A/c condensor buzzing symptoms


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Old 01-28-18, 05:50 PM
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A/c condensor buzzing symptoms

I have a Ruud/Rheem AC condenser maybe 8 years old. Last summer I noticed when it was running sometimes a really really loud buzzing sound would happen. If I went to the thermostat and turned off the unit and then turned it back on then the buzzing was gone. It happened a few times last summer but turning it off then on seemed to fix it. Any ideas? Could it be capacitor?
 
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Old 01-28-18, 06:03 PM
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Is it just a split A/C system.... cooling only.... or a heat pump system ?

A contactor can buzz and so can a reversing valve.
 
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Old 01-28-18, 06:13 PM
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It is a cooling only system
 
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Old 01-28-18, 06:39 PM
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when it happens, shut the breaker to the outdoor unit only and see if the noise stays.

it's not expensive to change a contactor, if it continues buzzing, that's what it is.
 
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Old 02-01-18, 10:54 AM
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Any help on finding a replacement for this contractor?
 
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Old 02-01-18, 01:55 PM
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From looking up the Siemens part number, it appears to be a 30Amp, single pole contactor. While there are many places you can purchase it, below is an Amazon link for the replacement.

https://www.amazon.com/Replacement-S.../dp/B00DZPHDCU
 
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Old 02-03-18, 10:15 AM
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Thank you for the help with this.
 
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Old 02-03-18, 10:43 AM
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Very helpful. I ended up going with this one. Do the wires set up the same way when I replace it ? https://www.amazon.com/Replacement-R.../dp/B0195UUWG2
 
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Old 02-03-18, 11:09 AM
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Your old contactor is labeled L1, L3 and T1 and T3.
The new one is labeled L1, L2 and T1, T2.

Just keep the incoming lines on the L side and the push-on connections to the unit on the T side. The two side wires.... yellow and brown.... can go on either side.

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Old 02-03-18, 11:12 AM
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It may or may not hookup the same as the old one. The heavy wires are the 240VAC wires. One pair, typically going to the L1 & L2 terminals on the contactor is the 240VAC input. The T1 & T2 terminals are the output of the contactor and go to the compressor and fan motor. The thinner wires are the 24VAC control signal (from the thermostat) and typically connect to side terminals on the contactor. The control signal terminals may be one on each side or both on the same side of the contactor. Since the control voltage is AC, there is no polarity (doesn't matter which thin wire goes to which terminal).

Before you begin, be certain to disconnect the power from the outside unit (should be an electrical disconnect located near the outside unit). Draw yourself a wiring diagram of how the old contactor is wired and take a picture of it as well. Once you've documented how the old one is wired, wire the new on in a similar fashion. You'll find several instructional videos on YouTube.
 
 

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