Dryer trips 30A GFCI breaker


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Old 12-29-21, 09:22 AM
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Dryer trips 30A GFCI breaker

Hi all, I live in a townhome in Northern Virginia built in the mid 80's.

I currently have a 30A double pole breaker feeding 220v to my laundry room through a 10-30 outlet (current wiring is shown in the pic below). In this outlet I have two hots and a neutral attached to the receptacle, and a ground coiled up (unused) in the back of the outlet. In the panel the two hots go to the breaker, and both the neutral and ground connect to their respective bars. 90% of the time I run a dryer off this circuit - the other 10% of the time I run an electric brewery (requires 15A) off this circuit. For safety, I added an in-line 20A GFCI between the brewery and the outlet - this has been working great for over a year.

Flash forward to now - I just recently upgraded my brewery to a new 30A system - so the previous in-line GFCI will no longer work. To rectify this, I purchased a Homeline 30A double pole GFCI breaker with the intent to swap the breakers in the panel. I swapped the breaker and wired it per the directions like Option A in the picture below. All is good when I flip the breaker on, but as soon as I plug in my dryer, it instantly trips. If I reset the breaker and plug in my old 15A brewery from above it works just fine. I'm looking for confirmation, but my assumption is that because of the way a 3-wire dryer is wired, with the washer neutral connected to ground, this is causing a ground fault the second I plug the dryer in. I'm not aware of a safe way to rectify this and make it work with the current receptacle.

Which leads me to Option B in the drawing below - which is what I think everyone will recommend. My thought is that because I have an unused ground sitting in the back of my outlet, that I should just convert my receptacle and plugs to 14-30's, then just re-wire the dryer to be 4-wire compatible. Is my assumption correct here? Will this allow the GFCI to function correctly?

I know there are also configurations where I can keep my original 30A breaker and just add a GFCI spa panel that I plug in to the laundry room receptacle when I need it, but for the sake of space and a cleaner install, I'd like to get the panel GFCI working, if possible.

Thanks for any, and all advice.


 
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Old 12-29-21, 02:57 PM
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You have to use option B. When using 3 prong plug, neutral wire is bonded to ground. This is considered ground fault condition to GFCI breaker.
3 prong receptacle should not have been installed in the first place when you already have 10-3 cable run to it.
 
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Old 12-30-21, 07:25 AM
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The receptacle and cord needs to be changed to a 4 wire setup. The bond strap in the dryer will also need to be removed.
 
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Old 01-03-22, 08:09 AM
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Thank you both for your input, it's much appreciated.

Admittedly, I was very surprised when I pulled the receptacle cover off and saw the unused ground coiled in the back. Since the house was built in the mid 80's I had assume there would only be HHN - and back then 3 wire was still to code.

Anyway, I'm beyond pumped that I have 4 wires available and will convert everything to be up to code. Again, thanks for confirming my assumptions.

Cheers!
 
 

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