Mysterious electrical problem - Help?

Reply

  #1  
Old 05-06-16, 02:52 PM
Member
Thread Starter
Join Date: May 2016
Location: USA
Posts: 7
Received 0 Votes on 0 Posts
Unhappy Mysterious electrical problem - Help?

Hello:

This is my first time posting to this forum, but I have often visited to learn from others. Now I find myself in the middle of an electrical mystery that no one has been able to solve, and I'm wondering if this forum can help. I've had the problem assessed by our power utility and a professional electrician, so I'm running out of ways to seek help.

The issue began several months ago when our LED television began to intermittently buzz loudly when we were watching TV. It could last for a few seconds, or it could go on for an hour. It varied. Eventually, we realized that it was happening even when the TV was turned off. We had the TV evaluated but it was not a TV fault.

Flash forward to the present, and the issue continues. But it's not just the TV anymore - all sorts of things in the house will buzz intermittently, and all at the same time. This includes LED lights, phone charges, computer transformers, the coffee maker and all GFCI outlets. We have confirmed that the issue is not confined to one circuit and it is independent of all circuits on the subpanel - you can isolate any circuit at the subpanel and items powers from it will buzz even if all other circuits are off. We've also ruled out dimmers because the issue persists even if circuits will dimmers are powered off. It happens under light and heavy load, and it's getting worse (the TV is unwatchable when it's happening). So, we know it's not an individual circuit or device that is to blame.

Our utility (PG&E) has inspected their meter and the power drop connections at the pole (they even replaced them), but voltage checks out. The suspicion had been a loose neutral, but that's not the case (at the pole, at least), Our electrician inspected our main (200 amp) and sub panel (150 amp) and found no issues. Neither of these inspections occurred while a "buzzing" event was happening, which is just dumb luck - the issue hasn't occurred at the right time.

I will note that the electrical breakers in the subpanel and main (which is outside of the house) also buzz lightly during these events. For this reason, we currently suspect that the main panel or maybe just the main breaker are failing (we replaced all other breakers in the main, including the sub-feeder to be sure). It's an expensive fix to replace these, and we don't have any guarantees that it will work. No one has found proof of a problem.

One other hint: one APC surge protector in the house has an "overload" light that comes on during the buzzing. The protector isn't actually overloaded at the time - the light comes on even if just one item is plugged in, and it doesn't matter what that is. But when the buzzing stops, the light goes back off. Maybe this tell us something?

Like I said, the professional and the utility are stumped. The suggestion is to throw money at it, so this is my last effort to identify a likely culprit before we replace the whole main panel. Any thoughts? Thanks!

-Tony
California
 
Sponsored Links
  #2  
Old 05-06-16, 03:55 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Who is the manufacturer of your main panel? Any corrosion on the bus bars? Does anyone else in the neighborhood have the problem?

My thought is radio interference either ham or cell tower. You might want to contact the FCC and ask them to investigate.
 
  #3  
Old 05-06-16, 04:21 PM
Rough Rooster's Avatar
Member
Join Date: Feb 2014
Location: USA
Posts: 401
Received 3 Votes on 3 Posts
A possibility to consider if you are within a couple of miles of a petroleum pipeline would be the anode protection system they use to slow pipe corrosion. When these are not operating properly all kinds of weird problems occur.

Does a nearby neighbor have a bootleg welding system they use occasionally?

Any solar charging systems in neighborhood? One of them could have a bad sine wave generator feeding 'dirty' power to grid.

Had an EMI problem several years ago that was a cracked insulator on high voltage lines feeding home.

RR
 
  #4  
Old 05-06-16, 04:28 PM
Member
Thread Starter
Join Date: May 2016
Location: USA
Posts: 7
Received 0 Votes on 0 Posts
Thanks for the reply!

The panel is Eaton/Cutlet Hammer. No obvious signs of corrosion on the bars, and we did try swapping the sub-feeder to a new spot on the bus (no improvement)

Hadn't considered interference from ham or cell tower. Others in the neighborhood would be complaining, I would think. Is there any way to confirm this before contacting the FCC?
 
  #5  
Old 05-06-16, 04:30 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,219
Received 477 Votes on 447 Posts
I have a xxxxxx glitch monitoring device that monitors both legs of the power for voltage sag and phase drift as well as noise on the hot lines. They are not easy to come by.

