One leg of breaker trips

[randomtroll]

One leg of the 220V to my central AC trips after it runs
for about six minutes. This happened a few times in a
row. I turned it off, called an AC firm, their guy came
out a week later (how long I had to wait). It worked for
him. It continued to work for about five hours until
it started tripping the breaker again. I don't want to
pay for another service call at which nothing happens.

Suggestions?

[lakeman1234]

Could be a loose connection on the 220V at the unit, disconnect or breaker.

[edward301]

I would replace the braker, it may be the problem, and
is cheap to replace.

[re2ell]

Originally posted by randomtroll
One leg of the 220V to my central AC trips after it runs
for about six minutes. This happened a few times in a
row. I turned it off, called an AC firm, their guy came
out a week later (how long I had to wait). It worked for
him. It continued to work for about five hours until
it started tripping the breaker again. I don't want to
pay for another service call at which nothing happens.

Suggestions?

hmmmm, only one leg tripping? how do you know that just one leg is tripping?

another rat in the woodpile

at least call out someone who will diagnose your a/c! if it's tripping the breaker, there is a problem!

[AllTemp]

Originally posted by re2ell

Originally posted by randomtroll
One leg of the 220V to my central AC trips after it runs
for about six minutes. This happened a few times in a
row. I turned it off, called an AC firm, their guy came
out a week later (how long I had to wait). It worked for
him. It continued to work for about five hours until
it started tripping the breaker again. I don't want to
pay for another service call at which nothing happens.

Suggestions?

hmmmm, only one leg tripping? how do you know that just one leg is tripping?

another rat in the woodpile

at least call out someone who will diagnose your a/c! if it's tripping the breaker, there is a problem!

Maybe there isn't a problem with the AC at all.... Maybe it's just a worn out breaker...

[AllTemp]

Originally posted by AllTemp

Originally posted by re2ell

Originally posted by randomtroll
One leg of the 220V to my central AC trips after it runs
for about six minutes. This happened a few times in a
row. I turned it off, called an AC firm, their guy came
out a week later (how long I had to wait). It worked for
him. It continued to work for about five hours until
it started tripping the breaker again. I don't want to
pay for another service call at which nothing happens.

Suggestions?

hmmmm, only one leg tripping? how do you know that just one leg is tripping?

another rat in the woodpile

at least call out someone who will diagnose your a/c! if it's tripping the breaker, there is a problem!

Maybe there isn't a problem with the AC at all.... Maybe it's just a worn out breaker...

If you've a clamp type amp probe check and see what the current is at the time it trips...

Breakers weaken over time as do fuses...

[cem-bsee]

ALL circuit breakers should be exercised at least once per year, twice is better. Because they have mechanical linkage which may corrode. This also helps to reseat the elec contacts.

I do mine just after New Years & Jul4 -- when stores are open -- just in case.

"Any breaker which has interrupted a severe fault shall be inspected by a qualified technician before returned to service."

for the subject breaker tripping: the internal contacts or linkage may be bad, the external connectors may be loose. or, a compressor winding may be going -- now having a high resistance fault -- or _____.

[Toolpusher]

Are you running the a/c with 2 single pole breakers ?

Not that it won't work, but I'd switch it out to a double pole. Have your guy check the connections.

[the dangling wrangler]

Cond. fan motor?

[wink]

I'LL MAKE IT SHORT FOR YOU,START LOOKING FOR ANOTHER CONDENSER
AND SAVE MONEY.

[hillbilly tech]

No i wouldnt start looking for another cond. until i had to,get somebody that knows there stuff and figure out whats going on,sounds like loose wire or bad breaker to me.Check amp draw when it kicks off is a must though.

[Jultzya]

Originally posted by re2ell
hmmmm, only one leg tripping? how do you know that just one leg is tripping?

Fused disconnect ?

[randomtroll]

I know that one leg of the breaker is tripping because it
has separate breakers for each leg; only one trips.

I already called a licensed AC contractor who came out and
found it working, then left without doing anything other
than billing me.

I suspected a bad connection because on the contractor's
first visit he found one of the leads to the compressor
burnt off (it was routed over an adjacent contact and
had probably rubbed off its insulation) and re-wired it
in such a way that it may not have made a good connection.

I repaired the connections to the compressor and it has
worked since. Had it not, I would have replaced the
breaker. Wink's suggestion to save money by looking for
a new compressor first would have cost me.

[re2ell]

Originally posted by randomtroll
I know that one leg of the breaker is tripping because it
has separate breakers for each leg; only one trips.



perhaps that is the problem, you have 2-single pole breakers (each designed to protect 120v. circuits) protecting a 230v. apparatus. 230v. circuits are to be protected by a double pole breaker, (such as, if one leg is over-amped, both legs will trip) this matter is covered in the NEC. double pole breakers are available specifically designed for refrigeration machines, i'd call a qualified hvac contractor or electrician to bring your electrical service up-to-date.

[re2ell]

Originally posted by Jultzya

Originally posted by re2ell
hmmmm, only one leg tripping? how do you know that just one leg is tripping?

Fused disconnect ?


got me good on that one!!!!

and shalt have to keep a keen eye out before i speaketh and leave no stone unturned.

[mdman]

If one leg is triping it may be an asymetrical fault i.e. phase to ground potential. Place your clamp meter around both legs, any measured current is to ground. Anything measurable is usually too much unless your using a high gain AEMC3711 Ground resistance meter and mA clamp, but that will set you back $2100.

The faut is one the leg with more current. This is quite rare though. I hope I said that right.

[cem-bsee]

using two or more sgl ph breakers on a multiphase circuit is illegal and hazardous!!!!

at the least, all must be ganged together at the trip handles --
best to use 2pole for 230v, or 3p for 3phase.