Power loss
 

When anything in my 20 year old mobile home draws more than a few amps the lights flicker and appliances, though running, lose power - for instance, the oven won't heat properly. I suspect a faulty breaker box. How can I troubleshoot this? Thanks

Sounds like there's probably a loose connection somewhere. Since this is a mobile home, you have a main disconnect outside, right? Start by opening up your main panel and looking at the incoming wires to the main breaker. See if it looks like there's any burning or discoloration. Loose connections tend to heat up. If you can shut the power off outside at the disconnect, try tightening down the lugs on your main breaker, and also the main neutral connection.

It could also be in the main disconnect outside. With the disconnect off, you can safely tighten the LOAD terminals and neutral. The LOAD terminals are the ones holding the wires heading to your main panel inside. Don't touch the LINE terminals bringing power into the disconnect, as they always have power. If you're unsure which are which, or don't feel comfortable working near live wires, leave the outside disconnect to an electrician.

It is also possible the main breaker is going bad, or has a bad connection to the bus, but loose wire connections are an easy starting point. What brand is your main panel?

Thanks for the reply. I can't explain it, but the problem seems to have fixed itself. I can turn on all my appliances now and there's no dimming at all, whereas one day ago just a 500 watt space heater was causing a noticeable power loss.

The only thing that's happened is the cable guy replaced my outside cable. I've had catv and internet problems about once a week for the last 6 weeks - I would lose the inet, then the cable, then both would come back within a few hours. I replaced all cables and connectors inside but still had the problem. The cable guy said the cables were very old so he replaced them, inet and tv are fine, and now my electric problem seems solved.

I don't see how the two can be connected, but for now am very happy everything's working. Thanks again for the quick response and will try your advice if it pops up again.

You should definitely consider evaluating this further, perhaps with the assistance of an electrician.

The fact that the issue went away the same time as the cable line was replaced makes me very nervous. Sometimes, what happens is that your main neutral connection gets loose, or the wire is partially broken, and current starts taking other unintended paths back to the power company transformer, such as water pipes, gas pipes, or cable TV lines. I would not entirely rule out the possibility that you have a borderline neutral connection. This would be a pretty simple and quick test for someone with a clamp-on ammeter.

Do you mean a loose connection at the main box outside?

BTW, all my water pipes are plastic and there are no gas pipes, I'm all electric. Would there be a danger from any of my outlets or appliances?

I thought I would follow this up since I found the problem. There's a dedicated 3-wire romex running from the outside box to the hot water heater. It's above ground and has 2 splices. I found at one of the splices that the ground wire had come loose. With this reconnected everything seems fine. Of course, it's a dangerous condition as is, so I'm going to replace the romex, encase it in plastic conduit, and bury it. Thanks for the help.

okay, so instead of your neutral current going through the cable wires, you've determined that it's going through the outer shell of your electric water heater.

Why are you so determined to bypass the problem instead of fixing it?

Your cable lines needed to be replaced because they overheated from your neutral current running through them.

Your water heater splices failed for a similar reason.

FIX YOUR NEUTRAL CONDUCTOR OR CALL THE POWER COMPANY TO FIX THEIRS before you are indirectly responsible for an EXTREMELY LARGE PROBLEM.

Um, that doesn't sound good. If you had bad splices in a ground conductor to your WH that was causing voltage fluctuations, that tells me that your neutral current is trying to carry on the ground. Replacing and burying the wire to the water heater is probably a good idea, but I don't think that's the root cause of your problem.

You WH may be wired incorrectly, or you have bad neutral connection somewhere between you and the PoCo transformer (maybe not even on your side of the meter). Those are just a couple of possibilities, but something is definitely not right. Call the PoCo ASAP and get them to check their wiring, and call an electrician to come out and check your panel(s) and wiring.

No offense, but your description of the WH hookup makes me think that there are some other potentially dangerous gremlins lurking in your system.

So far, you have only covered up symptoms. You have a much greater problem that still exists, and has not been solved.

