condenser keeps blowing start cap

[bigjohnsons34]

I have a customer who has a 5 ton carrier condenser, in the last couple of weeks it has blown ( totally destroyed ) 3 start capacitors. the compressor won't start without the cap, but with it installed it starts up and runs perfectly. I've replaced the cap and the relay. any suggestions ??? thanks

[kls-ccc]

My experience has been that if you lose multiple start caps that the relay is usually bad. If you replaced the relay was it rated properly for the compressor, and did it get mounted properly? If a start cap goes it is because it is in the circuit to long which means the relay didn't drop it out fast enough. The only other thing is how long does it take the compressor to start?

[bigjohnsons34]

With the cap installed, the compressor starts up immediately. one of the caps that i installed was a kick start and came with its own relay, the other one was separate cap and relay

[kls-ccc]

Just for clarification, you didn't say did the relay get mounted according to the instructions, they are position sensitive? How long do these caps last, hours, days ...?
Do you have a logger that you can put on the unit to see what happens when you aren't there? Have you checked the drop out voltage on the relay? Is it the same every time?

[bigjohnsons34]

when i replaced the cap and relay separately, I mounted the relay in the same holes that the other one came out, to be honest I didn't think this made mush of a difference. I'm not sure how long it lasted for because my customer was never there when I replaced the cap, he would just call a couple of days later and ask when i was getting there to fix the problem or if the part came in, not knowing that it was working when i left. and no i do not have a logger and Io didn't check for drop out voltage

[subway]

Is this a carrier two speed compressor (Bristol) with potential relay?

[bigjohnsons34]

sounds about right. i know it's a high efficient unit as of 5 or so years ago, it has a 2 stage compressor, not sure what kind, and it does have a potential relay. why what have you know ???

[the dangling wrangler]

sounds about right. i know it's a high efficient unit as of 5 or so years ago, it has a 2 stage compressor, not sure what kind, and it does have a potential relay. why what have you know ???

Something ain't right here. You're working on a unit, and don't even know what you're working on?
Sounding like DIY to me.

[n-e-w Jerz!]

Something ain't right here. You're working on a unit, and don't even know what you're working on?
Sounding like DIY to me.

not only that, wouldn't you call service support of the manufacturer to verify the multiple components of the system? go thru the wiring using the wiring schematic to insure every thing is in the right place? at least do a winding to winding test on the compressor to insure a partial short does not exist? something ain't right is right!

[bigjohnsons34]

it's been a customer of mine for years, the first time it blew i didn't go out there myself. i didn't install the units, i just service them . He gets me some work so i try not to charge him when i go out there, and he's done some favors for me on my house. so to answer your question, when i was there i didn't think it would be a reoccurring problem, so i didn't put to much effort into the problem. I've replaced tons of capacitors and never had this problem, i actually thought the problem was solved til he called me today wondering if the part ever came in, so i thought i would pick your brain before i went back tomorrow morning.

[bigjohnsons34]

he has the same 3 units side by side, so i cross checked the wiring and everything is spot on. but no i didn't check the windings but than again i never had a problem with start caps blowing

[the dangling wrangler]

I'm just rattelin' your cage 34. It really isn't any of my business.

[bigjohnsons34]

i know, it just sucks cause these problem always happen on jobs that your not making any money on

[junkhound]

No disrespect BJ34, but I agree with dw. --- sumptin aint right.

This site let me register as a pro, so I respect their perogatives - lthough I have never done anything for hire residential in my life; just a DShet engineer who has done 200 kW cabin systems for airplanes and designed HP and AC (military calls them ECS) from the ground up for missile silos, but the mods here let me in technically 'cause I respect their perogatives.

This thread though makes me wonder, that if you are truly in the residential HVAC business, as a service to your customers your really need to go to some electrical classes, your basic understanding of motors is woefully lacking. Look at 'klc's comments, he knows the questions to ask! You should have used that type analysis immediatley on your 'service call', it should have been as basic to you as tying your shoes!!!

BTW; I have the same exact screen name at , if you want diy answers, go there... You will get a lot of BS and sometimes bad advise also! But I will try to tell youthere where to go to find the education you need....\

btw2 start with the training sections on this site!

[the dangling wrangler]

i know, it just sucks cause these problem always happen on jobs that your not making any money on

Well, that's life.
Next visit, get the model & serial numbers off the units and compressors, then get the factory relays & caps. Can't go wrong that way.

[junkhound]

Hey DW, I forgot to tell him that! Even more basic than Ohm's law!

Next visit, get the model & serial numbers off the units and compressors, then get the factory relays & caps. Can't go wrong that way.

[the dangling wrangler]

Hey DW, I forgot to tell him that! Even more basic than Ohm's law!

Next visit, get the model & serial numbers off the units and compressors, then get the factory relays & caps. Can't go wrong that way.

OK. I'll let ya slide this one time only.

[tipsrfine]

I'm only 4 years into my career but I have to post to get pro member status. I would go back and after doing what the pro's hear have said, I would take an amp draw at start-up and make sure the start cap is in fact dropping out of the circuit. If that checks out, then I would check any pressure switches or anything else that would cause the unit to cycle on and off continuously. That would explain a start cap blowing up because it is not a run cap and does not have the metal housing or oil inside. It will burn up if left in the circuit durring run or if it consistently is brought in the circuit too fast & too many times.

[beenthere]

If your in the trade, get your post count up to 15, and apply for Pro Membership.
Then use this link Apply for Pro Membership (http://hvac-talk.com/vbb/showthread.php?threadid=116113)

Once accepted, you have access to the pro tech forums. Where you can ask and get answers to technical questions.

Plus, you also have access to the Pro Educational Forums.

All of it is free.

[tipsrfine]

Thanks Beenthere. Learning and getting access to those technical learning sites is really what I'm after, but I'm keeping an eye out for post where I think I may have something to offer. I'm not really sure if everytime I reply is a post or only when I reply to a new post counts-or do I have to start a new thread?

[the dangling wrangler]

Thanks Beenthere. Learning and getting access to those technical learning sites is really what I'm after, but I'm keeping an eye out for post where I think I may have something to offer. I'm not really sure if everytime I reply is a post or only when I reply to a new post counts-or do I have to start a new thread?

Don't really matter. You're almost there. Reply to this and find out.

Look in the general section ,for the world famous 9mm thread. That should put you over the top.

[tipsrfine]

You said to reply "to this" and I'd find out about my pro mem status. So I am and now I'm going to go look for the 9mm thread.

[the dangling wrangler]

You said to reply "to this" and I'd find out about my pro mem status. So I am and now I'm going to go look for the 9mm thread.

I meant about your post count.
The membership thing, takes a week or two to happen. First ya gotta have enough posts.
Then ya gotta work out what Twilli 's cut(bribe) will be,and the rest will fall into place.

[jdcoolj]

Did you check the electrical connections at the compressor terminals and the condition of the the contactor contacts on both contactors? Also i would recommend megging the compressor.

[beenthere]

All post count.