I am running my window air conditioner on a 20 amp line run directly
to the breaker box. It runs fine for quite a while, through numerous
cycles, then trips the circuit when restarting itself. I am not very
knowlefdgeable in AC, but it seems to me the thermostat is shutting
off the compressor and trying to turn it back on too soon (about a
minute). Does this sound like a defective thermostat or is some other
circuitry involved?
Thanks,
kkri

In article . com, wrote:
I am running my window air conditioner on a 20 amp line run directly
to the breaker box. It runs fine for quite a while, through numerous
cycles, then trips the circuit when restarting itself. I am not very
knowlefdgeable in AC, but it seems to me the thermostat is shutting
off the compressor and trying to turn it back on too soon (about a
minute). Does this sound like a defective thermostat or is some other
circuitry involved?

Sounds to me more like the A/C has been loading the circuit too much for too
long, and causing the breaker to trip from overload.

What is the amperage rating on the nameplate of the A/C ?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Jun 5, 5:39 pm, (Doug Miller) wrote:
In article . com, wrote:
I am running my window air conditioner on a 20 amp line run directly
to the breaker box. It runs fine for quite a while, through numerous
cycles, then trips the circuit when restarting itself. I am not very
knowlefdgeable in AC, but it seems to me the thermostat is shutting
off the compressor and trying to turn it back on too soon (about a
minute). Does this sound like a defective thermostat or is some other
circuitry involved?

Sounds to me more like the A/C has been loading the circuit too much for too
long, and causing the breaker to trip from overload.

What is the amperage rating on the nameplate of the A/C ?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.


I agree. If the AC has only been off for a minute or two, there is
residual pressure that the compressor has to overcome. Even if the
nominal current draw for the AC is under 20 amps, the start surge is
likely higher, and that can cause a trip.

In addition, if you are plugging it in some distance away from the
circuit breaker, that may be related.
(I'm not sure why, exactly. I have a compressor I can run in my garage
on a 20 amp circuit with no problem. But if I plug it in to the
outside 20 amp circuit, it tries to start but is sluggish, and trips
in about 3 seconds. I dunno why. I didn't have anything else running
on the outside circuit.)

On 5 Jun, 20:39, (Doug Miller) wrote:
In article . com, wrote:
I am running my window air conditioner on a 20 amp line run directly
to the breaker box. It runs fine for quite a while, through numerous
cycles, thentripsthecircuitwhen restarting itself. I am not very
knowlefdgeable in AC, but it seems to me the thermostat is shutting
off the compressor and trying to turn it back on too soon (about a
minute). Does this sound like a defective thermostat or is some other
circuitry involved?

Sounds to me more like the A/C has been loading thecircuittoo much for too
long, and causing the breaker to trip from overload.

What is the amperage rating on the nameplate of the A/C ?

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

It only requires 15 amps.

kkri

In article .com, wrote:
On 5 Jun, 20:39, (Doug Miller) wrote:
In article . com,
wrote:
I am running my window air conditioner on a 20 amp line run directly
to the breaker box. It runs fine for quite a while, through numerous
cycles, thentripsthecircuitwhen restarting itself. I am not very
knowlefdgeable in AC, but it seems to me the thermostat is shutting
off the compressor and trying to turn it back on too soon (about a
minute). Does this sound like a defective thermostat or is some other
circuitry involved?

Sounds to me more like the A/C has been loading thecircuittoo much for too
long, and causing the breaker to trip from overload.

What is the amperage rating on the nameplate of the A/C ?

It only requires 15 amps.

Well, you're getting close to the maximum continuous load allowed by the
electrical code on a 20A circuit. (Continuous load is defined as maximum
current for three hours or more, and is limited by Code to 80% of the
circuit's rating, or 16A in this case.)

I think the first thing I'd try is a new 20A circuit breaker. They're cheap,
and they do wear out -- particularly if they are repeatedly loaded heavily
enough to make them trip. DO NOT even think about replacing the 20A breaker
with a 30A or higher unit. That is a serious fire hazard.

With the breaker OFF, check the connections at the receptacle and at the
breaker. Make sure they're snug, with no evidence of corrosion. Replace any
corroded parts.

Take the A/C unit cover off, and clean it inside. A buildup of dust and crud
on the blower can cause it to work harder and draw more current than it's
supposed to.

