Portable AC keeps tripping breaker

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Kennedy
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Portable AC keeps tripping breaker

Post by Kennedy »

There is a portable AC unit that was recently plugged into an outlet in a new house. The family is reporting that the breaker trips when the AC is on. They further report that there is always a tv running on the same circuit, and they haven't tried the AC without the tv to see if the breaker trips.

I looked at the back of the AC, and it says it is 10.4 amps. I then looked at the breaker box, and that circuit breaker says "10 KA."

I'm assuming this means that the circuit will accommodate a maximum of 10 amps? I literally know nothing about electricity, so I'm sure this is an elementary question for many here.

Is there any work-around for how this particular unit can be used?
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unclescrooge
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Re: Portable AC keeps tripping breaker

Post by unclescrooge »

Wow, that's a serious portable ac unit.

I think they need to downsize to a smaller unit that draws less current.
PVW
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Re: Portable AC keeps tripping breaker

Post by PVW »

Without an electrician, the only acceptable solution is to either reduce the load on the circuit breaker or plug the AC unit into an outlet on a different circuit breaker.
GaryA505
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Re: Portable AC keeps tripping breaker

Post by GaryA505 »

Modern TVs don't use that much juice, so it's just the AC unit.
Turbo29
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Re: Portable AC keeps tripping breaker

Post by Turbo29 »

Kennedy wrote: Thu Apr 16, 2020 1:50 pm There is a portable AC unit that was recently plugged into an outlet in a new house.


Where do they build new houses that have less than a 15amp breaker on any circuit?
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ponyboy
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Re: Portable AC keeps tripping breaker

Post by ponyboy »

Turbo29 wrote: Thu Apr 16, 2020 1:58 pm
Kennedy wrote: Thu Apr 16, 2020 1:50 pm There is a portable AC unit that was recently plugged into an outlet in a new house.


Where do they build new houses that have less than a 15amp breaker on any circuit?
My house was built in the late 90's and my lowest is 20amp. Who in their right mind would still use 15amp? Even for lights, id still go 20.
Swivelguy
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Re: Portable AC keeps tripping breaker

Post by Swivelguy »

"10 KA" is probably the interrupting rating of the breaker, not the tripping current. There's probably another number on it labeled either with just an A or with no letters at all, which is the tripping current. The breaker will interrupt the circuit if the current exceeds the tripping current. The 10 KA means that the breaker will survive a momentary current spike up to a 10,000 amp current and interrupt it without damage to the breaker.

Assuming this is the U.S., It's unusual to have circuits in a house with an interrupting current of less than 20 A, unless perhaps the house is very old. It could be that you do in fact have a 10 A breaker, which explains it tripping when the A/C runs. If the breaker is a more typical 20A or 30A, then probably what is happening is that the A/C pulls 10.4 amps continuously while operating, but may draw several times that for a short period when the compressor is starting, and this is what is tripping the breaker. The surge current draw may or may not be listed in the specifications.

The owners should consult an electrician to determine if the wiring of the circuit is of a sufficient gauge that the breaker can be replaced with a larger tripping current, or if the wiring needs to be upgraded (and how feasible it is to do that).
megabad
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Re: Portable AC keeps tripping breaker

Post by megabad »

I would just buy a commercial grade 12 gauge extension cord rated for 15 amps or greater and put the unit on a different circuit. Be sure to use it properly and safely and temporarily. Sounds like your circuit is overloaded.
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David Jay
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Re: Portable AC keeps tripping breaker

Post by David Jay »

First troubleshooting step: plug it into another outlet on a different circuit (that will likely mean a room in the other side of the house).

If it trips in the new location, the air conditioner is not going to work without changing the electrical arrangement in this house [or the Air Con is defective].

If it doesn’t trip in the new location, change the circuit breaker in the first room. Even Brand new circuit breakers are sometimes “bad” out of the box.
Last edited by David Jay on Thu Apr 16, 2020 2:23 pm, edited 1 time in total.
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ralph124cf
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Re: Portable AC keeps tripping breaker

Post by ralph124cf »

Is this a rental house that you own?

