Solve This Service Call : Chapter 3 - Electrician Talk - Professional Electrical Contractors Forum

480sparky · 07-31-2009, 12:19 PM

Phone rings this morning. Owner of a mobile home park. Lot 632 lost half it's power.

So I head over and talk to the lady of the house. She says half the power went out last night, so she turned the breaker off in the house and turned it back on. Still no power in half the house. She turns the main off again, and keeps it off for a couple minutes. Turns back on, and still only half the power.

So she goes out to the power box outside and taps on the cord end that feeds the house and the power comes on. By power box, I mean this:

Each house has one of these fed from a meter/main. They usually have 50a fuses in them to supply power to a NEMA 15-50 ('range') receptacle.

This is in a park that was built and wired in 1962, and pretty much everything is original.

What would your next step be?

drsparky · 07-31-2009, 12:25 PM

Look in the box.

480sparky · 07-31-2009, 12:29 PM

Quote:

Originally Posted by drsparky

Look in the box.

Well, yes, but after I turn off the power. So I go out to the meter main and pull the disconnect.

I root around in the power box, looking for loose connections. Although the AL URD does not have de-ox on it, they're not loose. I can still turn the terminals about ¼ turn, but that does not appear to be the problem.

crazyboy · 07-31-2009, 01:06 PM

Check your voltages there and see if it all checks out. Also, check the receptacle and plug, trailer homes have a good thing with burning them.

480sparky · 07-31-2009, 01:25 PM

I knew power was on when I pulled the fuses out of the meter/main since the AC compressor was running.

I pulled the cord end out of the recep, and it looked almost new.

seo · 07-31-2009, 02:15 PM

Terminals on back of receptacle probably were over tightned and one of the terminals broke.

te12co2w · 07-31-2009, 02:16 PM

So you have 120/240 at the receptacle? Is there good voltage at the trailer loadcenter with the cord plugged in? If yes, the problem is in the trailer. If not, then check voltage on line lugs of box where cord plugs in.

leland · 07-31-2009, 02:25 PM

Connection at meter or the box. Maybe the cord cap or inside.
That narrows it down.

Glad to be of help.

If she kicked the box,I would start there.
Is the Finnigan pin installed?

drsparky · 07-31-2009, 02:29 PM

I don’t know if this is a red herring but the receptacle is a NEMA 14-50 not a NEMA 15-50. I don’t think 14-50s have been around since 1963. Possibly we have a “bootleg” jumper to convert three wires to four wires?

480sparky · 07-31-2009, 02:30 PM

Quote:

Originally Posted by drsparky

I don’t know if this is a red herring but the receptacle is a NEMA 14-50 not a NEMA 15-50. I don’t think 14-50s have been around since 1963. Possibly we have a “bootleg” jumper to convert three wires to four wires?

14-50 is a standard 'range' outlet.

15-50 is for three phase.

Now the fun begins.

After checking for loose connections in the power box (and not finding anything), I go to turn the power back on at the meter main. It's a 100a pull-out fuse block, and the dumb thing just won't go back in. It stops dead before it makes contact with the copper buses inside. I work and work and work with it, and it just will not go in. It looks like it's not even close to lining up. Just like trying to put a square peg in a round hole. It just will not go.

I think "WTH? This stupid thing just came out of there! Why the he11 doesn't in go back in? It can't be that difficult!" I mean, I'm really getting PO'd at this point!!!!

I finally solve the mystery...... why it won't go back in, and get the main fuse block seated properly. See anything wrong here?

So................ With the main back on, I go back to the power box and check for power.

One leg is dead.

drsparky · 07-31-2009, 02:42 PM

If the power is on when the photo was taken the guts were installed upside down 46 years ago, or someone was playing in the box that didn't know what they were doing. I would look there.

480sparky · 07-31-2009, 02:59 PM

Quote:

Originally Posted by drsparky

If the power is on when the photo was taken the guts were installed upside down 46 years ago, or someone was playing in the box that didn't know what they were doing. I would look there.

I stood there in complete amazement once I got it to go in...........upside down!

I was a bear to get out to begin with. I had to take a screwdriver and pry it out. So no one had been monkeying with it for quite some time, much less the HO last night.

Anyway, as I start to take the screws off the cover, I start hearing a light buzzing sound.........

drsparky · 07-31-2009, 03:50 PM

Quote:

Originally Posted by 480sparky

i stood there in complete amazement once i got it to go in...........upside down!

I was a bear to get out to begin with. I had to take a screwdriver and pry it out. So no one had been monkeying with it for quite some time, much less the ho last night.

Anyway, as i start to take the screws off the cover, i start hearing a light buzzing sound.........

Bees nest, run!