Ground fault caused by element dry-firing?

[mwill07]

So i screwed up a cleaning session yesterday - inadvertantly left the discharge from my pump outside the kettle while running and heating, and walked away to make a sandwich. I came back and my rig had now power and no water... the GFCI/breaker had thrown. No beer was harmed - it was just cleaning water.

A visual inspection inside the control box, all cables, and the element showed no visible damage. I was able to isolate the fault to the heating element - i can power up everything no problem if the element is unplugged, but if its plugged in, GFCI/ breaker shuts it down immediately when i switch the element on.

I took an ohm meter across the element. I measured 10.3 ohms across the element terminals (unplugged, of course). Each leg to ground: there was resistance, increasing with time, in the Kohm to Mohm range.

I think its a GFCI fault in the element, caused by dry-firing. Does this make sense? Common issue? Happen to anyone before?

 

[Vale71]

You fried the internal insulation and the resistive wire has formed a circuit with the (grounded) meatal casing causing the GFCI to (thankfully!) trip. I'm afraid replacing the element is your only option.

 

[mwill07]

You fried the internal insulation and the resistive wire has formed a circuit with the (grounded) meatal casing causing the GFCI to (thankfully!) trip. I'm afraid replacing the element is your only option.

Thank you. This is my assumption as well, but I'm not familiar with internal construction of heating elements and I can't seem to find a whole lot of examples of this particular failure mode.

Curious if anyone else has experienced this?

And yes, very thankful for the GFCI. Glad I had that in place.

 

[Dland]

Can you take cover off element where it plugs in? I had one that melted some of its insulation because one element leg was not tightened enough during factory assembly. The element still works, but since housing insulation is damaged, I am using another one. It could be used in a pinch, but I had a spare. You could take apart and see if arc condition can be corrected.

 

[passedpawn]

Just replace the element. Cheap fix, seems that all evidence points there.

 

[mwill07]

Can you take cover off element where it plugs in? I had one that melted some of its insulation because one element leg was not tightened enough during factory assembly. The element still works, but since housing insulation is damaged, I am using another one. It could be used in a pinch, but I had a spare. You could take apart and see if arc condition can be corrected.

I did. I could see no evidence of arc, everything was tight, no melted insulation, etc.

I'd be very cautious of using something with melted insulation. At the very least, I'd add whatever extra insulation i could. Heat shrink would probably be the best bet.

 

[Dland]

Don't worry, I would not use in present condition, always keep a couple of spares. The actual element in my case has no damage, so if one fails in a different way, I could put the two together.

 

[mwill07]

Just to close this out: I ordered a new element. After installation, i fired it up and all is well. For future reference, on the new element i still measured 10.3 ohm between the hot and neutral legs, and infinity to ground.

 

[doug293cz]

Just to close this out: I ordered a new element. After installation, i fired it up and all is well. For future reference, on the new element i still measured 10.3 ohm between the hot and neutral legs, and infinity to ground.

That's what the elements are supposed to measure. If you don't have infinity to ground, you will trip the GFCI.

Brew on