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Sandtrap
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Re: Portable AC keeps tripping breaker

Post by Sandtrap »

Kennedy wrote: Thu Apr 16, 2020 1:50 pm There is a portable AC unit that was recently plugged into an outlet in a new house. The family is reporting that the breaker trips when the AC is on. They further report that there is always a tv running on the same circuit, and they haven't tried the AC without the tv to see if the breaker trips.

I looked at the back of the AC, and it says it is 10.4 amps. I then looked at the breaker box, and that circuit breaker says "10 KA."

I'm assuming this means that the circuit will accommodate a maximum of 10 amps? I literally know nothing about electricity, so I'm sure this is an elementary question for many here.

Is there any work-around for how this particular unit can be used?
KA is kiloamps. 1 KA = 1000 amps. 10 KA = 10,000 amps.
Not sure what you're looking at.
Household breakers for receptacles are 20 amps. some older lines, 15 amps. Depends on local code or NEC.
The label on the circuit breaker trip handle reads 15 or 20, etc. = amps.

If only the portable AC unit, then the circuit breaker shouldn't trip.
Try the AC unit on a normally higher amp circuit like a washing machine and see if it trips. Might be the A/C unit.
I've had portable A/C units in the past, also many of my tenants.

Average vacuum cleaners draw from 7-12 amps.

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quantAndHold
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Re: Portable AC keeps tripping breaker

Post by quantAndHold »

Unlikely that the TV is adding enough load to trip the breaker. Also unlikely that any circuit on any house built in the last 50 years is less than 15 amps. Step 1 would be to try the AC on a different circuit. If it works, get an electrician out. If it doesn’t work, the AC is probably defective.
Yes, I’m really that pedantic.
Topic Author
Kennedy
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Re: Portable AC keeps tripping breaker

Post by Kennedy »

Swivelguy wrote: Thu Apr 16, 2020 2:03 pm "10 KA" is probably the interrupting rating of the breaker, not the tripping current. There's probably another number on it labeled either with just an A or with no letters at all, which is the tripping current. The breaker will interrupt the circuit if the current exceeds the tripping current. The 10 KA means that the breaker will survive a momentary current spike up to a 10,000 amp current and interrupt it without damage to the breaker.

Assuming this is the U.S., It's unusual to have circuits in a house with an interrupting current of less than 20 A, unless perhaps the house is very old. It could be that you do in fact have a 10 A breaker, which explains it tripping when the A/C runs. If the breaker is a more typical 20A or 30A, then probably what is happening is that the A/C pulls 10.4 amps continuously while operating, but may draw several times that for a short period when the compressor is starting, and this is what is tripping the breaker. The surge current draw may or may not be listed in the specifications.

The owners should consult an electrician to determine if the wiring of the circuit is of a sufficient gauge that the breaker can be replaced with a larger tripping current, or if the wiring needs to be upgraded (and how feasible it is to do that).
OP here. You are right. I went out and looked at the box again, and the circuit in question as a "15" on it as well as the 10 KA. And you're also right in that the tenant reports the circuit trips when the compressor starts and not when just the fan is operating between cooling cycles.
renue74
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Re: Portable AC keeps tripping breaker

Post by renue74 »

Newer breaker boxes contain Arc Fault breakers, which often have more nuisance trips because of their sensitivity. That may be your issue.

Or you may need a larger 20 amp circuit...so you would need to reposition the A/C to test.

I live in the south and we put all receptacle circuits on 15 amp arc fault breakers and sometimes up to 10 or so receptacles in multiple rooms.

Best practices:

1.) Move the A/C unit to the laundry room and put it on the washer receptacle. The washer receptacle is a solo circuit just for the washer and it should be a 20 amp circuit. (Other potential 20 amp solo circuits in your house: microwave, refrigerator, dishwasher, disposal, kitchen counter receptacles)

Test the A/C on that solo 20 amp circuit and see if it works.

