Basic Electrical help,please?

[GT27]

Are there any electricians here that can possibly help me out with a pond pump problem? I have a 800 gallon pond and a 600-800 GPH pump.I plug it into the outlet on my garage that is separate from my house,has the old style 2 glass fuses in it. Line supplied from the house to the garage as a feed.Every time I plug it in it "kicks the GFCI"! I suspected a bad GFCI and replaced it! Same thing!!!! I plug it into the outlet that the garage door is on and it works fine????? Nothing else being used on the other circuit! I have basic knowledge of electrical: meaning bulbs,outlets,and ceiling fans if that helps you realize that I don't have a lot of electrical "edumakation" Anybody have any idea's? Thanks for any input,in advance! GT27

[smoked turkey]

From my experience I think the GFCI is probably ok. It is kicking the breaker in the GFCI due to leakage current which can be from a cord that is either excessively long or a cord that is old and perhaps the insulation is cracked in places along its length. The GFCI is very sensitive to the leakage current between line and neutral. It probably thinks there is a short circuit when in reality it is leakage current. Since you are probably in the water with the equipment you really want a good cord to avoid injury. It doesn't take much current in those conditions to kill a person.

[crazy mark]

A lot of electrical items will trip GFCI's. Air compressors, refrigeration compressors, pumps, and electrical heaters. I can't think of any of these items at work that are hooked up to GFCI's. This is at a hospital. Usually in todays world if something needs a GFCI it is already attached to the cord if it is 120 V. Your pump sounds like 220/240 V and that is unusual that they would have a GFCI with a 2 fuse circuit. Mark

[Frank46]

Check the amp rating as well. Another thing to check is wether or not any filter or foot valve is plugged or blocked. Another thing to look for is the suction line if any. You may be starving the pump if not big enough. In theory suction lines should always be larger than discharge lines. And finally check to make sure that the pump is properly lubricated. Frank

[375RUGER]

Does anything else work properly on the GFCI circuit? I'm assuming from your description that the opener is not on a GFCI.
What size is the motor, 1/2 or 3/4? What is the current rating on it?
What determines when the motor runs or not? some sort of controller? timer? Is it all wired correctly?
Is your garage wired properly? I should say is it grounded properly and are the hot and neutral lines kept seperated? GFCIs require a functional earth connection and if there is some "disturbance" in the circuit behind the GFCI then it won't work properly.
Is the GFCI rated high enough?

[GT27]

20 amp GFCI's,20 amp fuses.Pump is 1/3 hp, not sure of amperage. House and garage wired by a certified electrician/ contractor,all wires tied capped, allJ-boxes marked(neat,tidy job) no timer, ran fine in my pond for 1 year, then this, plugged it into the next door neighbors outlet/no GFCI and worked fine..., possibly go to 30 amp fuses,yes/no?Get rid of the GFCI,yes/no? I gotta figure this out to keep our block from getting Malaria or West Nile,freakin'skeeto's,they cant land on moving water!! Thanks for the reply's guys! GT27

[The10mmKid]

Submersible Pump motors are notorious GFCI trippers. We usually replace the pump. If you feel inquisitive, open the pump up where the cord enters the housing and look for water. Most of our commercial pumps have an oil in there to balance out the water pressure trying to leak in.

Maybe set it out in the sun (on asphalt) and any moisture will dry out.

Good call on replacing the GFCI, they are too important to neglect or do away with.

I would only use a standard circuit if all the pump plumbing was metal and grounded; which probably will not happen in a pond.

'Da Kid

[JIMinPHX]

Personal protection GFCI systems trip out on 5 milliamps. That is 5 thousandths of an amp. That ain't much. They are designed to trip when there is even a whisper of a hint of a current going to ground. That is what they are supposed to do.

10ma in the wrong place can kill a person. That is why they draw the limit at 5ma.

[sharps4590]

I believe SmokedTurkey nailed it right out of the gate. 375Ruger gave you a good way to check it, just plug something else in and see if it trips the GFCI. It that device works the problem is between your receptacle and the pump.

Jim is right. A normal dew will trip a GFCI if there is a failure in the insulation of the neutral. GFCI's read the neutral, not the ground and they will work properly on an ungrounded circuit. There is a provision in the NEC whereby you can install a GFCI on an ungrounded circuit if so identified. There is even a tag provided in the GFCI box to place on the cover plate when so installed.

Your 1/3 horse motor is only consuming 250 watts and drawing a bit over 2 amps so you aren't overloaded, unless it is quite a distance from the source. 10mmKid is also correct in that submersible pumps are notorious for tripping GFCI's. As it worked fine in the past, if this were a service call of mine I'd be investigating a failure in the neutral conductor. If there is a cord and plug connection I'd check that first and where the cord enters the motor second. I'll have to agree with 10mmKid again and recommend not using the pump on a non-GFCI protected receptacle.

Oh, and yes, I am an electrician. I passed my Journeymans test in 1979 and my Masters test in 1981. Of the 36 years I've been in the trade 10 of those years were working for "the other guy" and 25 have been as an electrical contractor. We are a small shop and specialize in service work. We also do new residential occasionally, commercial frequently and do some light industrial service. Good luck, and it isn't rocket surgery, you can figure it out.

[frkelly74]

The GFCI is probably working just as it should.

[JonB_in_Glencoe]

Great info from sharps4590.
Investigate the neutral circuit.

