Pro-melt furnace tripping GFI plug

[Aldeer]

Got an RCBS Pro-melt furnace last week. It was tripping the GFI plug when I turned it on. After a talk with MidwayUSA they sent out a replacement. The replacement is doing the same thing. Anyone else encounter this?

[slughammer]

Got an RCBS Pro-melt furnace last week. It was tripping the GFI plug when I turned it on. After a talk with MidwayUSA they sent out a replacement. The replacement is doing the same thing. Anyone else encounter this?

Replace the GFI. I had one that would always trip from my electric smoker. Replaced it with a new outlet and the problem went away. Smoker and lead pot are both resistors.

[D.Mack]

ALDEER You don't need to replace any thing, the GFI is doing it's job exactly as it was designrd to do. The Pro- melt is just drawing more power than the GFI was designed for. JUst plug it into a regular outllet. yes it will be safe, the GFI is just a mini-circut breaker for small loads, and pluggging into a regular outlet will put you on the regular house breakers. DM

[454PB]

I'm with Slughammer. I've installed many GFCI outlets, and occassionally you get one that is bad or "overly sensitive". When I wired my shop, every circuit I installed was protected using GFCI outlets. One of them does as you describe, and will trip the instant anything is plugged in. I reset it and go on about my work, but it really needs to be changed. Most of them are rated 15 to 20 amps, and will handle that load unless faulty. If other loads trip that GFCI, it needs replacing. If the Pro-melt trips any other GFCI protected circuit, it has a high resistance short to ground.

[Aldeer]

I tried both Pro-melt units on three different GFI circuits (20 amp) in the house. Both units trip all three circuits.

[helenajoe]

Hi,

I, too, had a tripping GFI problem that was very frustrating. Turns out after much investigation (replacing the GFI didn't help), there was a junction box of wiring that had wire nuts that were NOT the correct size for a snug tight connection.

What was puzzling was that things would work OK but it was hit and miss. Finally found that loose wiring in the junction box (wrong size wire nuts) and fixed that problem and I haven't had a single problem since.

I'm not saying that is your problem but a simple check of your wiring will sure rule it out or not. Strange things happen in life and electricity sure has a life of its own.

Good luck and be safe,
helenajoe

[crazy mark]

A GFCI actually measures current flow from the hot to neutral or ground. If it sees an inbalance it will trip. I have a pot that is 2 wire and it actually has 35-45 volts to ground while it is warming up. Once it gets hot enough the volts to ground is 2-5. We have a meter at work to measure case leakage and ground resistance and it is interesting what case leakage various appliances/medical equipment have when the ground is taken away.
GFCI's will trip if too many amps are ran thru them. Need to remeber they are rated for 80% of labeled amperage. A 20 amp unit should only have 16 amps max ran thru it. 15 amp unit would be 12 amps. Mark

[Dale53]

In my "Florida" room (screened porch with sliding glass windows) I have an overhead fan. The fan is wired up to a GFI. Nearly every time that I shut the fan off, the GFI trips. If the RCBS pot is two wire, you might try grounding the frame of the pot. If the pot is two wire, there might be a "potential difference" - the ground wire would solve that. However, if the pot is three wire (I would guess that it would be) I have no solution other than to either raise the rating of the GFI or just simply install a "normal" outlet. Personally, I would just install a normal outlet and depend on the box breaker for safety.

Dale53

[Edward429451]

So what is the amp draw of the pot? Or wattage. You may need a 25 or 30 amp breaker. Wire size back to the panel has to be considered also.

[versifier]

Just replace your GFI outlet with a conventional one and you too can be a happy caster.
GFI's don't get along with tools very well. I installed hundreds of temopraries with code mandated GFI's and replaced them immediately after inspection to keep the contractors happy. Their main use it to keep you from getting toasted when you run your electric razor while standing in your bathtub, or running a circular saw outside in a monsoon. As long as you aren't casting while showering, you'll be fine. Putting a bigger breaker in is like replacing a fuse with a penny - not a good idea. The actual problem could be as simple as the pot's neutral and ground wires running together inside, which is no big deal.

