Help with Dryer Tripping Breaker

[Robert Coats]

Bought a used LG dryer (electric) and tried it for the first time today. As soon as I plugged in the big 4-prong plug, the twin 30A GFCI breaker trips. Tried a reset, and it instantly trips again. Will only reset if plug removed from dryer 220V outlet.

Dryer had a 3-prong plug when I bought it, and updated to a 4-prong, as that is what we have in the laundry room. Verified the black, white, red and green leads were all correctly attached to the dryer, as well as confirmed each had continuity from the ring connector to prong.

Also correctly measured 120V at each side of the outlet. I am sure the outlet, wires, breaker, etc. are all working and installed correctly.

From what I've read online so far, the dryer may have a failed heating coil, which could ground out. Significant effort required to disassemble the dryer for access to the coil, so what easier things might I check?

I've read some dryers don't like GFCI breakers/circuit, so for testing purposes, I'm tempted to replace that breaker with a non-GFCI style to see if that solves it. Again, a bit easier than exploratory surgery on the dryer.

Thanks in advance for the help.

FYI, I think code requires all 240V circuits to use GFCI breakers, as we had a totally new panel installed after our fire last year.

[Bob Kontak]

Originally Posted by Robert Coats

I'm tempted to replace that breaker with a non-GFCI style to see if that solves it.

Hold off on that and explain the three prong and four prong business.

Who installed the four prong?

Bet there is incorrect wiring in something in the 220 line.

Take pics and provide types of plugs if you can. Someone here knows way better than me.

[greglepore]

You did remove the neutral from the ground lug in the drier and move it to the neutral on the cord (attached to center lug in dryer)?
https://academy.fredsappliance.com/dryer-training/how-to-install-3-and-4-wire-240-volt-dryer-cords/

[Robert Coats]

Fixed!

After triple checking all the external wiring, breaker, cords, etc., I was sure it was all correct, so took the top off the dryer to have a look inside, and volia! The neutral bonding jumper was disconnected, BUT, its loose metal ring connector was wedged against the dryer's frame. That's why I was getting a short between chassis ground and the white neutral lead (thus causing the breaker to instantly trip). Taped and zip-tied the literal loose end, and she starts and runs great. I think I'll name her Sparky.

[Bob Kontak]

That's a monkey off your back.

Good job!

[masraum]

Originally Posted by Robert Coats

Fixed!

After triple checking all the external wiring, breaker, cords, etc., I was sure it was all correct, so took the top off the dryer to have a look inside, and volia! The neutral bonding jumper was disconnected, BUT, its loose metal ring connector was wedged against the dryer's frame. That's why I was getting a short between chassis ground and the white neutral lead (thus causing the breaker to instantly trip). Taped and zip-tied the literal loose end, and she starts and runs great. I think I'll name her Sparky.

Nice!

[sc_rufctr]

Excellent outcome. I don't envy you guys. In Australia all of our outlets are 240v.

Years ago I had a similar issue with my dryer. It took it apart and found an underwire from a bra wedged into the drum support track.
It was causing extra friction as the drum rotated so after a short run time the breaker would trip.

[zakthor]

Bear with me oh knowledgeable ones. I sort of understand the electrics but maybe missing details for happy confidence. My dryer safety ignorance has always bothered me.

I’d like to understand why Americans were not dying in droves for the 70 years that we owned 3 prong 220 dryers…

3 prong dryers run with two blacks and a neutral that was bonded to chassis, so a combined neutral/ ground. The two blacks are 180 out of phase meaning there’s no output to neutral?

To convert 3 prong to 4 you must disconnect all places where white touches chassis, then connect 4 prong ground to chassis. Right? Are there cases where this ‘conversion’ is non trivial? Is such a conversion from 3 prong actually necessary?

What would be wrong with ignoring 4 prong ground and wiring 3 prong dryer as is (using white as chassis ground.)

What is the case where this makes people sad?

Thanks!