Power loss

dmxtothemax

Loose connections DON'T fix them selves!!!
possibbly something has moved and the loose connection
has improved. But it is NOT fixed !!!
It will happen again, count on it.
Unless the cable guy tightened up a loose connection,
Which is unlikely.
Check and double check ALL connections between the trailer
and the supply, look for discoloration or heat damage.
If you cant find it !
get an electricain to check it.
You can bet it will happen again !!!

mpoulton

The problem you're describing affects the entire house, right? If so, then no one circuit can cause it. A loose neutral on one multi-wire branch circuit will only affect that circuit, and is much less of a big deal. The loose neutral is somewhere between the power company's transformer and your main breaker. There are not many connections that can be suspect here - maybe 3 or 4 locations at most. The connections to check are in the meter base, the outside disconnect (if you have one), and your main panel. Turn off power, undo each of these service neutral connections, and re-connect them securely. Clean them up and use anti-oxidant if they are corroded.

Be careful doing this. If you have neighbors with similar problems, your neutral could be carrying their load current (transferred to your house through the cable TV wiring, water pipes, etc.). If so, then your neutral will carry current even when your power is off, and could shock you when you disconnect it. It would be prudent to check your neutral with a clamp-on ammeter before you disconnect it.

When you're done and the power is back on, you can check your cable TV service line and the ground on the water heater with a clamp-on ammeter to confirm no current flow.

Hourglass52

With out being there. I am finnished with this one.

carlko

A followup and some questions:

My power went out completely and I found I only had 45v on one of the service cables, 0 on the others, where they attach to the inside box. I had full V where they left the outside box. They are underground through a PCV conduit.

I temporarily disconnected them and hooked a 12/2 romex up and everything worked fine.

I then pulled some heavy duty cable that used to run the central air, which doesn't work, and used that to connect the outside to the inside. Everything is working fine and I'm in the process of digging up the old cable, which I will fix or replace. BTW, the old service cables are aluminum outside but copper inside, so there must be a splice underground, correct? Is that the likely trouble point?

If you remember, there was a romex cable running from a separate 25A outlet outside to the water heater, and when the ground wire was disconnected I got the power loss. I noticed when I disconnected this from the outside box (I now have the WH hooked up correctly to the inside service box), that the ground wire was connected to the neutral bus. Do you think this was the cause of the power loss - it would have been an open neutral when the splice came loose?

At the outside box there is a ground wire from the meter base to a rod that is sunk in the ground, but I don't see a ground anywhere else outside.

My questions are:

Is there any way to test for an open neutral? I have no symptoms.

Is there any way to test for correct grounding of the system?

Thanks for all your help - I think I've about got this fixed and would have had a lot more trouble without this forum.

bob22

You really need to get someone on site who can help with this; like a licensed electrician. You can't just replace service cable with "heavy duty cable" without potentially causing a fire or death as you'll be playing with unfused voltage when you go to replace it and IF you dodge the death bullet, the new cable will be in place without proper over current protection (too small a wire for the amperage protection of the breaker), a recipe for fire.

dmxtothemax

Using a volt meter,
If you are reading correct voltage from active to ground,
But low or no voltage from active to neutral,
Then this indicates no neutral or poor neutral.
You will have to trace out your neutral line.
Avoid joints in underground cables if you can,
They can cause many problems,
Better and more reliable to run a new one piece cable.

carlko

Just for clarification.

The old service cable was 1/0 many stranded aluminum outside with about 6 stranded copper inside, so probably spliced underground.

The new cable I have attached is exactly the same as the old outside, only now no splice. I had to break 5 or 6 strands off the hot wires to attach to the load center as it was too big a cross section to fit in the lug. The neutral is slightly smaller though the same kind as the old cable outside - don't know the rating but about 10 aluminum strands.

Also, this is a mobile home as I said - the outside box that is fed by the meter has a cutoff so I can kill all power to the trailer to work on the inside box. I DO NOT work with live wires or any wire if I don't KNOW it has no voltage.

Edit: BTW, the cutoff outside also kills all power to the service cable at the outside box - the cables attach below the cutoff.

jbfan

Cutting strands off to fit a connector is never a good thing to do.

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carlko

My only other options were to use much thinner cable or spend about $250 for new. Why won't a cable with 15 or so strands intact be better than a cable with 8 untouched?

carlko

I dug up the conduit and opened it up. The 1/0 AL cable that ran from the meter into the conduit was joined to 6/3 copper underground by just using electrical tape, about 4' into the conduit. One of the hot cables had degraded the tape and was making poor contact, which is why I wasn't getting full voltage at the load center. I don't think I ever had an open neutral - I never had a power surge, just a power loss under certain circumstances.

Right now I have the 6/3 run through the conduit above ground, no splice. It goes to a 100 amp circuit breaker inside.

My question is whether this is a code violation - do I need heavier gauge cable to comply? I don't think I ever draw more than 60 amps at any one time, and probably never more than 30 or 40 for any continuous period. This trailer has basically been operating on the 6/3 for a long time and there is no sign of over heating, so I feel there is no safety issue, just whether or not an inspector would allow it.

I have enough 1/0 to run continuous but I don't think I can get it through the 1 1/2" rigid conduit - so I would either have to buy new conduit (maybe 2") or run 2 conduits, or new cable (maybe #3 copper?) or install a 60 amp breaker, which might require a new load center as I don't know if I can find a breaker that will fit.

Also, is there any requirement that it run underground? I live in Louisiana, and I can tell you from digging up this conduit there is a lot of water in the ground. The 2' trench I dug is full of water right now from rain that ended 4 days ago.

joed

6/3 cable is only good for 60 amps.

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