# How to select an A/C compressor drive motor...?



## DIYguy (Sep 18, 2008)

booksix said:


> I am thinking I'm going to run a secondary motor to drive my a/c compressor. Possibly coupled inline (not belt driven) and using the a/c clutch signal to operate a relay to turn the motor on and off. How would I go about figuring out what motor would have enough power and would turn at the right speed for my application?


Hey Book,

I haven't got this far with mine.. but I have kept all the AC stuff in-tact on my truck, protecting for this option. For the little time I have considered method so far... I'm thinking that i will drive mine with a aux motor also, even though I have a tail shaft. This will help save the shaft for regen drive and tach gizmo. I've heard that some folks have had success with treadmill motors. I was thinking to mimic the lower ICE rpm range (ICE idle speeds work ok). Next would be to look up the torque requirement for the AC compressor. I would think that most of them are pretty similar... for standard cabin size and freon type. ... my only thoughts so far.

Question... if u r to couple in-line... will you couple motor shaft to clutch pulley then??

Cheers.


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## booksix (Aug 26, 2008)

So, perhaps look a the torque needed, then calculate the rpm and build a circuit that will run the motor and the needed voltage to achieve that rpm?

As far as coupling, I was thinking I'd ditch the compressor pulley/clutch and use a typical coupler. Then, the same signal that comes from the cars computer to activate the old a/c clutch can turn the motor on and off, achieving the same result with less losses. And I was going to run inline because I think it will be better than a side-by-side belt driven setup for space purposes


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