If it does, then you may have to run a drop cord to get it placed where you need it.
PaleoWorx
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Re: Portable AC keeps tripping breaker

Post by PaleoWorx »

GaryA505 wrote: Thu Apr 16, 2020 1:58 pm Modern TVs don't use that much juice, so it's just the AC unit.
exactly
TVs use close to nothing. Its the AC that overloads the line. Wither upgrade the electrical panel, or downgrade the AC.
Topic Author
Kennedy
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Re: Portable AC keeps tripping breaker

Post by Kennedy »

The tenant reports that the portable AC is 5-6 years old. Is it possible that the unit can draw more energy that what it's supposed to if it is close to its end of life?
FishTaco
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Re: Portable AC keeps tripping breaker

Post by FishTaco »

HVAC units draw the most power when the compressor starts. You can install a hard-start capacitor that piggybacks upon and increases the charge that the capacitor holds. I've never done it on a window unit, but its super easy on a household unit.

Something like this:

https://www.amazon.com/Supco-SPP6-Hard- ... 313&sr=8-3
inbox788
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Re: Portable AC keeps tripping breaker

Post by inbox788 »

Other than the TV (what kind and how old?), what else is on the same breaker? I'd guess it's more likely that there's unknown loads than a failing AC. You could try a heater or hair dryer to see if that trips the circuit as well.
Glamdring
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Re: Portable AC keeps tripping breaker

Post by Glamdring »

FishTaco wrote: Thu Apr 16, 2020 5:16 pm HVAC units draw the most power when the compressor starts. You can install a hard-start capacitor that piggybacks upon and increases the charge that the capacitor holds. I've never done it on a window unit, but its super easy on a household unit.

Something like this:

https://www.amazon.com/Supco-SPP6-Hard- ... 313&sr=8-3
Good suggestion but for a small a/c unit I have another thought assuming nothing else is running on this circuit. You need a breaker designed for A/C units. I have forgotten the details but it is “slow acting” so it does not trip as easily under the instant compressor starting load. An electrical supply house can tell you what to buy and once you have it in your hand any electricians can swap it out with your existing residential breaker. DO NOT buy a breaker greatly in excess of the load.
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walkabout
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Re: Portable AC keeps tripping breaker

Post by walkabout »

It sounds like the unit is too large for the 15 amp circuit. At startup it could be drawing as much as twice its running draw. It needs to be plugged into a 20 amp circuit, if there is one in the house. Someone upthread recommended using an extension cord. I would not recommend that, even if your tenant were about to get a “good one” (12 gauge wire).

For some perspective on how much HVAC units can draw at startup, the NEC allows (that might not even be a strong enough word) a fixed HVAC units (like a heat pump compressor) to be connected to the service panel with wire rated for their running draw and protected by a breaker that is actually “too large” for the wire. The same concept holds true for a window unit. It will have a relatively large startup draw (inrush), so it needs to be plugged into a circuit sized to handle it. Note that the NEC does NOT allow “regular” circuits to be protected with a “too large” breaker.

If this rental property is in a climate such that it needs air conditioning, but doesn’t have a built unit (or maybe it does but supplemental cooling is still required), you should look into having a proper air conditioner circuit installed. To be on the safe side, it should probably be a dedicated 20 amp circuit run from the service panel to a location near a window and without any additional outlets on the circuit.

Good luck!
Topic Author
Kennedy
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Re: Portable AC keeps tripping breaker

Post by Kennedy »

inbox788 wrote: Thu Apr 16, 2020 5:30 pm Other than the TV (what kind and how old?), what else is on the same breaker? I'd guess it's more likely that there's unknown loads than a failing AC. You could try a heater or hair dryer to see if that trips the circuit as well.
I am told the tv is brand new. It's a regular 4K with an xbox attached. According to the labels in the panel, there are two bedrooms and a bathroom on the same circuit. I was told that the breaker tripped when only the AC and the tv/xbox were in use- no lights or anything else were on.
Topic Author
Kennedy
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Re: Portable AC keeps tripping breaker

Post by Kennedy »

walkabout wrote: Thu Apr 16, 2020 6:44 pm It sounds like the unit is too large for the 15 amp circuit. At startup it could be drawing as much as twice its running draw. It needs to be plugged into a 20 amp circuit, if there is one in the house. Someone upthread recommended using an extension cord. I would not recommend that, even if your tenant were about to get a “good one” (12 gauge wire).

