Power is out with 100+ temperatures. The window AC has a 615r plug and I cannot find an adapter that will allow me to plug the AC to the generator. How do I plug it in?

  • 1
    What model generator do you have, and is it 120V only or 120/240V? Aug 8, 2015 at 23:22
  • 1
    We are going to need the model of generator, or at least what kind of receptacles it has.
    – Grant
    Aug 9, 2015 at 1:29

2 Answers 2


Most portable generators have a few different types of receptacles built in. Most portable generators offer all, or some combination of the following receptacles.

  • NEMA 5-15 (125 volt, 15 ampere)
  • NEMA 5-20 (125 volt, 20 ampere)
  • NEMA L14-30 (250 volt, 30 ampere)
  • NEMA 14-50 (250 volt, 50 ampere)

If you're looking to plug in a device with a NEMA 6-15 plug (250 volt, 15 ampere), you're likely going to need more than a straight wire adapter. You'll either need a small panel with a 250 volt 15 ampere circuit breaker, or an inline 250 volt 15 ampere breaker.

The A/C unit's cord is only rated for 15 amperes. If you made an adapter to go from NEMA 6-15 to NEMA L14-30, for example. The cord could potentially be exposed to 30 amperes, which could cause it to fail catastrophically.

You need is a circuit breaker between the 30 ampere receptacle, and the 15 ampere plug. The circuit breaker will protect the A/C unit, and the cord.


In the United States, a NEMA 6-15R receptacle is typically used on Air Conditioners that require 240 Volt AC service (sometimes called "220".) See this diagram at this Wikipedia article.

If you have a generator with a 120 Volt AC output (sometimes called "110"), do not attempt to connect a 240-Volt air conditioner, not even using a plug adaptor. This could be dangerous, or damage your equipment.

If your generator has a switch to allow you to select "120 or 240" Volts -- and again, it could be marked "110 or 220" -- then it should be safe to:

  • select 220-240 Volts
  • make sure your Air Conditioner is rated for 220-240 Volts
  • connect the Air Conditioner to the generator, even if an adaptor is required.

You may be able to get an adaptor at your local hardware store/electrical supply/home improvement center, or wire one together from individual parts they can sell you. If you have any doubts, talk to a qualified electrician.

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