It sounds like a bad neutral in your feeder cable ... and a neutral to ground fault condition exists.

Unplug your dryer and range, and see if those problems return.

You can't bury romex. It must be wet rated cable or wire.

An open ground to the water heater should not have caused your problems. There is another issue that that connecting ground is camouflaging. Open neutral is a likely possibility.

Everyone seems to think the real problem is a bad neutral. I would appreciate someone explaining in more detail what that is, how I find it and how to fix it. I'm a complete newbie with this stuff. Also, neither the stove or dryer circuits have appliances connected. Thanks.

http://cr4.globalspec.com/PostImages...486AE1014F.jpg

Hydro ------> House

Basically power comes to your house with 3 wires, two hots, one neutral. The potential between both hots is 240 volts, while the potential between any hot and the neutral is 120v. The neutral is also bonded to the ground, so it should have 0 potential with the ground. You can use the ground as a neutral and it will work (BUT IS NOT OK!) So a bad neutral could cause power to go to ground depending on situation, instead of to the neutral, and depending on what path is being taken to get to the ground, results can vary a lot as said path may not be rated for that load. Big appliances such as ovens, dryers only use the two hots so they are not affected by a bad neutral. When a 120v appliance needs power and the neutral is not available, another potential hazard is that instead of finding a path back to ground it finds a path through an appliance that is plugged through the other hot, this puts both of these appliances in series, at 240v. This can cause lights to dim, or get bright, appliances to fry, or not get enough power. Lot of weird stuff can happen.

Basically, you really want to check that neutral and fix it properly if that's the problem. Don't want to burn the place down. :o

The neutral functions a return path to the PoCo for "used" electricity. You have two incoming hot legs with a combined potential for 240V, with one neutral leg returning. The potential for return on either of the hot legs through the neutral is 120V. When the neutral fails, the returning current from one of the hot legs will attempt to divert through the electrical ground, but if the ground cannot sustain that amount of current, the current can attempt to return via the remaining hot leg, causing an imbalance in the voltage of the two hot legs. This results in the dimming/brightening effect you have described. The dimming/brightening effect will most likely occur when a high-current 120V appliance (microwave, vacuum cleaner, power tool, etc.) is turned on and the high amount of current cannot successful return through the neutral.

All of the evidence you've presented indicated a failed neutral with current attempting to return to ground (CATV, WH hookup, etc.). Until the neutral situation is resolved, these items (as well the rest of your grounding system) will continue to degrade and fail.

If you are indeed a complete newbie, this is a problem that is beyond your capabilities. A failed neutral is not where you want to cut your teeth learning about wiring.

Your first call should be to the local PoCo to have them come check the connection between the pole and your meter, and you should do it NOW. PoCos take this type of failure seriously and usually will be onsite the same day. In many cases, the problem is on the PoCo side of the meter and they legally are the only ones authorized to correct the problem.

If everything checks out on the PoCo side, then your panel needs to be checked by a licensed electrician. It could be as simple as a loose lug in the panel, or as serious as a degraded panel or improper wiring.

Your description of your WH hook-up makes me think you have some potentially dangerous wiring which may be independent of the neutral problem, and it may not be limited to just the WH. Do yourself, your family and your insurance company a favor and call the PoCo and an electrician to sort this out and make sure *all* of your wiring is sound and legal.

Please also check back here with an update so we know you're still alive. :laughing:

:laughing:

I've decided to buy a multimeter and Wiring a House by Cauldwell, as well as read a lot and look at videos. Don't worry, I know how to turn the electric off at the meter, and inside as well, and use a multimeter, so I'm going very slowly. I look on this as if I was completely re-wiring, so I will go slow and if I have any problems will check back here.

I did look in the breaker box, and there are two main lines along with two large white wires I assume are the neutrals - they look well attached but I haven't done anything yet.

Thanks for your help - I'm doing this because I have a lot more time than money, so I'm in no hurry, and I also want to understand it better.