Intro: Temporary A/C Compressor Fan
Let me tell you how I became my 76 year old wife's hero today (Aug/16/16)
Our home's central air compressor's fan started making a noise and the motor got terribly hot, indicating to me a bearing was failing. It was Sunday morning, with no chance of buying a motor to replace mine until Monday morning. The temperature was expected to be 100F+.
Step 1: The Problem
The compressor produces heat which must be cooled for the air conditioner to work. This motor turned a large round 3 blades fan. I had an old "squirrel cage" fan that would do the job temporarily if I could just mount it inside the unit and run it continuously by plugging it into 120 vac. See photo #2.
Step 2: The Temporary Solution Step #1
TURN OFF THE 220VAC BREAKER SWITCH TO THE A/C UNIT.
I remove the grill on top of the unit, removed the motor. I made a wiring diagram of the wires being removed so that I could hook up the new motor, I then removed the round blade from the motor shaft using a brass punch and hammer. Don't beat on a steel shaft with a steel hammer or punch or you will bend the shaft or the part that's mounted on the shaft, ruining the parts.
Step 3: Temporary Solution Step #2
I now had a large round opening in the top of the unit and needed to set the squirrel cage fan down into this hole with the exhaust pointing up to pull outside air through the condenser fan and blow the hot air out the top. There was just one problem.: This round hole must be sealed up completely around the fan. I accomplished this by screwing 4 pieces of particle board and 2 short 2 x 4's around the fan's frame. I ran a heavy duty extension cord through the kitchen window and plugged it into 120 vac and stuffed a towel under the window opening to block the cold from going out and the heat from coming in. I plugged the fan into the cord. It came on and seemed to deliver LOTS of air. I turned the A/C back on. Now the exhausting air was hot, as it should be. The fan must now run continuously, but that was okay. The A/C ran as it normally did and kept the house cool until I installed the new motor Tuesday morning. I didn't want to try replacing it late Monday because if something went wrong, we would spend a miserably hot Monday night. By replacing it Tuesday morning, I would have several hours to run back to the motor supply shop. The new motor works great and everything is back to normal. The new motor cost $155.00.
If you try anything this unorthodox, flip off the breaker box before you start on it. The compressor & most of the wiring is 220 vac & it's lethal.
Step 4: The New Motor Installed
The compressor unit looks exactly like it did before I replaced the motor. Sorry I didn't take many photos, but I didn't plan on publishing this until later I decided this information might help someone survive the heat. Don't try this unless you have a lot of mechanical history and a little electrical experience. The wiring must be re-attached EXACTLY as it was before. Any changes will probably burn up the motor and wiring, costing hundreds of dollars.
Air conditioner repairmen are terribly busy this time of year in Oklahoma. Getting one to work on Sunday is impossible. And that's how I became my wife's hero.