Anyone wants to take a shot.
I seen this posted somewhere else, and was amazed by the answers I seen. Yet would love to see what you get.

The unit is a Residential room Window Air Conditioner--with cord and plug. (Cord and Plug has a trip button)
Nameplate:
Volatge 230/208
Watts 1850/1800
Amps 8.3/9.0

Heating:
Watts 3,670/3100
AMPS 16/15

Question:
-What size conductor can I run from the panel to a 240V receptacle
-What size breaker do I need

OOH,OOH OOH,I know I Know...

I will be interested in seeing the answers also. I would like to also know how this is calculated, why, what code section this falls under.

For clarity I assume this is a combination unit with heat and AC built all into one appliance.

I love riddles.

Bet you thought I was going to answer. Ha, fooled you.

Remember everyone, there is a link in the Read First sticky note at the beginning of the electrical forum to the NEC with instructions of how to get there.

Washington, I would be interested in seeing the other answers you found or received. Even some of the best electricians I have met have problems understanding HVAC.

By the way, the run is 40 feet from the panel!

TK,
I will post one of the answers!

Thanks!

At the risk of getting ridiculed 12 Ga, 20A; So the cord has a GFCI - So?
Assumption: Both can't run at the same tme

Well I see you received only one answer, which happens to be correct.

I did not get any reason or code section.

The assumption is correct, that is why I was hoping for the code section.

AC units have been coming with Arc Fault protection built into the power supply cords.

Washington, do you agree with the #12 wire and 20 amp CB?

Ok, I didn't want to give it away. A/C may have mislead someone. It was a combo unit and I assumed that both would not be on at the same time, so the highest load prevailed. I didn't bother normalizing the load to 240 V. We know by experience that 12 GA is good for 20 A (An ampacity table verifies), but but just to use the 40' or really 80', looked at the voltage drop in the leads. It didn't appear excessive. Chose the next standard breaker of 20A.

Quote:

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Originally Posted by tkrussell

Well I see you received only one answer, which happens to be correct.

I did not get any reason or code section.

The assumption is correct, that is why I was hoping for the code section.

AC units have been coming with Arc Fault protection built into the power supply cords.

Washington, do you agree with the #12 wire and 20 amp CB?

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Sorry, been busy trying to find work for my company. Things have slowed down greatly!

Yeah, I agree. Heck the answer was in the pudding. Personally, I still would have ran #10, but that's me.

I look @ 440.32/440.62 (A)/ and 210.23(A) and (B) depending. Or just look at the cords rating :)

Correct regarding 440.62, as the unit is a room air conditioner, and does fall under Article 440 VII, Section 440.60.

Section 440.32 does not apply.

#12 is the minimum size allowed, exceeding the code is always a good practice.

Depending on the length I may install #10, but for most normal runs, say 50 feet and under, I would sleep fine with #12, and pass the cost savings of copper, such as it is today, onto the customer.

The trip button is the Arc Fault required to be factory installed as per Section 440.65.

If this was a permanently installed heating/air conditioning unit, none of these sections would apply.

Quote:

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Originally Posted by tkrussell

Correct regarding 440.62, as the unit is a room air conditioner, and does fall under Article 440 VII, Section 440.60.

Section 440.32 does not apply.

#12 is the minimum size allowed, exceeding the code is always a good practice.

Depending on the length I may install #10, but for most normal runs, say 50 feet and under, I would sleep fine with #12, and pass the cost savings of copper, such as it is today, onto the customer.

The trip button is the Arc Fault required to be factory installed as per Section 440.65.

If this was a permanently installed heating/air conditioning unit, none of these sections would apply.

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Exactly! Note that I said I look at! :)

There's always some considerations, if the window A/C doesn't meet the requirements.

I agree TK!