I don't see an easy remedy to your problem but what I can recommend is to purchase an inexpensive meter to check voltages when the problem occurs. It gives you a starting point.
 
  #6  
Old 05-06-16, 04:31 PM
Member
Thread Starter
Join Date: May 2016
Location: USA
Posts: 7
Received 0 Votes on 0 Posts
Unlikely to be welding since it occur every day, and usually late at night.

Solar power is a really interesting thought, though. There are many solar power systems in our neighborhood - they are popular right now, so more are added every year. It's definitely possible and something to look into. If one was installed within the last several months, that would be the place to start, although I suppose an older system could be failing.

Thanks
Tony
 
  #7  
Old 05-06-16, 04:36 PM
Member
Thread Starter
Join Date: May 2016
Location: USA
Posts: 7
Received 0 Votes on 0 Posts
I have an inexpessive meter that I've used during the events. It does not record any voltage issues (hot to neutral). The voltage in our area runs a little high (closer to 125V), but it's unchanged when the problem occurs. When I bought the meter, I was hoping that it would show a voltage issue. No such luck, yet.

-Tony
 
  #8  
Old 05-06-16, 04:41 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,219
Received 477 Votes on 447 Posts
The solar system invertor would be sleeping at night.... that would probably not be your issue.

Do you know how your service is grounded ?

Actual metal city water line ?
Any ground rods outside ?
 
  #9  
Old 05-06-16, 04:46 PM
Member
Join Date: Mar 2010
Location: USA
Posts: 3,683
Received 30 Votes on 29 Posts
Have you measured the (hot to neutral) voltage at different receptacles (outlets) at different times? Has the voltage changed at any test location when an event happens and buzzing is heard there or elsewhere in the house?
 

Last edited by AllanJ; 05-06-16 at 05:23 PM.
  #10  
Old 05-06-16, 04:47 PM
Member
Thread Starter
Join Date: May 2016
Location: USA
Posts: 7
Received 0 Votes on 0 Posts
Yes, we have have a ground rod at the main panel and the panel itself is relatively new (8 years old), installed just before we moved into the home. The ground rod is connected properly to the main panel. The ground was added long after the home was constructed (1960), so it's possible that cable and telephone aren't properly grounded to it... probable, even. The cable coax line does run through a surge protector that is grounded through the electrical system, however.
 
  #11  
Old 05-06-16, 04:58 PM
Member
Thread Starter
Join Date: May 2016
Location: USA
Posts: 7
Received 0 Votes on 0 Posts
I've checked some outlets, but not all. That is something I will try tonight to see if some outlets behave differently than the ones I've tested (which have showed no change in voltage during the buzzing). Thank you!

-Tony
 
  #12  
Old 05-06-16, 05:18 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,219
Received 477 Votes on 447 Posts
Can we assume... no city water or not a metal supply pipe ?
 
  #13  
Old 05-06-16, 05:39 PM
Member
Join Date: Mar 2010
Location: USA
Posts: 3,683
Received 30 Votes on 29 Posts
Is there anything which if unplugged or unhooked or unscrewed will stop the buzzing? Including the cable TV cable.

What pitch is the buzz? Is there an accompanying hum or a squeal or a whistle?
 
  #14  
Old 05-06-16, 05:40 PM
Member
Thread Starter
Join Date: May 2016
Location: USA
Posts: 7
Received 0 Votes on 0 Posts
We are on City water. The supply pipe to the house is metal. It is connected to the system ground where is enters the house (which is right next to the main panel).

-Tony
 
  #15  
Old 05-06-16, 05:45 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,219
Received 477 Votes on 447 Posts
Thanks for the reply. I have seen issues.... and quite recently.... where the power company lost the ground to their transformer and was relying on the customers house to supply it.
 
  #16  
Old 05-07-16, 07:04 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 10,230
Received 39 Votes on 31 Posts
I have seen issues.... and quite recently.... where the power company lost the ground to their transformer and was relying on the customers house to supply it.
I have seen many times where someone would steal the copper ground wire on the pole from the transformer, but don't recall seeing any issues at the customer's homes.
 
  #17  
Old 05-07-16, 08:44 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,219
Received 477 Votes on 447 Posts
Joe... at one friends house (union electrician) he was replacing the service. He pulled the meter. When he opened the neutral connection he got the shock of his life when he got a big arc. The ground to the pole was missing AND his neighbor across the street did not have any ground connected. It was all coming from his house. What a mess that was.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: