GFI Outlet Tripping

[SoundGuySays]

Looking for any insight on my situation:

I have an A/C unit that is supposed to be 15A, 1240W, 115V. Since all of the bedroom and living room outlets in my apartment are all on the same 15A breaker, I decided to run a heavy duty extension cord to plug this A/C unit into one of the few outlets that is on its own breaker. This outlet is in the kitchen and the breaker is rated at 20A. The extension cord is a 10-gauge, 30A, 50-foot cord.

After the A/C unit runs for about thirty seconds, the GFI on the outlet trips and the unit shuts off. I did some research before purchasing the extension cord and felt confident that it was a high enough gauge to not cause an electrical hazard; I also figured the 20A breaker would be sufficient since the A/C unit rated at 15A. However, I never considered the GFI on the outlet. Is the outlet possibly faulty or 'extra sensitive', thus the break after I turn the unit on?

Any help would be much appreciated!

 

[Dartlec]

Hopefully @Megawatt can advise as it's a US specific issue. Or you may get more specific answers in the US part of the forum.

But it doesn't sound like the issue is overload or the extension cord. Some appliances have a high 'inrush' current that can trip a breaker, though again this doesn't seem to be the case here.

I believe the GFI outlets you have there are more sensitive than we have, so it's likely an issue with the A/C 'leaking' too much current onto the earth, or the outlet being too sensitive.

Are all your outlets GFI, or just the ones in the kitchen?

 

[SoundGuySays]

Hopefully @Megawatt can advise as it's a US specific issue. Or you may get more specific answers in the US part of the forum.

But it doesn't sound like the issue is overload or the extension cord. Some appliances have a high 'inrush' current that can trip a breaker, though again this doesn't seem to be the case here.

I believe the GFI outlets you have there are more sensitive than we have, so it's likely an issue with the A/C 'leaking' too much current onto the earth, or the outlet being too sensitive.

Are all your outlets GFI, or just the ones in the kitchen?

I tried testing it temporarily with a #16 extension cord and that worked without tripping the GFI; I was able to run the A/C for several minutes. Perhaps the #10 I'm trying to use is too 'big' and causing the GFI to erroneously detect a leakage?

Only the outlets near the sinks (two in the kitchen, one in the bathroom) are GFI. They were updated to be be on their own, independent 20A breakers. Everything else in the house is non-GFI. The catch is that if I plug the A/C into one of the non-GFI outlets, I can't run my washing machine or vacuum while the A/C is running, hence my attempt to use an extension cord so it could be on an independent breaker.

 

[SoundGuySays]

I tried testing it temporarily with a #16 extension cord and that worked without tripping the GFI; I was able to run the A/C for several minutes. Perhaps the #10 I'm trying to use is too 'big' and causing the GFI to erroneously detect a leakage?

Only the outlets near the sinks (two in the kitchen, one in the bathroom) are GFI. They were updated to be be on their own, independent 20A breakers. Everything else in the house is non-GFI. The catch is that if I plug the A/C into one of the non-GFI outlets, I can't run my washing machine or vacuum while the A/C is running, hence my attempt to use an extension cord so it could be on an independent breaker.

Amendment to my above reply

When I tried the #16 cord this morning, I neglected to lower the temperature setting on the A/C unit. Since the temperature in my apartment had dropped since yesterday, this allowed the A/C to run while it was on the #16 cord without tripping the GFCI. I tried both the #16 and the #10 again today, with the A/C on the lowest possible temperature setting, and the GFCI tripped for both cords.

 

[Megawatt]

Amendment to my above reply

When I tried the #16 cord this morning, I neglected to lower the temperature setting on the A/C unit. Since the temperature in my apartment had dropped since yesterday, this allowed the A/C to run while it was on the #16 cord without tripping the GFCI. I tried both the #16 and the #10 again today, with the A/C on the lowest possible temperature setting, and the GFCI tripped for both cords.

My friend your AC needs it’s own dedicated circuit, not just a general use receptacle

 

[SoundGuySays]

My friend your AC needs it’s own dedicated circuit, not just a general use receptacle

That does indeed seem to be the conclusion! The outlet I'm trying to use is dedicated, but since it has a GFCI, it's not 'communicating' properly with the A/C. I've learned since my original post that a lot of newer A/Cs, refrigerators, washing machines, etc. don't often work well with GFCI outlets.

Thanks for the help!