Weird GFCI switch issue

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dhalleron

Senior Member
Location
Louisville, KY
I know it must be something simple I am doing wrong and I need to go back to take things apart to see.

I installed a 50 amp GFCI disconnect switch, then went under the house to a junction box and came out on the same enclosed porch to a hot tub location with sealtite. When I use my solenoid tester at the 2 hot terminals on the 50 amp switch it reads 220 volts. When I put the tester on the same 2 wires 25 feet of wire away where the hot tub is it trips the GFCI switch.

I don't think I miswired something but I will go back to double check. I'll probably temporarily bypass the GFCI to make sure I have the proper voltages on all 4 wires at the tub. The tub is not there yet, so I am not taking a chance of damaging it.

Could my solenoid tester be doing something odd at the end of 25 feet of wire to trip the gfci? I was testing hot to hot, not hot to neutral or ground.
 

kwired

Electron manager
Location
NE Nebraska
Solenoid tester has enough inductive kickback the GFCI don't tolerate it?

Try same test with a low impedance meter or a 240 volt resistive load of some sort just to see what happens.
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
Solenoid tester will trip the GFCI. I think is because the tester coil has enough current flow that exceeds the 4mA rating of the GFCI tester. It could be kick back as Kwired has mentioned.

Added to edit>> I misread your post. I thought you were testing between the hot and the ground and/or neutral.
 

growler

Senior Member
Location
Atlanta,GA
I know it must be something simple I am doing wrong and I need to go back to take things apart to see.

I installed a 50 amp GFCI disconnect switch, then went under the house to a junction box and came out on the same enclosed porch to a hot tub location with sealtite. When I use my solenoid tester at the 2 hot terminals on the 50 amp switch it reads 220 volts. When I put the tester on the same 2 wires 25 feet of wire away where the hot tub is it trips the GFCI switch.

I don't think I miswired something but I will go back to double check. I'll probably temporarily bypass the GFCI to make sure I have the proper voltages on all 4 wires at the tub. The tub is not there yet, so I am not taking a chance of damaging it.

Could my solenoid tester be doing something odd at the end of 25 feet of wire to trip the gfci? I was testing hot to hot, not hot to neutral or ground.

When you test for voltage at the GFCI breaker are you checking at line or load?

If the wiring is in sealtight then maybe when you testing you move the conductors in some way that causes a short to ground/neutral. I would check with a meter and if necessary then I would meg the conductors.
 

growler

Senior Member
Location
Atlanta,GA
Solenoid tester has enough inductive kickback the GFCI don't tolerate it?

Try same test with a low impedance meter or a 240 volt resistive load of some sort just to see what happens.

That is interesting. I have not used a solinoid tester much in the last 30 years and before that there were not many GFCI protected circuits to worry about.
 

kwired

Electron manager
Location
NE Nebraska
That is interesting. I have not used a solinoid tester much in the last 30 years and before that there were not many GFCI protected circuits to worry about.
I don't know how likely it is to happen, but if it is a really cheap GFCI I suppose it has a fair chance of happening. If it were my install I will say if it can't take kickback from a solenoid tester, I don't want to know how much trouble spa motors are going to give it.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
A solenoid voltage tester was my preferred testing device for go- no go testing, and have never seen it trip the GFCI unless I was testing hot to the EGC.
 

dhalleron

Senior Member
Location
Louisville, KY
When you test for voltage at the GFCI breaker are you checking at line or load?

If the wiring is in sealtight then maybe when you testing you move the conductors in some way that causes a short to ground/neutral. I would check with a meter and if necessary then I would meg the conductors.
I was testing on load side. The owner was leaving so I had to pack up and go. I will take better tester next trip.

Sent from my SM-G930V using Tapatalk
 

dhalleron

Senior Member
Location
Louisville, KY
Good question. And it shouldn't trip testing hot-to-neutral, either. Try that, also.

It shouldn't trip hot to neutral. I was under pressure to pack up and leave because the customer was leaving for work. I can't remember if I tested that way or not. It's probably something simple or stupid I am doing.
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
171120-1418 EST

dhalleron:

Does the breaker trip instantaneously on connection of the meter, or after a short delay, or only at the instant when the meter is disconnected?

Steady state how much is your meter current at 120 V?

Where does this current level fit on the GFCI function trip time curve.

A good reference is:
https://www.nema.org/Products/Documents/NEMA-GFCI-2012-Field-Representative-Presentation.pdf

But it does not show the GFCI trip time curve. Note this is different than the trip time curve of the breaker for over current. The integrated circuit manufactures of the GFCI chip do show their curve.

I can't search for that now.

.
.
 

dhalleron

Senior Member
Location
Louisville, KY
171120-1418 EST

dhalleron:

Does the breaker trip instantaneously on connection of the meter, or after a short delay, or only at the instant when the meter is disconnected?

Steady state how much is your meter current at 120 V?

Where does this current level fit on the GFCI function trip time curve.

A good reference is:
https://www.nema.org/Products/Documents/NEMA-GFCI-2012-Field-Representative-Presentation.pdf

But it does not show the GFCI trip time curve. Note this is different than the trip time curve of the breaker for over current. The integrated circuit manufactures of the GFCI chip do show their curve.

I can't search for that now.

.
.

It trips instantaneously upon connecting the meter as if testing from hot to equipment ground. I don't know current of the meter. It's an older Ideal solenoid tester similar to model 61-076 I have used on many GFCI circuits but never on a 220 volt gfci circuit. I am going back after Turkey Day with a fresh mind and see if I just did something stupid.
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
It's starting to sound like the neutral of the hot tub wire is not connected to the GFCI breaker so when he does a test from hot to neutral it's tripping it. As he said he tested hot to hot at the breaker I think, which would not cause a trip condition.
 

kwired

Electron manager
Location
NE Nebraska
It's starting to sound like the neutral of the hot tub wire is not connected to the GFCI breaker so when he does a test from hot to neutral it's tripping it. As he said he tested hot to hot at the breaker I think, which would not cause a trip condition.
He also said that he tested "hot to hot" down stream of the breaker (or at least thought that is what he was testing between). That shouldn't trip a GFCI if both leads being tested are connected to the load side of the GFCI.

ADD: is possible he didn't test "hot to hot" like he though he did, he even admits it may have happened.
 
Last edited:

MAC702

Senior Member
Location
Clark County, NV
A load side hot to neutral bar should trip the breaker with that style of tester. He would be bypassing the neutral connection through the CB. It would be sensed as a ground fault.

Are you saying the neutral is bonded to ground? These 2-pole GFI breakers have the neutral load on the breaker, along with the hot loads. They are purposely made for equipment that has a neutral current.
 

MAC702

Senior Member
Location
Clark County, NV
Yes it is made for neutral current but that current must pass though the GFCI electronics or an imbalance is sensed.

How are you saying this will be sensed as a ground fault? The neutral DOES pass through the GFI sensor. It HAS to. Otherwise, they wouldn't provide the neutral conductor, and these would not be used for 120/240V equipment.
 
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