Could use a little help with the following electrical issue?

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jango

jango

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We have a problem with the electricity in the house. The lights are flickering on and off. When they are on they don't illuminate completely. Here's a weird one- in the girls bathroom we had the lights on. They were very dim despite being on high. I plugged in the hair dryer and the lights got bright.

We also have various plugs not working. The washer and dryer also won't work correctly. Dryer starts then dies. So, something is definitely wrong. We had the AC running. Turned it off and still have the same problems. I checked the circuit breakers and the outlets and they are all ok. Last point is this was starting to happen before the hot weather we have had the last two days. I came home Wednesday from a trip and noticed some lights flickering and the washer had error messages.

Any feedback or input on where to start investigating would be very much appreciated. Thanks
 
Could use a little help with the following electrical issue?

It sounds like a bad neutral connection. Possibly in the panel, but more likely in the meter or at the poco connection.

Check your voltages at the main panel, if there not correct go to the meter.
 
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If symptoms only appear on limited items, perhaps a multiwire branch circuit with a compromised neutral.

If symptoms are all over the house likely compromised service or feeder neutral.

If 240 volt appliances don't work and these symptoms go away when you turn off the two pole breakers, you have lost a service or feeder ungrounded conductor and are getting backfeed of the other ungrounded conductor through the 240 volt appliance(s).
 
jango said:
Any feedback or input on where to start investigating would be very much appreciated. Thanks
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Well since your profile says electrician you can open the panel and see if everything is OK.

If you find that your voltage reading from each phase to neutral are not right on the line side of the main breaker then you should just call the power company and have them check things out on their side.

It does sound like a bad neutral and most of those problems either happen in the meter base or the POCO side of things.
 
You more than likely have lost the service neutral. Too many different circuits are affected for it to be in the branch wiring. If you lost one leg, none of your straight 240V loads (like your AC) would work at all. Start by cutting off all loads, then take voltage readings at the panel buss bars L-L and L1 to N and L2 to N.

The current can still find its way back to the xfmr via the other leg, the water pipes, even the CATV braids. Straight 240V loads will not be affected by a lost neutral; your dryer motor may be 120V, and the inrush current on startup will cause a massive voltage drop and cutout.

If you dont know, a lost neutral will cause all of your 120V loads to see anywhere from 0-240V. Obviously, putting 200V thru your electronics is gonna fry them. If this is this first time you've encountered a lost neutral between the xfmr and your panel, consulting with a more experienced electrician in person would be prudent; you dont wanna figure this out on your own after half of your electronics go poof or catch fire.
 
You will need two AC volt meters,
Put one on each of your two incoming hots
use the neutral as your reference.
Now turn on a large 120v load
Does one volt meter go down
Whilst the other goes up ?
if it does this indicates a compromised neutral
Which could be in POCO territory.
:thumbsup:
 
In addition to all the good advice given so far, it's a safe bet that it's a bad neutral and in all probability anything that has an electronic digital display is probably toast by now. As mentioned in previous posts the problem is more than likely between the main panel and the utility pole. I once had a problem like this where the crimp at the utility pole corroded.
 
dmxtothemax said:
You will need two AC volt meters,
Put one on each of your two incoming hots
use the neutral as your reference.
Now turn on a large 120v load
Does one volt meter go down
Whilst the other goes up ?
if it does this indicates a compromised neutral
Which could be in POCO territory.
:thumbsup:
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Thanks everyone for the input. I did use two AC volt meters (one for each phase) to neutral at the service entrance location and was able to use a hair dryer as a test. The voltage reading went from 126V to 160V on one phase and from 116V to 83V on the other phase after turning on the 1875W hair dryer.
 
jango said:
Thanks everyone for the input. I did use two AC volt meters (one for each phase) to neutral at the service entrance location and was able to use a hair dryer as a test. The voltage reading went from 126V to 160V on one phase and from 116V to 83V on the other phase after turning on the 1875W hair dryer.
Click to expand...

As stated above, classic signs of a bad neutral.
 
jango said:
Thanks everyone for the input. I did use two AC volt meters (one for each phase) to neutral at the service entrance location and was able to use a hair dryer as a test. The voltage reading went from 126V to 160V on one phase and from 116V to 83V on the other phase after turning on the 1875W hair dryer.
Click to expand...

