Mini-Split Wiring Ghost

[mnwebb]

Hey all,

I had a 12,000 Fuji Mini-split installed and to save $500 I decided to run the power. I'm fairly experienced with the basics of electrical systems, theories and practices but can't wrap my head around this problem.

It's 240v, 20 amp.

I ran about 10 feet of 12/3 Romax and didn't connect the neutral as it's not used.
That runs to a outside cut off box (rated for 30amps) with more #12 wire directly to the unit.

Connected it to a double pole 20amp GFCI breaker and fired it up. A/c seemed to work fine (although it was only 45 degrees at the time) and when I switched the unit to heat the breaker popped. I replaced the GFCI with a normal breaker and everything was fine and worked as it should. Tried a 2nd GFCI and it lasted a little longer than the first but them also tripped. WTF?

Suggestions?

Thanks!
-Wilson

 

[sberry]

Probably a little fault in a control,,, this doesn't need gfci.

 

[mnwebb]

sberry...can you explain what you mean? The installer said it does require a GFCI. Don't most electrical items that are in the elements need GFCI's?

Thanks!

 

[sberry]

I have never seen a gfci on one but havnt been everywhere either. About the onlyist thing I can think of needs gfci is hot tub/pool. Most use for it is for outlets where end users plug stuff in to them. This is a piece of wired and grounded equipment. Not saying it might not have a fault but off hand don't see why it would be required.
someone will be along who has more mileage on them than I do.

 

[jhrodd]

Mine don't have GFCI breakers. Installed by a very experienced electrician and State inspected.

 

[PoorOwner]

I have heard of this happening on GFCI breakers. My house's main AC isn't on GFCI breakers either, why would a mini split need one?

 

[mnwebb]

Good to know PoorOwner and jhrodd sberry thx! I'll ask the inspector next week.

-W

 

[mnwebb]

FYI..." know this is an old discussion but the GFCI breaker IS NOT required and a letter confirming this can be obtained from the manufacturer of the minisplit (in this case Daikin). The breaker will absolutely trip upon startup. It isn't due to current draw but how the inverters work. A GFCI breaker rated for high harmonics (super-expensive) could be used. The reason it still exists in manuals is leftover from overseas manuals as they use different electrical system setups. know this is an old discussion but the GFCI breaker IS NOT required and a letter confirming this can be obtained from the manufacturer of the minisplit (in this case Daikin). The breaker will absolutely trip upon startup. It isn't due to current draw but how the inverters work. A GFCI breaker rated for high harmonics (super-expensive) could be used. The reason it still exists in manuals is leftover from overseas manuals as they use different electrical system setups."

 

[wyliesdiesels]

sberry...can you explain what you mean? The installer said it does require a GFCI. Don't most electrical items that are in the elements need GFCI's?

Thanks!

The installer obviously doesnt know his code.

There is no requirement for GFCI on 240v equipment such as ACs.

And not sure how you came up with the last sentence.

 

[wyliesdiesels]

FYI..." know this is an old discussion but the GFCI breaker IS NOT required and a letter confirming this can be obtained from the manufacturer of the minisplit (in this case Daikin). The breaker will absolutely trip upon startup. It isn't due to current draw but how the inverters work. A GFCI breaker rated for high harmonics (super-expensive) could be used. The reason it still exists in manuals is leftover from overseas manuals as they use different electrical system setups. know this is an old discussion but the GFCI breaker IS NOT required and a letter confirming this can be obtained from the manufacturer of the minisplit (in this case Daikin). The breaker will absolutely trip upon startup. It isn't due to current draw but how the inverters work. A GFCI breaker rated for high harmonics (super-expensive) could be used. The reason it still exists in manuals is leftover from overseas manuals as they use different electrical system setups."

An old discussion that you just posted about this morning?

What am i missing here?