[slughammer]

I tried both Pro-melt units on three different GFI circuits (20 amp) in the house. Both units trip all three circuits.

If all three of the GFI's are the same mfg, they may be acting the same. I plug my 1000watt Lyman into a GFI and have no problems. I'd be tempted to spend the $13.99 and buy a new GFI with 20 amp and 20 amp feed through.

I'd hate to see an insurance claim denied because of a missing GFI. If the problem continues contact RCBS Tech via e-mail, they are very helpful.

[grumpy one]

Never having heard of a GFI I'm guessing here, but from the problem you're having it sounds as if it may be an earth leakage detector/core balance relay. Such devices trip if there is a certain threshold current in the earth wire - somewhere around 20 milliamps. US wiring code is different from ours, partly because we use 240 Volts instead of 110, so safety practice is much more important here. All of the General Purpose Outlets (wall sockets) in houses that have been wired in the past ten years or so here have to be protected by an earth leakage detector, which is just one device built into the fuse box. If you get earth leakage in any device in the house it trips out every wall outlet in the place, which kind of gets your attention pretty quickly.

There is one kind of device that is very prone to tripping earth leakage detectors: anything with a sheathed-and-insulated electrical heating element. These elements have a nichrome wire running through a steel sheath, with aluminium oxide compressed into the space in between to act as an insulator. The steel sheath is grounded, so any current leakage through the aluminium oxide to ground immediately trips the earth leakage detector. That is the whole purpose of the thing - if the steel sheath is carrying current, it is potentially live and highly dangerous.

I've had to toss out a couple of electric barbeques and at least one electric jug because they started tripping the earth leakage detector. Nothing wrong with them that you could see, and anyone who lived in an old house that didn't have an earth leakage detector could have used them for years and wouldn't have even known about it. They weren't even very old - just potentially unsafe.

It sounds as if your melting pot has earth leakage, and needs to have its element replaced. You can find out for sure, by checking three things. First, is your GFI an earth leakage detector? Second, does the pot have a ground connection? If both answers are yes you don't really need to do the third thing, and it is potentially dangerous, but if you want to go the whole way, temporarily disconnect the earth wire from the pot and check whether it stops tripping your safety switch - CAUTION - DO NOT TOUCH ANY METAL PART OF THE POT WHILE YOU ARE DOING THIS - THE ENTIRE THING MAY BE LIVE. I'M SERIOUS HERE - IT IS VERY DANGEROUS TO PUT POWER ONTO A METAL DEVICE WITHOUT AN EFFECTIVE EARTH CONNECTION. If it stops tripping, you can be 100% certain that you have an earth leak in the pot, and it is dangerous to use. DO NOT leave the earth disconnected - doing that is almost certain to electrocute somebody sooner or later, probably sooner, because the entire metal structure of the pot will be live.

Geoff

[georgeld]

Aldeer: Look at the spec plate on the pot, it should tell what the amp draw is, compare that to the GFI. You may just be drawing more juice than what that very sensitive breaker will carry.
Just because it don't trip with the other pot, don't mean a thing. That one might not draw as much as this one. make sure you've got enough capacity to carry the load it requires to operate. You sure don't want to heat things up in the wrong place and cause a fire.

Grumpy: Over here in the US like you say, we run most things on 110/115/120v, where you guys and Europe run on 220/240v.
Seems like that would be much better as it costs half as much to use too.

Some years back the electrical board in the building trade's "up graded" the building code's. One of the many things they changed was "any new building/electrical outlets must have a GFCI.

All that amounts to is a very sensitive breaker built within a double wall outlet. Any installation within a bathroom, kitchen, or outdoors, porch etc is required to use these type's of outlets. Which really is a good safety device like mentioned above. It's supposed to trip before there's enough amps to injure someone. But, they are a PITA to use with many things such as this heater he's trying to use.

