Quick Question - Electrical Box Wiring - Calling all you electricians!!

[mopar_nut_440_6]

I am just wiring my garage and wanted to test my connections prior to my inspection next week. In the past I have used an extension cord plugged into my house outlet to power the box with 110 and have been able to run lights etc.

I have not done this in 15 years and seem to be missing something as when I hook up my cord to the box I trip the breaker immediately. I suspect that it is the positions I am connecting the wires from the extension cord to.

I have an old extension cord with the female end removed. I am connecting the black wire to one side of the main breaker (circled in green in the picture), the white to the neutral bus (circled in red in the picture) and the green wire to the ground connection ( circled in blue in the picture).

If I hook up just the black and white wires it does not trip the breaker but I also do not have power to my outlets. As soon as I connect the green wire to ground the breaker in the house trips.

Is there a better way of doing this? Am I connecting my electrical cord wires to the wrong spots?

[Magnumcharger]

Lets see your wiring at your outlet. The panel wiring seems fine. I'm betting both of your wires are being connected on the same side of the outlet....

[Tilar]

It looks like you have the common and ground tied together. Your white should be tied in where I have it marked "Or here" The bar that is marked "White here?" apprears to be tied to the ground bar above where I have a little green scribble right between your red and blue circles. It may not really be that way, but from my perspective it is.

[2Gunz]

The wiring looks correct.

Is the breaker you are tripping a GFI?

Having the ground and white together shouldnt trip the breaker.
I suspect someplace the black and green are coming into contact with each other.

Is the other end of the extention cord wired correctly?

Are you removing the main wires when you attach the extention cord? you should.

It should also be noted that to get power to all the outlets temporarily you will need to jump together
the red and black main inputs. Make sure the new 208 breakers are off and dont get turned on unless nothing
is connected to them.

Does it trip with all the beakers off?

[dodgecharger-fan]

Are you removing the main wires when you attach the extention cord? you should.

As magnum mentioned, double check the wiring of the extension cord and the outlet that it is plugged in to just to be sure - but if something were messed up in there, you should have come across it in the past while using the outlet. It really depends on how it is used. (I had a circuit in my old house that was delivering 220 to a regular wall outlet and didn't know it for years because we never used it.)

After that checks out okay, test your garage wiring with all of the breakers turned off to eliminate and possible wiring problems out in the circuits.
Then turn them on one at a time. If one trips, check that circuit... etc..

That process of elimination should get you to a point where you're powered on and no breakers are tripped.

It wasn't said how long of a run or what gauge of wire is in the extension cord, but do the initial testing with no load on the circuits to avoid excessive draw.

[mopar_nut_440_6]

It looks like you have the common and ground tied together. Your white should be tied in where I have it marked "Or here" The bar that is marked "White here?" apprears to be tied to the ground bar above where I have a little green scribble right between your red and blue circles. It may not really be that way, but from my perspective it is.

It is a little difficult to see but the neutral bus and grounds are not connected.

The breaker on the house is a GFCI. When I am powering up the box all the breakers are off. The extension cord has the factory molded end on it and is about 20 feet long and does not trip the breaker until I hook the green(ground) up in the breaker box. I have gone as far as to unhook all the runs which could "potentially" have an issue such as anything with switches. I did leave the outlets wired in as they are pretty basic and I would expect no issues there but will unhook them all and then test. I had also not jumped my red and black when hooking up to the box as I was only testing on the one side of the buss but will do this as well.

I did not unhook the main power cable when I did the test as it is not connected on the opposite end to the main in the house yet and the wires are all covered so I would not expect there to be a problem there.

Thanks for the responses, I just wanted to make sure what I was trying to do was correct.

[Todd Wilson]

Try your test using a non GFI plug in.   Those things do some funky things sometimes. They are best for hair dryers and curling irons in the bathroom.   I have heard of them doing freaky things with radio equipment that is plugged into them. The radio equipment has its own ground and some of the old tube radios will not even work on them.


Todd

[Dodgecharger74]

Looks like the 100 amp feeders coming in bottom are correct  Why not turn on the 100 amp breaker feeding these?

[skip68]

Is the GFI wired correct ?

[mopar_nut_440_6]

Looks like the 100 amp feeders coming in bottom are correct  Why not turn on the 100 amp breaker feeding these?

I have not hooked it up to the house main yet. I need to wait for the inspector to check my rough in. It is going to be a pretty large job to unhook the existing wiring for my other garage and reconnect this one so I do not want to do it twice.

[mopar_nut_440_6]

Is the GFI wired correct ?

Appears to be but I did not wire it. I know it works as my son plugs his block heater into it during the winter. I will give another normal outlet a try.

[dkn1997]

No offense, but why are you even trying this?  it's obvious you had someone with a license wire this panel for you, just turn on the breaker that feeds it.

I see no need to test this panel with an extension cord. 

[mopar_nut_440_6]

No offense, but why are you even trying this?  it's obvious you had someone with a license wire this panel for you, just turn on the breaker that feeds it.

I see no need to test this panel with an extension cord. 

Thanks for the compliment. I wired the panel myself but this is not the first job I have done. I actually have built and wired three garages and one house but the last one was 12 years ago so I am a bit rusty. I wanted to test all the wiring prior to the inspection just to be sure all was good and to save the inspector a second trip.

[RECHRGD]

Something is grounding one or both phases in the panel.  Unhook the main wires from the panel and check for any continuity between the hot wires and ground and/or neutral.  If those wires check out good, then ohm out the panel from ground to both phases with the main turned on.  If everything checks out open, then your back to a bad GFI or cord.  Good luck, Bob

[2Gunz]

I suspect this is a GFI issue but more on that in a moment.

The fastest way to get to the bottom of this is with a meter.

If you dont have one you can pick one up for like $10 bucks.

Disconnect the mains including the ground.

Turn all the beakers off. Make sure nothing is plugged into the outlets anywhere.
Turn off all the light switches. Turn off all hardwired devices if they cant be turned off disconnect them.

Get the meter and set it to ohms or continuity (most meters its the same setting).

Touch the 2 probes together and you should get zero's or a tone or both if the meter is working correctly.

Touch one of the probes to the black the other to the red. It doesnt mater which probe color you use where.
You should get nothing. NOT zero or a tone. Just open.

Repeat this doing all the possible combinations of The Black, red, white (in your case blue) and ground wires.
Any wire to any wire should be nothing.

Begin turning on the breakers one at a time. And for each breaker do every combo.
You should get a reading of nothing. If you do find a reading you have found your problem.



The GFI thing.

GFI outlets measure loss of power. As in the black leg is putting out 5 amps and the white leg is returning 5 amps all is well.
However if the black leg is putting out 5 amps and the white leg is returning 4 amps it assumes there is a problem and "trips".
As in you are in water getting electrocuted and part of the power is going into the earth or some metal object.

They are brilliant because a "normal" breaker or outlet doesnt care where the power is going as long as its not over whatever the breaker is rated for.
So with a normal breaker you could be killed as long as your death doesnt require more than 15 or 20 amps.

The problem is they work poorly in branch circuits. As in the power is going to many places. It screws with its testing system.
And what your trying to do is the worst case scenario. Could it work? maybe.

But before just trying a different non GFI outlet and making sparks I would meter it all.

In my earlier post I suggested you connect the two hots together to make all the outlets work.
You would need to do this because in MOST cases the RED and Black leg are every other connection on the box.
NOT black on one side and red on the other. Its done this way so you can get 220v out of a single double breaker.

Anyway Good luck and dont hurt yourself. 

[mopar_nut_440_6]

Thanks 2gunz. That was a great explanation.