Lost Power - Cant Locate Fault

tool junkie

Hi Guys
This one is beyond basics, for me anyway. We have a little problem at our mobile jobsite office. No power.

Here is the layout....
Service enters to a single breaker (30A) (before the meter) right next to the Meter. Then it enters the meter. Exits the meter then into the trailer. There is no panel at all other than the single shut-off box before the meter. Power goes straight to the outlets. This is odd to me but thats the case.

Testing...
I am getting 120 into the meter and 120 out of the meter and into the trailer but after that there is no current at the switches and recepticles. HOWEVER my voltage detector is sensing voltage there and throughout the wireing yet there is no current. I am picking up voltage on both the hot and the comon wires and there is continuity between them.

Is this a short or crossed wires/polarity? If so then why isnt the breaker before the meter tripping? Could the meter be bad?

Can I get a tip on the easiest way to trace the fault

tool junkie

There is no fuseable link between the meter and the switches/outlets. There should be a breaker panel but there isnt. At least then I could look for a tripped breaker and thereby isolate the fault easier but there isnt. So if there is a short it affects the whole system.

SO I have 120 going into the building but no power at the boxes. Yet the voltage sensor is picking something up.

OK I'll put a multimeter on it to see if there is any amount of voltage.

I need to resolve this soon, its hotter than hell today.

Bkessler

YOur electrician will have it figured out in ten minutes.

tool junkie

Yeah once he gets here some day. Hey thanks for the help wise guy

Well Im a GC, so what are we doing here, helping eachother out or knocking eachothers professions and level of knowledge is certain fields?

Timster

Grab a 120v tester, and test every single plug and outlet. I have no idea how they wire those things, but if the wiring is in series instead of homeruns and dedicated circuits, you may have a dropped neutral right after the meter...

You will giggle when you find out what the problem was, whatever it is; I usually do, tee hee.

Then you can just giggle and fix it.

tool junkie

Its in series. Everything tests dead. Inspected all the outlets and wiring looks fine.

wireless

Open neutral. Test hot to ground.

220/221

I suspect you are testing to neutral at the outlets and to ground at the meter.

mdshunk

You probably need to install more 120. Sounds like yours ran out.

MALCO.New.York

Yeah but those per gallon prices are getting so damn high. Remember this is a Trailer........Not a McMansion!!!!

tool junkie

nope. tested to neutral at the meter too.

Anyway I found it. We pulled down the insulation to expose the runs and traced the lines. looks like some connections got mangled in transport to the job site. I put in a new jbox and spliced in some new wire, buttoned it up and everything is good now.

Bkessler

Sorry tool junkie, but it is not safe for a non electrician to be working on a situation like this. General contractors doubling as the electrician usually ends up in disaster.

tool junkie

LOL If I said that to my boss he would give me a half smoked cigar a one way ticket to the unemployment line. if I had to wait for a sub to show up every time we had a jobsite emergency I wouldnt have my job for very long. Especially when it means the office is down.

Timster

Exactly. You did a good job, dude...

By the way, I have a friend who is a C-10 and a general contractor... I guess he don't know nuttin' about electrical.

I'll make sure to tell him to stop wiring new home builds, among other things, since he is a general contractor.

I am a general contractor too, and I know my way around electrical a little bit...

Good for you junkie for finding the problem...

tool junkie

and the black wire is the ground right? So where the heck is the hot wire, you know, the red one? Why is it I can never find the red wire

Magnettica

Ha ha, big funny joke, huh.

Well, it's not a funny joke when the HO goes to a load of laundry, touches the machine and dies of an electrocution because it was improperly grounded.

Mind you, we are discussing an open neutral and that of course is a grounded conductor but you probably already knew that.

Bkessler

In other words Tool Junkie you may have fixed the problem but do you know exactly how dangerous the situation was? A loose neutral wire has the potential to cause some major injuries. And I have seen almost everything metal in a home become energized with 120 volts because of one loose wire. Now imagine that same situation with a wet kitchen floor, bare feet and touching your sink or oven.

neolitic

You guys have really good points,
however, it doesn't sound as though
you actually read the OP.

Very few of the office trailers I've seen
on job sites come equipped with laundry rooms
and full kitchens.

Magnettica

Like BK said, if not the laundry machine, how about the kitchen sink, stove, refrigerator, or plumbing pipes? The point is it's no joke, and I know u already knew that. One of the things that amazed me early on was how an entire aluminum sided house could become energized because I've seen that too.

neolitic

I was just saying that the examples
you used don't apply to an office trailer.
(Not the ones I've had to work in anyway)
If you want him to get your point
the siding works, the stove and
washing machine don't.
He's trying to get the office trailer up
and running, but he still needs Sparks
to come check things out in the end.