Magma Masterpot Woes

[Guardian]

Guys, I need some help troubleshooting a Magma Masterpot. The pot is tripping a GFCI outlet as soon as it is plugged in. It's just the outlet, not the breaker. It is not amperage related, as I've verified a 20 amp furnace still works on that outlet. The Masterpot was used previously on this same outlet without issue.

An Ohm meter indicates some bleed over from either of the hot prongs on the male plug and the ground prong. The Ohm meter is set on 200k and I'm seeing 47 gradually increasing to 150 or so.

I've verified there are no nicks in the wires. I've narrowed it down to the heating band. Is it normal for these to bleed power?

I put a GFCI outlet in for a reason, so I'd prefer not to bypass the safety feature.

I can call Magma Monday, but was hoping to do some casting this weekend.

[Regnar]

I think GCFIs don't like heating elements much. Mr. Google may be more helpful.

[kayak1]

It's in the start of the book. The moisture can create enough of a circuit to trip the GFI. Once you cook the moisture out of it the GFI's not an issues. The issue is the band heater. As I run all my lead to reflux it though my Lee 20lb again before I trust it in my magma I can leave my magma empty and toss a few hot 400F blocks of lead in and they will get rid of the moisture and prevent the GFI from tripping. You can make a custom plug that doesn't connect the ground (might not be legal do at your own risk) and that will stop the issue too.

[Guardian]

Not sure what book you're referring to, but the there's nothing regarding GFCI outlets in the 4 pages that came with the Masterpot. I just went to look to confirm I hadn't overlooked it. There's 2 pages of exploded diagrams; one covering fluxing, ventilation, and thermostat adjustment; and one about installing their PID controller.

I ended up just replacing one of the two GFCI outlets with a regular 20 amp and all is well. The stuff that needed the GFCI still has it.

[kayak1]

It's the same pot as the master caster, this is the master caster manual:
http://www.magmaengineering.com/PDF/Master_CASTER_Instructions.pdf

This is the section I was referring to:
"Ground Fault Interrupter (GFI) circuit breakers can be a problem with the MASTER CASTER pot. Try not
to operate the pot on a GFI circuit. The large band heater tends to absorb moisture when cooling; this
causes the GFI breaker to become sensitive. For example, if you were to plug the pot into a non-GFI circuit
for even a few minutes, then plug into a GFI circuit, the pot would then melt normally. This is not a safety
problem it is just the nature of large band heaters."

[Guardian]

Thanks for that. They don't include any of that language with the Masterpot itself. Strange.

I appreciate the input and I'm on the right track now.

[finishman2000]

I have the same problem. I just plug it into a non gfi outlet for 5 minutes then move it outside and plug into the gci and all is well.

[birddog]

Good to hear as I have a new master pot coming w/pid controller. But have no GFCI's to worry about in the shed either.
Charlie

[Tazza]

Another option if anyone must use something that leaks, on a GFI circuit is to use an isolation transformer. It safely disconnects the earth from the device you are using. If moisture is the issue, run it off the isolation transformer to evaporate the moisture, then plug it in as normal.

Removing the earth is one way, but i'd never recommend it to anyone, i'd rather not get sued. I have done it myself in a time of need before i got to do a proper repair, not safe but it did the job.

[Beau Cassidy]

When my master pot does that I just suck it up and put in another thermostat. Problem solved and an easy fix. When it comes to electtical issues I don't screw around.

[jmay2174]

GFCI (ground fault circuit interrupter) are great devices for protecting against shorts in a circuit that cause electric shocks when the device is touched while you are grounded. It detects any difference between the current in and out of the device and quickly shuts off the current.

The alternative is to use a non GFCI circuit with a three prong plug and cord. The third wire (green or bare copper) is connected to the device metal frame or cover and the wall duplex plug has the third terminal grounded. With this set up, any power short or bleed will go directly to ground eliminating a shock hazard.