I have a small garden fountain. During the summer, I bury an extension cord in the garden to power this. If we get rain and I try to turn on the fountain while things are wet, 'sometimes' the GFCI trips. If dry, it runs fine. My problem is the Plug from the fountain into the plug/recepticle of the extension cord...that connection is buried under a patio block and wrapped in electrical tape.

I believe SmokedTurkey nailed it right out of the gate. 375Ruger gave you a good way to check it, just plug something else in and see if it trips the GFCI. It that device works the problem is between your receptacle and the pump.

Jim is right. A normal dew will trip a GFCI if there is a failure in the insulation of the neutral. GFCI's read the neutral, not the ground and they will work properly on an ungrounded circuit. There is a provision in the NEC whereby you can install a GFCI on an ungrounded circuit if so identified. There is even a tag provided in the GFCI box to place on the cover plate when so installed.

Your 1/3 horse motor is only consuming 250 watts and drawing a bit over 2 amps so you aren't overloaded, unless it is quite a distance from the source. 10mmKid is also correct in that submersible pumps are notorious for tripping GFCI's. As it worked fine in the past, if this were a service call of mine I'd be investigating a failure in the neutral conductor. If there is a cord and plug connection I'd check that first and where the cord enters the motor second. I'll have to agree with 10mmKid again and recommend not using the pump on a non-GFCI protected receptacle.

Oh, and yes, I am an electrician. I passed my Journeymans test in 1979 and my Masters test in 1981. Of the 36 years I've been in the trade 10 of those years were working for "the other guy" and 25 have been as an electrical contractor. We are a small shop and specialize in service work. We also do new residential occasionally, commercial frequently and do some light industrial service. Good luck, and it isn't rocket surgery, you can figure it out.

[GT27]

Thanks everybody for the input,I will keep at it through "Laymans deduction" until I find and fix the problem and will post what it was,thanks again! GT27

[paul h]

Sounds like the GFCI is working as designed. Out of curiousity, how long is the extension cord, and what gauge wire? Voltage does drop with distance, especially if you are using a small gauge wire such as #14awg.

GFCI's and circuit breakers are designed to protect you from electricution and overheating your wiring and causing a fire. Generally when those devices trip it's because they are working properly. You need to find where and why you have a ground fault that is causing the GFCI to trip.

[GT27]

Cord is 10 feet,no leaks in the pump/cord. My best guess is that the current is fluctuating in the pump just enough to trip the GFCI,sooooo in turn I'm almost certain I'm going to put a non-GFCI in to run it,unless somebody has a better idea?? I just like the little extra insurance that a GFCI gives you but I understand the GFCI's sensitivity design too! It has a 20 amp GFCI in it,I wonder if a 30 would work better,anybody,your thoughts? Thanks! GT27

[Dale in Louisiana]

Guys-

Simply put, the GFCI looks at the current going out on the hot wire and coming back on the neutral. With a 'good' insulation system, these are equal. Doesn't matter if it's one amp out, one amp in, or twenty amps out, twenty amps in, if there's a 4-5 milliamp difference, the GFCI will trip.

Since your fuse of circuit breaker is tripping in the AMPS range, 10-20 amps for most circuits, a leakage high enough to trip the GFCI won't trip the breaker. 20 amps is 20,000 milliamps, or 4000 times what it takes to trip the GFCI.

As others have said, if you plug in a good tool or appliance and the GFCI doesn't trip, then the problem is in your equipment. there are some good ideas as to where to look in previous messages in this thread.

dale in Louisiana
real electrical guy (I do this for a living)

The five milliamps is chosen as it's right at the edge of the amount of current perceptible by the body as a shock.

[sharps4590]

As Dale said, the rating of the GFCI recpt. won't make any difference. It isn't tripping on overload or fault current, it's tripping because of the difference between the line and neutral. Something is amiss in your cord or motor, most likely moisture, no matter how dry it appears. Obviously there isn't much wrong because it will work without GFCI protection, but, there is enough difference to trip the GFCI. If it worked before it should work again, unless the pump motor is really getting bad. We have two fountains, one over 20 years old, and that pump still works on a GFCI. The other is about 4 years old and it still works fine. We hook up a lot of hot tubs on 2-pole GFCI's and they generally work for years upon years unless something either fails or is in the process of failing. Two weeks ago we ran the electric for a set up similar to yours, we'll see how long it runs. I hooked up a huge pond and literally a small creek for some folks 12-14 years ago and last I knew, about 2 years ago, it was still working fine on its GFCI. There is something not right somewhere in your system.

[JonB_in_Glencoe]

Cord is 10 feet,no leaks in the pump/cord.

Is this cord easily replaceable ?

I'd recommend NOT going against NEC code and powering
your water fountain pump without GCFI protection.
Jon

[GT27]

Ok,I wont go non-GFCI,I'm going to take the pump apart and look for the obvious. thanks for the input all. I'm not going to give up on it just yet!! GT27

[GT27]

115 volt/2 amp submersible,dry inside,power cord looks good! Tried it again inside non GFCI,works fine,plug into any GFCI and it trips! PITA! GT27

[smoked turkey]

Sounds like there is just enough leakage current from the motor windings to trip the GFI. As has been stated, the darn things are very sensitive to the least little bit. That is how they can save a life as it only takes about .015 amps to stop the heart. I wired a swimming pool underwater light back in the day. All new stuff but the GFI wouldn't hold. I got it to work but don't ask me how.