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. :-D
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.

[D.Mack]

Yes grounging problems can be fun. Last year my neighbor had a cable install update. AS we watched the installer explained he had to ground to the metal valve on the cold water pipe, he insisted it was necessary, and required by code. The only problem was the metal fixture, was attached to pvc pipe where it went into the ground. We waited till he left then ran 5 feet of wire to the houses grounding rod. DM

[D.Mack]

HPDRIFTER, or CRAZY MARK, (or any one else who knows more about electricity than me). What would be the results in this case if the polarity of the wires were crossed on the GFI? I know this would be a potentialy hazardous situation, but may not be apparent at first. DM

[crazy mark]

The GFIC shouldn't work. In other words you couldn't hit the reset button and get it to stay on. I recently had that problem on an older house. the hot and neutral had been reversed in the outlet in the front room that fed the GFIC outlet on the front porch. Once I straightened that out all was fine. All outlets are color coded. Brass color terminal is the hot or ungrounded wire, silver is the white or grounded wire and green is the grounding wire. Back at your panel box the white and ground wires are actually connected by being bonded to the electrical box. They do serve different purposes however. The neutral carries the unbalanced load and the ground provides a path for a short to ground so you don't get shocked when you touch something metal that has a "hot" case. Mark Oregon licensed LME and LEA electrician.

[versifier]

Yes grounging problems can be fun. Last year my neighbor had a cable install update. AS we watched the installer explained he had to ground to the metal valve on the cold water pipe, he insisted it was necessary, and required by code. The only problem was the metal fixture, was attached to pvc pipe where it went into the ground. We waited till he left then ran 5 feet of wire to the houses grounding rod. DM

Depending on the pH of the water and what happens to be dissolved in it, grounding to the water line can cause the electrolytic deposit of minerals on the inside of the copper pipe, sometines very quickly. I have seen similar grounding efforts by the telephone company clog up a 1/2" pipe in a month's time. The ground is required by code, not the hooking up of the ground wire to the water pipe - that's just laziness in my opinion. Btw, just the water in the line was enough to properly ground a low voltage setup like the cable line even if it ran in pvc for a stretch (most older municipal lines are cast iron), but that doesn't mean it wasn't a smart idea to hook it up to a real ground instead, it was.

[Dale53]

Versifier,
You are certainly correct on the telephone line ground connected to a water pipe causing electrolysis on copper pipe. I had pipe start to leak. When I took the bad section out, I examined it closely and could readily see the electrolysis damage. I called the pnone company, they tried to give me a "ration of s**t". I calmly explained the problem in terms they could understand. They installed a proper ground rod that day!! That has been nearly twenty years ago and I have had NO problems since.

Dissimilar metals will cause the same problem (galvanized tees with copper pipe, for example).

Dale53

[mazo kid]

A couple of years ago, I purchased a used ProMelt pot off ebay. I didn't use it for a few weeks, but when I plugged it in and warmed it up, it tripped the GFCI. Moved it to another circuit and same thing. Long story short, when it returned from RCBS rebuild, it was still doing the same thing. Moved it to a regular outlet and it works fine; put my meter on the metal housing and ground and no leakage there.I am a retired electrician and I agree with someone earlier that said tools and GFCIs sometimes don't get along, depending on type of tool. We used to have a lot of "nuisance tripping" when GFCIs were used in garages with electric openers. Emery

[454PB]

While I was still working, we had to test all our power tools and extension cords yearly. The tester was basically a very sensitive GFCI. We had probably 200 items to test each round, and there was always several that failed the test. If it was an extension cord or drop light, it was more cost effective to replace it, but the more costly tools sometimes took many hours to track down the trouble and repair it. Sometimes it was a simple as using compressed air to blow carbon dust out of the armature. We had a very old but well made and expensive to replace bench grinder that took me several days to fix. Bull headed I guess, but I finally got it to pass by insulating every single bolt hole where the grinder was secured to the stand. This repair was really a bandaid, but hey, it passed the test!

I'm convinced that other than a faulty GFCI (which is fairly common), given enough time and effort, hot to ground leakage can be found and remedied.

[grumpy one]

I'm convinced that other than a faulty GFCI (which is fairly common), given enough time and effort, hot to ground leakage can be found and remedied.

It may not be worth doing though. I had a three-phase motor get immersed in water a year or so back, and it developed earth leakage through the windings after drying out. Maybe if I'd flushed it with clean water enough times it might have cleared up, but it was an old open-frame motor that wasn't exactly state of the art, and I'd never have trusted it again. I tossed the motor, and went to quite a bit of trouble to fit a modern one to the big pedestal grinder it was driving. (It happened that the cheapest nice aluminium-cased sealed motor I found was for an odd speed, so there was pulley work involved as well as motor mounting.) Now that it's done, I'm happy with my choice.