears dead |
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| Room Temp. |
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| O.K. | No |
| Yes |
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| Line voltage present |
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| Compressor and Fan |
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| Fan runs but |
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| Motor should now |
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| at the Transformer |
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| Primary | No |
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| Compressor doesn't | No |
| operate |
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| Yes |
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| Yes |
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| Yes |
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| 24 Volts at |
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| See Refrigerant Circuit |
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| “R” Terminal on board |
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| No |
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| diagnosis if unit still is |
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| not cooling properly |
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| Yes |
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| 24 Volts present at |
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| Y terminals on | No |
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| Yes |
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| 208/230 Volts present |
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| Defective |
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| at #1 relay on board? | No |
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| defective control wiring |
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| or transformer |
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| Yes |
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| No |
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| Problems indicated |
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| in Blower Relay |
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| of board |
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| Supply Circuit |
| Is Locked Rotor | ||
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| problems, loose |
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| Connections, or bad |
| Voltage a minimum of | ||
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| Relays/Board | 197 Volts? | |||
| Replace Capacitor |
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| Yes |
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| Replace Capacitor |
| Are Capacitor and (if | |||
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| and/or Start Assist |
| so equipped) Start | ||
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| Device | No | Assist good? | ||
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| Possible motor |
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| Yes |
| problem indicated. |
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| Check motor |
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| thoroughly |
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| Allow ample time |
| Have System | |||
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| for pressures to | No | Pressures Equalized? | ||
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| equalize |
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| Yes |
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| Possible Compressor |
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| problem indicated. |
| Compressor should | ||
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| See Compressor |
| run | ||
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| Checks |
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Check Supply Circuit’s jumper at transformer. If okay, replace board
Problems indicated with
Control Transformer replace board
Problems indicated with
Room Thermostat or
Control Wiring
Replace board
Yes
Compressor and fan
motor should now
operate
Yes
See Refrigerant
Circuit Diagnosis if
unit still is not cooling
properly
40