Electrical Wiring in the Home/Lights flicker


QUESTION: Hello Robert!  I had my kitchen remodeled.  New lighting was installed in the ceiling. As the project was nearing completion, we noticed that the lights throughout the entire house would flicker for a second when the refrigerator compressor would come on.  Same thing with the microwave, same with the dehumidifier, and when the washer is running, the lights throughout the whole house flicker in time with the agitator going back and forth, like a strobe effect! We pointed this out to the contractor and he had his electricians review their wiring and said nothing was wrong and that they had never seen anything like this.  They were hoping that it had been that way before they started.  Wrong!  Of course the ceiling had been redone so they could see up in the ceiling where they installed the can lights.  He said that perhaps it was a problem with the transformer out on the street and to call the electric utility to check it, but before we could do that the problem mysteriously disappeared, so we paid the contractor and thought we were all set.  3 months later, the issue is back, same as before.
I have some basic electrical knowledge, I own a volt-ohm meter and can measure continuity, voltage, etc.  I have replaced a breaker in my electrical box before, but I have no idea where to start in trying to figure this problem out.  Since the problem effects all of the lights throughout the whole house, it's like the house is on one big individual circuit instead of separate circuits.  Any ideas on what could be happening?  I'm tired of living in the disco with flickering lights!  Thank you.

ANSWER: I wouldn't have paid til the problem was resolved.
I would have said it was up to them to prove they didn't cause the problem, and agreed to pay extra if they proved it was not them and fixed it.

...then again, it is likely not anything from the kitchen
sounds like a neutral issue-maybe an open neutral or loose termination-Panel issue, they were in the panel and touched terminations and wiring
it is important to know which circuit the problems are on, bus-bar balancing, etc.
Have the utility check integrity of feed to house, including neutral terminations.

after that:

record voltages between circuit "hot" and neutral at various locations

map house, outlets and circuits

Are you qualified to open main panel and test circuit voltages?

National Electrical Code definition, NFPA 70 2008 Article 100: Qualified Person. "One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved."

If not, find someone qualified who has a better answer than "It wasn't me!"
Have your candidate call me -  610-299-0452 - if you like and he is willing, or you can call...

Got an electric range - Does problem diminish if you turn burners on? or electric dryer?

---------- FOLLOW-UP ----------

QUESTION: Thank you Robert!  This was exactly what I was hoping for, a game plan for getting this fixed.  I wasn't going to pay them until it was fixed, but the problem went away so I couldn't really not pay when everything was working fine.  That was what was so puzzling, I had them scratching their heads searching for an answer and then the issue just disappeared.  Three months later, it starts up again.

Yes, they were in the panel.  We had the old electric range replaced with an electric cooktop and electric oven, two separate appliances.  They were going to try and use the old panel, but it didn't have enough space for 2) 220v appliances, so they installed a small panel next to the old one and put those two appliances in that box.  So to answer your question about the problem diminishing if the stove is on, the answer is that there is no flickering if I use the stove or oven.  But if I turn on the microwave right above it, or the garbage disposal, or the refrigerator compressor kicks on, the lights all over the house flicker or dim.  But all of these appliances are on the old box.  Does that strengthen your thought that there is probably a neutral connection problem in the old box?

I'll contact the utility and have them check the feed to the house, including neutral terminations.  And I'll map the breakers through the house and record voltages on each circuit.  The panel work I'm going to contract out.  I know a retired licensed electrician and so I'll see if he is interested in some work.

One other question regarding troubleshooting this issue.  Would it be helpful if I shut down each circuit breaker one by one and turned on an appliance to see if there is flickering to see if I can isolate a particular circuit?

Thank you again for your help, I am very grateful!

So because there are only 240 volt loads in the subpanel, you don't know that the same problem doesn't exist there as well.
What I was asking was if the problem diminishes if you turn on the 240 volt loads. That would support the neutral issue theory.
Also map voltages under changing load conditions, like kitchen counter receptacle to left of refrigerator is on circuit 3 and is 118 volts with microwave off and 87 volts with microwave on and 107 with microwave and stove on.
Get the drift? Maybe a spreadsheet would help with the record.
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Electrical Wiring in the Home

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Robert Wilber


Licensed Philadelphia electrician serving Delaware, Chester, Montgomery and Philadelphia County in Pennsylvania. I install and repair residential, commercial and industrial wiring and lighting. Troubleshooting and repair of problems that stump other people is my favorite. I am willing to help people figure out why things don`t work. I understand motor controls, transformers and machine wiring. I do not teach basics to novices or do free design work.


Experience in the area I have 44 years experience in residential, commercial and industrial electrical construction and repair, 480 volts and below. This is not to be confused with one week repeated two thousand times.

44 years experience in residential, commercial and industrial electrical construction and repair

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