I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the
unit started right up. It will run for about 45 minutes and cools
fine. Then it trips the breaker. It cools fine while it is running.
The compressor already has a hard start kit on it. I have a couple of
questions

How can I determine weather the condenser fan or the compressor is
causing the breaker to trip?

Will a dirty condenser /debris or refrigerant charge contribute to the
breaker tripping?

What should I check from here?

Thanks for any help

komobu wrote:
I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the
unit started right up. It will run for about 45 minutes and cools
fine. Then it trips the breaker. It cools fine while it is running.
The compressor already has a hard start kit on it. I have a couple of
questions

How can I determine weather the condenser fan or the compressor is
causing the breaker to trip?

Will a dirty condenser /debris or refrigerant charge contribute to the
breaker tripping?

What should I check from here?

Thanks for any help

A similar thing happened to me. My son's neighbor, a midnight A/C
technician, diagnosed the problem in a nonce.

CAREFULLY put a finger on the breaker (side of the breaker is best). If the
breaker's warm, replace it.

$15 at the box store and everything is cool.

On Aug 10, 8:16*am, "HeyBub" wrote:
komobu wrote:
I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the
unit started right up. It will run for about 45 minutes and cools
fine. Then it trips the breaker. It cools fine while it is running.
The compressor already has a hard start kit on it. I have a couple of
questions

How can I determine weather the condenser fan or the compressor is
causing the breaker to trip?

Measure the current they are drawing. Also make sure the breaker
is sized correctly.





Will a dirty condenser /debris or refrigerant charge contribute to the
breaker tripping?

What should I check from here?

Thanks for any help

A similar thing happened to me. My son's neighbor, a midnight A/C
technician, diagnosed the problem in a nonce.

CAREFULLY put a finger on the breaker (side of the breaker is best). If the
breaker's warm, replace it.

$15 at the box store and everything is cool.- Hide quoted text -

- Show quoted text -

I'd be thinking to check current draw, while the unit is
running. Yes, a dirty condensor or improper refrigerant
charge can run the amperage up. You may also have a weak
breaker.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"komobu" wrote in message
...
I have a rather old central ac unit. It wasn't working at
all and it
looked like the contactor was bad. I replaced the contactor
and the
unit started right up. It will run for about 45 minutes and
cools
fine. Then it trips the breaker. It cools fine while it is
running.
The compressor already has a hard start kit on it. I have a
couple of
questions

How can I determine weather the condenser fan or the
compressor is
causing the breaker to trip?

Will a dirty condenser /debris or refrigerant charge
contribute to the
breaker tripping?

What should I check from here?

Thanks for any help

On Aug 10, 7:52*am, komobu wrote:
I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the
unit started right up. It will run for about 45 minutes and cools
fine. Then it trips the breaker. It cools fine while it is running.
The compressor already has a hard start kit on it. I have a couple of
questions

*How can I determine weather the condenser fan or the compressor is
causing the breaker to trip?

Will a dirty condenser /debris or refrigerant charge contribute to the
breaker tripping?

What should I check from here?

Thanks for any help

When ever I'm working on mine I also clean out the debris.

I'd start by replacing the breaker. They get weak with age and
multiple trips. Then they trip at less than the rated current. I'd
also check and tighten ALL the connections between the breaker and the
compressor.

The fan motor is typically a small fraction of the current draw. The
compressor is the bulk of it.

A low charge can cause problems. If it cools ok when running then
it's probably fine. I assume you don't have gauges. The old school
technique is the big copper pipe, which is the return, should feel
like a beer can just out the fridge where it goes into the outside
unit after it's been running for a little while.

komobu wrote:
I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the
unit started right up. It will run for about 45 minutes and cools
fine. Then it trips the breaker. It cools fine while it is running.
The compressor already has a hard start kit on it. I have a couple of
questions

How can I determine weather the condenser fan or the compressor is
causing the breaker to trip?

Will a dirty condenser /debris or refrigerant charge contribute to the
breaker tripping?

What should I check from here?

Thanks for any help
Hi,
Capacitor checked?

"komobu" wrote in message
...
I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the
unit started right up. It will run for about 45 minutes and cools
fine. Then it trips the breaker. It cools fine while it is running.
The compressor already has a hard start kit on it. I have a couple of
questions

How can I determine weather the condenser fan or the compressor is
causing the breaker to trip?

Will a dirty condenser /debris or refrigerant charge contribute to the
breaker tripping?

What should I check from here?

Thanks for any help

Many good suggestions already made. Also make sure that the condenser fan is
always running when the compressor is. If the fan stops on internal
overload, the head pressure will soar and the compressor will also go out on
overload.

"komobu" wrote in message
I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the
unit started right up.

Thanks for any help

You already got some suggestions on possible problems, but I have another
route you may want to consider.

If that AC is very old, you may be able to replace it and save enough on
the electric bill to pay for most or all of it. Start thinking about it
while the AC is still running and you can take the time to get what you
really need at a good price. Maybe a fall or winter job rather than the
first hot day of next summer when prices will be higher.

On Aug 10, 8:37*pm, "A. Baum" wrote:
On Wed, 10 Aug 2011 04:52:33 -0700, komobu wrote:
I have a rather old central ac unit. It wasn't working at all and it
looked like the contactor was bad. I replaced the contactor and the unit
started right up. It will run for about 45 minutes and cools fine. Then
it trips the breaker. It cools fine while it is running. The compressor
already has a hard start kit on it. I have a couple of questions

*How can I determine weather the condenser fan or the compressor is
causing the breaker to trip?

Will a dirty condenser /debris or refrigerant charge contribute to the
breaker tripping?

What should I check from here?

Thanks for any help

Need a set of gages and an Amp Clamp. Or call someone who knows what they
are doing.- Hide quoted text -

- Show quoted text -

Baum is too negative, the earlier suggestions were all worthwhile
following/investigating.