For some perspective on how much HVAC units can draw at startup, the NEC allows (that might not even be a strong enough word) a fixed HVAC units (like a heat pump compressor) to be connected to the service panel with wire rated for their running draw and protected by a breaker that is actually “too large” for the wire. The same concept holds true for a window unit. It will have a relatively large startup draw (inrush), so it needs to be plugged into a circuit sized to handle it. Note that the NEC does NOT allow “regular” circuits to be protected with a “too large” breaker.

If this rental property is in a climate such that it needs air conditioning, but doesn’t have a built unit (or maybe it does but supplemental cooling is still required), you should look into having a proper air conditioner circuit installed. To be on the safe side, it should probably be a dedicated 20 amp circuit run from the service panel to a location near a window and without any additional outlets on the circuit.

Good luck!
Thank you. Good suggestions.
Turbo29
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Re: Portable AC keeps tripping breaker

Post by Turbo29 »

renue74 wrote: Thu Apr 16, 2020 3:31 pm Newer breaker boxes contain Arc Fault breakers, which often have more nuisance trips because of their sensitivity. That may be your issue.
It could be that too. My house has arc fault breakers on the bedroom circuits. If I plug the vacuum into a bedroom receptacle and turn it on it pops the breaker.
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JonnyB
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Re: Portable AC keeps tripping breaker

Post by JonnyB »

Assuming there are no other large loads on the circuit (a TV is not a large load), the 15 amp circuit should be fine. But you may need to replace the breaker because it is faulty.

Breakers have a thermal time delay built into them to handle the start up current of the compressor. For example a typical 15 amp breaker should allow 8 times rated current (120 amps) for 0.5 seconds and 3 times rated current (45 amps) for 10 seconds without tripping.

The delays above should allow plenty of time and current for the compressor to start. So it's possible that your circuit breaker is old and no longer providing the proper trip delay.

Circuit breakers are cheap, less than five bucks, and can be replaced in just a few minutes. The tricky part is that you need a breaker that is physically compatible with your panel box. Some of the older ones can be hard to find. An electrician would know what to look for. Or if you are confident in your abilities, you can pull the breaker and take it to an electrical supply house or box store to find an exact replacement. You need to look at all the tabs and slots on the back of the breaker for exact match.
Point
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Re: Portable AC keeps tripping breaker

Post by Point »

They may need to determine what other outlets are on that breaker as well. Chances are it is not just a single outlet, or even a single room.

Odds are the documentation says to have the unit on a dedicated 15 or 20 amp circuit.
suemarkp
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Re: Portable AC keeps tripping breaker

Post by suemarkp »

If the AC unit requires a 20A circuit, it will have a 20A plug. If it has a 15A plug, it should work, but will need most of it (should work with a TV and some lights). A 10.4A nameplate value should be fine on a 15A circuit. Most residential breakers are marked HACR (Heating and Air Conditioning Rated).

I'd swap the breaker first as it may be bad. If its an Arc fault breaker (should be if its a newer house and this is a bedroom circuit), those are pricy, so I'd try it on another circuit first to make sure the AC unit isn't going bad. Ideally, you'd use a different 15A circuit that has no load on it with a 14 or 12 gauge extension cord. A 20A circuit may hold, but that does you no good if the room you want it doesn't have a 20A circuit. Arc fault breakers can be fussy, and most manufacturers have come out with updated ones (often more than once) so they nuisance trip less than the old ones.

What brand is your circuit breaker panel and what breaker type does it use (e.g. Square D with QO, Square D with Homeline, Cutler Hammer CH, Cutler Hammer BR, GE with THQL, Siemens, Murray, ...the list of possibilities is long).
Mark | Kent, WA
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wander
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Re: Portable AC keeps tripping breaker

Post by wander »

What is the brand and model of the portable AC?
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