Arcing on connection to cap on Trane A/C compressor

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Last summer I replaced a cap on this '88 Trane unit when it stopped running. It was actually the 2nd time I'd replaced that cap. Once the cap was replaced it ran fine. Cooled the house off quick, not huge impact on the power bill given rate hikes over the years. Ran it a few times for heat briefly during the Winter, didn't notice any problems. Just now when I tried to fire it up on A/C again, no cooling. So, having gone through this drill twice before I immediately went to look at the cap. It's not bulging like the previous 2 were before but one of the spade connectors has severed from the wire and there's obvious arcing residue on the contacts and melting of the plastic fitting around the contacts the severed spade was attached to. On that side the contacts are also very rusted while the contacts on the other side are still shiny. I can also feel oil on the outside of the cap.
Not a big trick to get another cap and solder a spade connector back onto the wire, but I wonder what caused the arcing? The A/C ran like a champ when it was running last summer after the cap was replaced and I visually checked it a time or two over the next couple of months to see if I could see any issues, didn't see anything that caught my attention - but this makes 3 times in a couple of years I've had issues with that cap, albeit not the same identical issue at least from an eyeball standpoint.
I've had the cap mounted sideways, simply because the strap on the unit for the factory cap is oriented that way. Should it make any difference which direction the cap is oriented?
Thanks for all assistance and wisdom.
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muzician21 wrote:

Maybe the spade clip was not quite tight or the cap. is El cheapo Chinese stuff? Until you get another one with higher W.V rating (prefered), can't tell what happened. I don't like the sign of oil leak(?) Good luck.
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On Thu, 23 Feb 2012 16:00:41 -0800 (PST), muzician21

caps to fail, and now the connection has completely failed. I'd put on a new connector and a new cap and apply dialectric greese to the connections to seal them against corrosion.
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On 2/23/2012 6:00 PM, muzician21 wrote:

I just repaired one today for a long time customer. The original female 1/4" Faston connector slipped off the contactor because it was sprung, I simply used my needle nosed pliers to crimp it down a bit so it slipped tightly back on the male Faston connector on the contactor. Every Summer I wind up replacing a ton of Chinese capacitors in HVAC systems. I will always replace a 370 volt rated cap with one rated at 440 volts AC.
TDD
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The Daring Dufas wrote:

Same happened to my garage door travel limit switch on the screw drive track. I think connector(female) popped and sprung(due to vibration?) One night I came home and push the remote button and door tried to go down instead of going up. I disengaged the opener and had a quick look, found what happened. I always tighten them with needle nose pliers or hard to reach spot, I just solder the connector.
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On 2/23/2012 11:58 PM, Tony Hwang wrote:

Having the correct crimp tool is a necessity, I have a half dozen different types including one that crimps from four directions. ^_^
TDD
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Should not. Caps are not position sensetive.
Christopher A. Young Learn more about Jesus www.lds.org .
I've had the cap mounted sideways, simply because the strap on the unit for the factory cap is oriented that way. Should it make any difference which direction the cap is oriented?
Thanks for all assistance and wisdom.
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Its 24 years old.... did you expect it to last forever?? Your heating and cooling system runs 24/7..... You're in your car for *maybe* 1 hour a day.... are you driving a 24 year old car??
The R22 refrigerant that is in that system is rapidly going the way of the Dodo bird.... If you have to have it gassed up for the summer, get ready to pay 3 - 4 times what you paid last year.
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On 2/24/2012 7:20 AM, Steve wrote:

I wonder how many power spikes have hit that unit causing cumulative damage to the electrical components over 24 years? o_O
TDD
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wrote:

My AC is 38 years old and still running - and original caps

about 18 years ago.
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I replaced a 25-year-old unit, not because it broke but because it was breaking me. Old unit drew 19 amps and the new one only draws 9. Basically cut my cooling bill in half.
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wrote:

old one this spring for the same reason - and the "new parts" were free.
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On Feb 24, 1:11pm, snipped-for-privacy@snyder.on.ca wrote:

.
That is virtually unheard of, so, good for you and your a/c unit. Curious...what brand is it ? Around 1990, I came across an very old Westinghouse condensing unit with a pancake compressor in it which appeared to be 1950's and it was still cooling alright ; they wanted me to replace it to avoid a sudden breakdown and to save on electricity . It was a 3 ton capacity but the physical dimensions were approx. 5' wide x 5' long x 5.5' high . It was so heavy i had to cut it up into 3 pieces .
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On 2/25/2012 11:31 AM, snipped-for-privacy@gmail.com wrote:

Isn't is amazing how old very well made equipment keeps on working year after year? Several years ago, I repaired an old Carrier AC condenser a fellow bought back in the 70's. It was a high end unit with stainless steel fasteners and no rust on it anywhere. It had a factory installed sight glass, high and low pressure cutouts, anti short cycle timer and a two speed condenser fan. The only thing wrong with it was the fan quit working. Another tech told him he needed a new unit and wanted to install a cheap builders/contractor grade replacement condensing unit. I replaced the fan motor with a (not cheap) two speed motor and the old Carrier with the insulation blanket around the compressor hardly made a sound when the fan was running at low speed at night when the ambient temperature was low enough. The darn thing should run another 20 years without a problem. Yes, I know the new stuff is more efficient but the old guy didn't have thousands of dollars to shell out.
TDD
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On Sat, 25 Feb 2012 19:03:38 -0600, The Daring Dufas

having the gas checked about 18 years ago and having half a pound added, the only problem we've had was a bad thermostat connection (which was the real problem when I had the gas checked).
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On 2/25/2012 7:42 PM, snipped-for-privacy@snyder.on.ca wrote:

You're responding to the wrong poster but that's cool(no pun). ^_^
TDD
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There's a difference between selfish tech versus a customer service oriented tech. You are the finer of the two. The quality shows.
Christopher A. Young Learn more about Jesus www.lds.org .
a two speed condenser fan. The only thing wrong with it was the fan quit working. Another tech told him he needed a new unit and wanted to install a cheap builders/contractor grade replacement condensing unit. I replaced the fan motor with a (not cheap) two speed motor and the old Carrier with the insulation blanket around the compressor hardly made a sound when the fan was running at low speed at night when the ambient temperature was low enough. The darn thing should run another 20 years without a problem. Yes, I know the new stuff is more efficient but the old guy didn't have thousands of dollars to shell out.
TDD
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That's a pretty big compressor. Back in 90, were scrolls available? Or maybe rotary? Or did you have to put in a newer piston unit?
I bet the energy bill went down.
Christopher A. Young Learn more about Jesus www.lds.org .
Around 1990, I came across an very old Westinghouse condensing unit with a pancake compressor in it which appeared to be 1950's and it was still cooling alright ; they wanted me to replace it to avoid a sudden breakdown and to save on electricity . It was a 3 ton capacity but the physical dimensions were approx. 5' wide x 5' long x 5.5' high . It was so heavy i had to cut it up into 3 pieces .
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Moisture or rain isnt getting on the cap is it ? Could be large Bugs getting on the spade connections . Ive had that happen. Make sure the electrical compartment of the unit is sealed up tight to prevent Bugs and moisture getting in.
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solder wires directly to cap by using a pig tail
i repair machines for a living that draw high current, if you replace a switch its best to replace the terminals too
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