I'm looking to replace the plug on a window air conditioner unit that uses a 6-20 240v plug. However, in addition to the cord having two hots and ground, there's a small blue cable that I'm not sure what it's hooked up for. Is it for the circuit breaker (leakage current sensor, or LCDI; it's similar to a GFCI receptacle with the test & reset buttons but apparently for a different use) built into the plug, and if so can I bypass it? And if not, what is it for, and how do I account for it on the new plug, which just takes hot, neutral, and ground? I realize the risks of just bypassing it, but I'm desperate.

The air conditioner probably around 15 years old, give or take. At least 13 years. It's a Whirlpool, the model is ACQ244XR2.

The longer story, I'm hoping this will fix the air conditioner. It simply does not turn on anymore; there's no display, and the controls don't work (it's all digital). The test/reset breaker on the plug actually still seems to work okay, but of course, there's no power. I've tested the plug with a multimeter and everything tests okay (there's the occasional jump to 1000 when I wiggle the lead connected to a hot but I'm assuming that's user error or from it being a cheap multimeter). All in all, I can't afford to replace it or hire an electrician so I'm hoping this is the only issue. Any help at all would be greatly appreciated.

  • 1
    A 6-20 doesn't have a neutral. Just two hots and a ground. As a practical limitation of using commonly available cordage, one of the hots may be white. The hots are interchangeable. Sep 27, 2018 at 19:50
  • A GFCi is exactly what that thing-on-the-cord-is. Plugging one into a GFCI protected socket would be just as good. Trouble for you is, it's a 240V GFCI, and those are rarer than black swans in the "GFCI+receptacle" formfactor. They're available as breakers, for $80. One more thing, what is the SEER number of this unit, and how often do you plan to use it? Sep 27, 2018 at 22:32
  • I always do that about hot and neutral, should know better by now. I have no know what the SEER number is for it, it's been so long since we bought it and I don't see where it's printed on it; I do recall that it was supposed to be pretty efficient, but it was still a mid-range or so air conditioner. The air conditioner is used fairly heavily - it's the one for the main room of the house, den & kitchen. Sep 28, 2018 at 22:28
  • Did you ever get this resolved? If so, please give a check-mark to the answer or write up your own answer explaining what you did to get it fixed and give yourself a check mark. That will help others with this kind of problem know that this has a resolution and is a good place to look for their answer.
    – FreeMan
    Aug 6, 2020 at 21:01

1 Answer 1


That blue wire is likely testing the integrity of the ground and if not connected correctly, will not allow it to work. ACs like this create static electricity and that needs to go safely to ground. The 240V will work fine without it, so that blue wire is making sure that you have a good ground connection before it allows it to run.

Along those lines, when you say you tested it with a multimeter, what did you test? The fact that you seemed to think there was a "neutral" on a 240V circuit kind of indicates you don't know what to look for. You need to have 120V from either hot pin to ground, and 240V from hot to hot. There is no neutral. So if you measured no difference from one of the hots to ground, thinking that was neutral, that's your problem. One of your hot's is open. That would explain why your AC is not working.

  • I tested from one hot pin to the other, and from the hot pins to the ground one at a time. For some reason a long time ago, I got it stuck in my head about one pin being hot and one being neutral so that's how I end up saying it, but I did the test right. So, is there something I can do with that blue wire so it doesn't cause a problem with a new plug? Connect it to the ground pin along with the ground wire, just to be safe? Thanks. Sep 29, 2018 at 23:40

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