test your circuit before connecting to breaker

[Ford2001]

Recently an old time electrician call me, and since we were good friends,
he want to show me something he does, before connection, the Power
Circuits also call home runs, to the electrical panel circuit breaker./

Here were only talking about single pole breakers.

One breaker feed a stranded duplex receptacle.

The 2nd. breaker feed to the line side of a GFCI duplex receptacples.

This is was one of those D.I.Y. wiring jobs, were the D.I.Y. didn't want
to tie in all the circuits into the electrial panel. So he call old Pete,
and Pete, said okay.

Here what Pete does before connecting a circuit to the electrical panel/\.
He wire nuts the end of NM-B cable to a cord set without a female end.

He then ties white/white, black/black & ground/ground and plugs it into
a normal breaker receptacle. This was a test. If the circuit pass this
this test, he would then plug the circuit into the receptacle protected
by a GFCI. So far on this job, 90% of the circuits were passing.

But when I arrive at his job, he said watch this. He plug into normal
receptacle, and it pass this part of his test. NOW, when plug, into the
GFCI protected receptacle, the GFCI click off.

Then Pete look at me and said, D.I.Y.'s only care that the circuit will bring
power to the light outlets and the power receptacles, they don't care
of they wire the electrical properly.

Pete found the problem. Correct the wiring, and the GFCI test receptacle
held this time.

Pete would tell me what he did, he said I should go home and study, and
tried to come up with a answer.

[Lakee911]

This sounds like a homework problem. I don't think anyone here will answer it for you. Why don't you take a stab at it and then we'll help w/ the answer?

[hj]

I cannot see where that test does anything that a continuity/ohmmeter would not, and without having to wire it to an extension cord.

[Ian Gills]

I'm guessing a test for reverse polarity.

I just take care with what I am doing.

[hj]

Unless you are using a tester that checks between the hot, neutral, and ground, you will not find reversed polarity by plugging a circuit into a hot line.

[frenchie]

GFI's test one thing, and one thing only.

But I agree with Jason:

This sounds like a homework problem. I don't think anyone here will answer it for you. Why don't you take a stab at it and then we'll help w/ the answer?

[Scuba_Dave]

Someone on another site was posting questions - also homework questions

[drick]

Hmm, this is a somewhat difficult homework question IMO. Although the answer is in the question itself someone without practical experience might not realize it.


>>Then Pete look at me and said, D.I.Y.'s only care that the circuit will bring
power to the light outlets and the power receptacles, they don't care
of they wire the electrical properly.

-rick

[Lakee911]

Hmm, this is a somewhat difficult homework question IMO. Although the answer is in the question itself someone without practical experience might not realize it.


>>Then Pete look at me and said, D.I.Y.'s only care that the circuit will bring
power to the light outlets and the power receptacles, they don't care
of they wire the electrical properly.

-rick

Yup.

Guy never even came back ... probably because we didn't give him the answer.

[Ford2001]

I write this now, because I felt I didn't write my original Thread very well.
I left out something. I believe it was, that Pete was wiring new circuits
into the house existing panel box.

The second thing left out, was there were two circuits inside one outlet
box. One circuit was pre-exisiting and feed power to a receptacle used
by a basement sump pump. The 2nd. circuit, new, was being splice at
this outlet box. This is a new circuit, and the one that trip the GFCI.

I asked Pete was the sump pump circuit was on at the time of his test, he
said it was off.

What I know about GFCI's is that they measure current on both legs of
a 120 volt circuit. But with no load on either of the two circuits, and
just the new circuit splice inside the sump pump, outlet box, why did the
GFCI test receptacle trip.

Thanks to everyone who took a look at this Thread. I am very sorry that
I left out some details, now looking back might have been helpful in solving
this riddle.