Compressor short cycling Rudd, I think


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Old 06-06-09, 07:50 AM
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Compressor short cycling Rudd, I think

My outside AC unit has a humming sound with intermittent clicking when the power is turned on. When I first saw the problem, the motor in the fan unit was not running, and was very hot. I replaced it although it tested OK, no shorts, turned freely and no burnt smell, just hot as hell. The problem is still there and it sounds/feels like the noise is coming from the compressor. I have 240V on both sides of the relay unit and the contactor pulls closed when powered. Right after I replaced the motor the fan did run when power was turned on, but after a few minutes it stopped and the hum/click noise started again. I am thinking to change the capacitor just in case it is the problem. Can a bad capacitor give these symptons? Does somebody know how to test the capacitor? Otherwise if I have a compressor problem then I will call the service tech. Any help is appreciated. DON
 
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Old 06-06-09, 08:00 AM
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Replace the cap...its relatively cheap. Should have actually been done when the motor was replaced.
 
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Old 06-06-09, 10:32 AM
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The Rudd Awakening

I worked on one of these the other day. I installed a Turbo 200 capacitor, it fits perfectly in the hole where the cap goes and the metal plate isn't needed....a perfect fit!. Replace the contactor it may not be letting all the voltage across. You only nee a single pole contactor because one side of the contactor is a solid bar that goes across. I didn't have one so I used a 2 pole contactor and I jumped L1 to T1, this bypasses the current so that its always on, on that half of the circuit. Many companies do this as a low current crankcase heater. Make sure the coil is cleaned also, kill the power, pull the fan out and jack it side ways so you can wash the coil from the inside to the outside. Dont get the motor wet if at all possible. You'll need a gallon of simple green and rinse it off well. Oh, that Turbo 200 will do both caps, The compressor and the fan. Mine was a 3/45 MFD requirement. Read the fan motor to make sure you get the right MFD for your application. The Turbo 200 is a multitap multi capacitor. Tecs carry it in their vans because it has em all in one. The individual ones are much cheaper but there is no substitute for convienence. Plus it drops right into the Rudd hole they have drilled out in the control box.
 
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Old 06-08-09, 06:59 AM
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Thanks for the help. I also need a 45/3 capacitor. However I can so far only find 45/5 locally. I looked at the Turbo 200 on internet, and it only gives options for 2.5MF and 5MF. I can get the 45 OK, but how did you set up for the 3MF fan requirement?
 
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Old 06-08-09, 10:31 AM
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Buy a separate 3uf capacitor for the fan.
 
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Old 06-18-09, 07:53 PM
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the 3mfd

It has a separate post for the 3mfd. Its only about $30.00 for both if you buy two singles and stick them in the box and tape the heck out of the posts so that they dont short out on something. I circumvented the hassel using the Turbo 200 It drops right in and has all the jumpers with it and instructions with pictures in color...very easy to follow. I like easy!
 
 

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