220 VAC A/C condenser fan motor at 120 VAC?

I have just wired up a used A/C 1/4 hp condenser fan motor with 110 VAC.

It starts up easily and runs quietly.

I am using it to blow the air from one side of a duplex attic into the other side, thereby cooling both attics.

The motor was designed for vertical shaft installation and I am using it horizontally.

Is there any danger in running it at 1/2 the voltage and in the horizontal orientation?

Thanks

Reply to
stu
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Running the motor at half voltage shouldn't pose a problem. 30 years ago we frequently did this to fan motors that were used in computer mainframes when it wasn't necessary to provide full cooling capacity and we never had a problem with them. If the fan moves enough air to satisfy you, then there shouldn't be an electrical problem with it. The bearings, however, may fail after a few years of use because they were really designed to be used with the shaft in a vertical plane and not designed to handle a significant side load.

Reply to
Charley

Charlie,

Many thanks. Nothing like experience to answer a question. There are many naysayers out there.

A note* This motor has a run capacitor and AFAIK it might help keep the current down a bit.

I positioned the oil inlet for ease of lubing. If I oil it twice a year, it might help the bearings.

What size motors were used in the main frame cooling fans?

Reply to
stu

Now you're pushing it. My memory isn't that good for something that I did 30 years ago.

They were double shaft motors with a squirrel cage fan on each output shaft. They had capacitors, and the motor cases were about 3" dia and 5" long, and they were painted black, but that's about all that I can remember about them.

Reply to
Charley

Many 220 volt appliances have internal 110 volt accessories. Are you sure that the motor is 220 volt? I have run capacitor start motors on lower voltage and they would not run correctly. The motor may only been running on 1 leg of the 2-110 volt lines coming in to the condenser/compressor.

Now, considering what you are doing, I did a similar set up in my attic about 20 years ago and ran the fan for 10 years. I found that the fan had no measurable effect on my electricity bill nor did the attic temperature drop. My electricity usage during the summer basically remained the same with the fan not running all day long. An expert in the Houston area addressed this once and indicated that the cooling savings was off set by the expense of running the fan. With my findings I totally agree. The motor I used was designed to be mounted facing up on a roof top and I had it mounted vertically, it never wore out.

Reply to
Leon

The motor plate reads 220 VAC. There is no 110 VAC connection.

This house in SE Florida has a steel roof and you can 'sense' the heat coming from the attic.

Time will tell whether the extra fan power will pay for itself.

However if the heat 'sense' is diminished, I would consider it a success.

5 seconds of holding my head in the attic at 2 PM is all the testing necessary to judge the effectiveness of forced air cooling. So far, it feels much cooler.

BTW The fan is controlled by a thermostat.

Reply to
stu

Well my attic seemed to be a bit lest stagnent when the fan was on but it never really lowered the temperature. I have an amuminum roof and my fan was also on a thermostat. The thermostat was set on 95 degrees and more often than not would run 24 hours a day during hte summer. Only in late September or after a cold front did I ever notice that it was not still running from the night before.

Good Luck.

Reply to
Leon

95 degrees 24 hours a day? And they say that FL is hot.

I will do an experiment. Leave the fan off till noon and measure the temp. Run it for an hour and measure again.

Did you run a 220 VAC fan on 120 VAC?

Reply to
stu

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