If none of that takes care of the problem, it might be time to rewire the
circuit with #10 copper wire and use a 30A breaker. DO NOT use a 30A breaker
on your existing wiring. It isn't safe.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On 6 Jun, 08:14, (Doug Miller) wrote:
In article .com, wrote:
On 5 Jun, 20:39, (Doug Miller) wrote:
In article . com,
wrote:
I am running my window air conditioner on a 20 amp line run directly
to the breaker box. It runs fine for quite a while, through numerous
cycles, thentripsthecircuitwhen restarting itself. I am not very
knowlefdgeable in AC, but it seems to me the thermostat is shutting
off the compressor and trying to turn it back on too soon (about a
minute). Does this sound like a defective thermostat or is some other
circuitry involved?

Sounds to me more like the A/C has been loading thecircuittoo much for too
long, and causing the breaker to trip from overload.

What is the amperage rating on the nameplate of the A/C ?
It only requires 15 amps.

Well, you're getting close to the maximum continuous load allowed by the
electrical code on a 20Acircuit. (Continuous load is defined as maximum
current for three hours or more, and is limited by Code to 80% of thecircuit'srating, or 16A in this case.)

I think the first thing I'd try is a new 20Acircuitbreaker. They're cheap,
and they do wear out -- particularly if they are repeatedly loaded heavily
enough to make them trip. DO NOT even think about replacing the 20A breaker
with a 30A or higher unit. That is a serious fire hazard.

With the breaker OFF, check the connections at the receptacle and at the
breaker. Make sure they're snug, with no evidence of corrosion. Replace any
corroded parts.

Take the A/C unit cover off, and clean it inside. A buildup of dust and crud
on the blower can cause it to work harder and draw more current than it's
supposed to.

If none of that takes care of the problem, it might be time to rewire thecircuitwith #10 copper wire and use a 30A breaker. DO NOT use a 30A breaker
on your existing wiring. It isn't safe.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.- Hide quoted text -

- Show quoted text -

Thanks, Doug, but let me ask why a 15 amp device would require a 30
amp circuit? I'll get a new 20 amp breaker and see what happens.

kkri

In article .com, wrote:
On 6 Jun, 08:14, (Doug Miller) wrote:
In article .com,
wrote:
On 5 Jun, 20:39, (Doug Miller) wrote:
In article . com,
wrote:
I am running my window air conditioner on a 20 amp line run directly
to the breaker box. It runs fine for quite a while, through numerous
cycles, thentripsthecircuitwhen restarting itself. I am not very
knowlefdgeable in AC, but it seems to me the thermostat is shutting
off the compressor and trying to turn it back on too soon (about a
minute). Does this sound like a defective thermostat or is some other
circuitry involved?

Sounds to me more like the A/C has been loading thecircuittoo much for too
long, and causing the breaker to trip from overload.

What is the amperage rating on the nameplate of the A/C ?
It only requires 15 amps.

Well, you're getting close to the maximum continuous load allowed by the
electrical code on a 20Acircuit. (Continuous load is defined as maximum
current for three hours or more, and is limited by Code to 80% of
thecircuit'srating, or 16A in this case.)

I think the first thing I'd try is a new 20Acircuitbreaker. They're cheap,
and they do wear out -- particularly if they are repeatedly loaded heavily
enough to make them trip. DO NOT even think about replacing the 20A breaker
with a 30A or higher unit. That is a serious fire hazard.

With the breaker OFF, check the connections at the receptacle and at the
breaker. Make sure they're snug, with no evidence of corrosion. Replace any
corroded parts.

Take the A/C unit cover off, and clean it inside. A buildup of dust and crud
on the blower can cause it to work harder and draw more current than it's
supposed to.

If none of that takes care of the problem, it might be time to rewire
thecircuitwith #10 copper wire and use a 30A breaker. DO NOT use a 30A breaker
on your existing wiring. It isn't safe.

Thanks, Doug, but let me ask why a 15 amp device would require a 30
amp circuit? I'll get a new 20 amp breaker and see what happens.

The maximum continuous load allowed on a 20A circuit is 16A. Your A/C unit is
rated at 94% of that.

As I noted above, dust and crud on the blower can cause it to work harder and
draw more current. So can a clogged filter.

You only have to be drawing seven percent more current than the unit is rated
at, before you've exceeded the allowable capacity of a 20A circuit for a
continuous load. A 24A circuit would be fine, but they don't make 24A
breakers. The next step up is 30A.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.