Most of us have gotten bit a few times with tools in damp areas, or when they have a problem, these outlets are supposed to trip/break before you can get hurt.

It's also a greed/profit factor too. Instead of a 39 cent outlet, we've got to pay $3-15 for these things. What's easier? Pay the extra's, or pick your ass up after the jolt knocks you for a loop??

I'd just plug it in somewhere else, or have it checked. "Just because it's new, don't mean it's good!!"

[454PB]

Grumpy one is describing a GFCI, or ground fault circuit interupter. As was previously stated, it monitors milliamps of current in the ground (or earth), when they exceed a certain value, they trip. A ground wire in a 3 wire 120 volt circuit should never have current flow, the neutral should and does. I used to work inside hydroelectric turbines, which are constantly wet, even after being shut down for several days or weeks. More than once my a** was saved by a GFCI while using power tools in this environment. Most power hand tools are double insulated these days, and some don't even have a ground. I will not live in a house without GFCI protection in the bathrooms or around the kitchen sinks. They are an extremely effective insurance policy to protect not only you, but your wife and kids/grandkids.

I believe the RCBS Promelt uses a three wire system and is about 1000 watts, which is only 8.3 amps at 120 volts. Unless there is other load on the circuits you were having trouble with, it is NOT load that is tripping the GFCI. Overloads will generally trip the breaker in the load center, not the GFCI itself.

I own and use three Lee bottom draw pots, all are grounded and feed by GFCI protected circuits, and none have ever tripped.

I'd suggest you do a simple, cheap test. Buy one of those $1 grounding adapters. Plug your pot into the grounding adapter, then plug the grounding adapter into the GFCI circuit. If it no longer trips, you have a bad heating element. When you are done, destroy the grounding adapter to insure it never gets used again, because you have effectively bypassed the GFCI protection.

[hpdrifter]

I am a certified(state of Texas) Electrician. Listen to what 454PB says, he is speaking the accurate truth.

[Aldeer]

Problem appears to be solved. Replaced the GFCI plug with a new one. First time turning the thermostat up it tripped, but after a reset it didn't trip anymore.

Thanks for all the help.

Aldeer

[Lee]

Power is power, whether it be 110 or 220 or 3300 volts. You don't get "half price" power by doubling the voltage. Watts = Watts. Period. And resistive watts ALWAYS equals resistive watts. Period. You are buying the watts, not the volts.
Higher voltage WILL save a FRACTION of a CENT yearly thru lower resistive losses due to lower amperage draws, for the nickel and dime residential consumer, who is using 110/220VAC service. It will save much more when you are transporting large amounts of power over long distances, like the power companies do. Then a higher voltage is an advantage to have.
Any power company charging half price for 220 volt power vs. 110 volt power to a residential consumer has an idiot and an imbecile for a CEO and CFO. And I wanna sign up right now for that discount.

[felix]

Grounding problems have been the plague of the electronics business since day one. It took nine months to find a loop in a packaging machine after being made obvious that a loop was indeed the problem. The problem was found by trial and error, by re-placing various electromagnetic parts, including "computer" boards
and boards having various arrays of power-controlling selonids. ... felix

[hpdrifter]

Lee, I'm glad someone said something about them there watts. I get kinda tickled when someone says that 230 is a lot cheaper than 120. Shoulda said something, but kinda let it slide.

[grumpy one]

Problem appears to be solved. Replaced the GFCI plug with a new one. First time turning the thermostat up it tripped, but after a reset it didn't trip anymore.

Thanks for all the help.

Aldeer

It's much more likely that the current leakage to ground is either intermittent, or right at a threshold level for tripping your GFCI. I've personally never heard of a section of powder-insulated heating element curing itself of a leakage fault. However if it is RCBS your replacement heating element should be free when you get to that point and make a warranty claim.