POCO uses a "beast of burden" to do the very same thing. Really just a a couple of large hairdryers. Loads each line to neutral with up to 80A (Mega-Beast) and a voltmeter indicates voltage on both hot legs to neutral. One up, one down indicates bad neutral. Loaded leg down and other stays almost the same, bad hot leg on the loaded side. If it happens at the meter, it's a POCO problem. Fix should be no charge. Don't wait too long to get it fixed. Mucho damage can occur.
 
meternerd said:
POCO uses a "beast of burden" to do the very same thing. Really just a a couple of large hairdryers. Loads each line to neutral with up to 80A (Mega-Beast) and a voltmeter indicates voltage on both hot legs to neutral. One up, one down indicates bad neutral. Loaded leg down and other stays almost the same, bad hot leg on the loaded side. If it happens at the meter, it's a POCO problem. Fix should be no charge. Don't wait too long to get it fixed. Mucho damage can occur.
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Beware if you load both lines the same amount you will not expose the bad neutral as easily as if you put a heavy load on one line and a light load on the other. But yes connection that has not completely failed needs a moderate to heavy load to make it go into failure mode much quicker then a light load will when trying to diagnose a problem.
 
jango said:
Thanks everyone for the input. I did use two AC volt meters (one for each phase) to neutral at the service entrance location and was able to use a hair dryer as a test. The voltage reading went from 126V to 160V on one phase and from 116V to 83V on the other phase after turning on the 1875W hair dryer.
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My SEWAG is your L-L voltage was about 242. 126+116=242 & 160+83=243
 
kwired said:
Beware if you load both lines the same amount you will not expose the bad neutral as easily as if you put a heavy load on one line and a light load on the other. But yes connection that has not completely failed needs a moderate to heavy load to make it go into failure mode much quicker then a light load will when trying to diagnose a problem.
Click to expand...

If you load each 120V leg equally, wouldnt that be the same as a 240V load? As you later write, the difference in loads would expose a bad neutral. If A and B legs were loaded almost identically, all the time, a service neutral would see nearly zero current and wouldnt be needed.

OP had a hairdryer skew the voltage almost 40V between legs. There would still need to be a load on the other leg to complete the 240V series circuit, yes? iow, if you had no service neutral, no single 120V load would work at all, correct? If the neutral had the equivalent of an 18ga wire left (not completely gone but almost there), a fairly high resi load like a hairdryer would still work, just the neutral would be hot, perhaps glowingly so.

I've gotta think in this case the neutral is completely toast or hanging on by a thread. I have to guess he doesnt have copper water pipes and a bonding connection to that and a neighbor's neutral.

At this point I'm curious as to where the failure is; at the xfmr, weatherhead, in the service drop, meter, etc. Forgive my assumption of an overhead service; it's very common here. jango, please let us know what was found.
 
JFletcher said:
If you load each 120V leg equally, wouldnt that be the same as a 240V load? As you later write, the difference in loads would expose a bad neutral. If A and B legs were loaded almost identically, all the time, a service neutral would see nearly zero current and wouldnt be needed.

OP had a hairdryer skew the voltage almost 40V between legs. There would still need to be a load on the other leg to complete the 240V series circuit, yes? iow, if you had no service neutral, no single 120V load would work at all, correct? If the neutral had the equivalent of an 18ga wire left (not completely gone but almost there), a fairly high resi load like a hairdryer would still work, just the neutral would be hot, perhaps glowingly so.

I've gotta think in this case the neutral is completely toast or hanging on by a thread. I have to guess he doesnt have copper water pipes and a bonding connection to that and a neighbor's neutral.

At this point I'm curious as to where the failure is; at the xfmr, weatherhead, in the service drop, meter, etc. Forgive my assumption of an overhead service; it's very common here. jango, please let us know what was found.
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Kind of is the same thing I was trying to say. If you put two hair dryers, one on each leg you balance the neutral and won't find a bad neutral as easily as if you put a 500 watt load on one leg and a 1500 watt load on the other leg.
 
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