ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
sparky 4
Recent Posts
Dimmable LED 2x4 lay in fixtures
by gfretwell. 12/13/17 09:49 PM
2017 NEC Changes
by sparky. 12/13/17 06:57 PM
Casino Wiring methods
by HotLine1. 12/09/17 10:44 AM
Ground wire Size to water Line.
by HotLine1. 12/05/17 12:11 PM
Flexible conduit to an outside Spa
by gfretwell. 12/05/17 12:28 AM
New in the Gallery:
Gallery Test
Popular Topics(Views)
243,042 Are you busy
179,475 Re: Forum
170,401 Need opinion
Who's Online Now
0 registered members (), 25 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 3 1 2 3
#168861 - 09/18/07 04:16 PM Apprentice Electrician Need help  
Chris21  Offline
New Member
Joined: Sep 2007
Posts: 5
I am an apprentice electrician. I only have 1 1/2 years experience in new residential contruction. I live with my parents. They have a problem. Lights flicker and sometimes power is lost to some things but not others. No circuit breakers are ever tripped. The power comes on to whatever is affected usually within 10-15 minutes. More than one circuit is affected by this. I replaced their old Zinsco circuit breaker box because I've read that this could be a source of the problem and sice I've read where they are a fire hazard anyway so I thought it would be the first place to start. Although the house is old and has the main breaker located outside the house. I did not replace that. Any ideas where to start? Undervoltage problem from the power company?

Work Gear for Electricians and the Trades

#168862 - 09/18/07 04:22 PM Re: Apprentice Electrician Need help [Re: Chris21]  
Tiger  Offline
Joined: May 2005
Posts: 706
Crystal Lake, IL USA
As you've replaced the distribution panel, the next guess would be the main, or the utility transformer connections. It helps if you can get a meter on it when it happens.


#168866 - 09/18/07 06:31 PM Re: Apprentice Electrician Need help [Re: Tiger]  
JoeTestingEngr  Offline
Joined: Nov 2005
Posts: 791
Chicago, Il.
Do you happen to have a couple 120VAC and 1, 240VAC cube relays lying around? You could hook the coils L1-N, L2-N, & L1-L2, via the 'a' contacts. Use #12 and wire on the load side of breakers for safety. Jumper the 'a' contact of each relay to seal it in and walk away. Indicating relays would add style points. Losing a 120VAC and the 240VAC relay means your losing a leg. Just a 120 relay dropping would clue you in to the nasty floating neutral.

#168869 - 09/18/07 08:53 PM Re: Apprentice Electrician Need help [Re: Chris21]  
Niko  Offline
Joined: Aug 2006
Posts: 356
Campbell, CA

Sinec you have flickering i would say there is a loose connection on that circuit. You need to take out all of the devices from the each box and check the connections. I bet you that one of the connections is burnt or almost there.

Loose connection.

It is good that you have replaced the ZINSCO, but for future i would not start out by replacing the panel.

Be kind to your neighbor, he knows where you live

#168873 - 09/18/07 09:04 PM Re: Apprentice Electrician Need help [Re: Niko]  
ShockMe77  Offline
Joined: Jun 2005
Posts: 821
Rahway, New Jersey
I would start by checking your voltage at the panel. Check one leg to ground (120), then the other to ground (120), and finally both to each other (240). Then check each individual circuit breaker. If all that checks out, then I would locate the branch circuit that's giving u the problem and shut that breaker off. Only then would I start removing devices to check for good terminations. Probably a stab-lock somewhere, lol.

#168874 - 09/18/07 09:07 PM Re: Apprentice Electrician Need help [Re: Niko]  
Chris21  Offline
New Member
Joined: Sep 2007
Posts: 5
Thanks Tiger, joe, niko.

Niko, I have intermittent flickering lights and loss of power on more than one circuit. Replacing the box was something I wanted to do anyway so I figured I would start there.

Any other thoughts anyone?

#168893 - 09/19/07 11:49 AM Re: Apprentice Electrician Need help [Re: Chris21]  
gibbonsseabee80  Offline
Joined: Oct 2005
Posts: 40
Chesapeake, VA
Hello Chris,
I would borrow a multi-meter from someone at work and take some voltage readings. If the lights flicker so often, wait around for it to go crazy and take some meter readings. Since you said the problem is on multiple circuits, I would pull the cover off the outside main and meter pan. Check for water damage or corrosion on the equipment. Sometimes water gets into old services and makes a muck of everything. And last, make sure you have a good nuetral and that you have good ground connections, via the electrode and water main. You could have a bad nuetral somewhere. These are just a fews things you can check. Some of the guys will have some other good recommendations also.


Brian Gibbons

#168894 - 09/19/07 12:33 PM Re: Apprentice Electrician Need help [Re: gibbonsseabee80]  
JValdes  Offline
Joined: Jun 2007
Posts: 301
South Carolina
Multiple circuits indicate to me that it is a main power supply issue. Service, Main Panel or Sub panel if present.

I had a customer some years ago with the same issue. After several visits I had no idea what the problem was.
The customer made a comment that "it seems to happen on windy days".
So I went back and visually inspected the incoming power from the service all the way back to the transformer. While standing under the XFMR I heard a cracking sound. (electrical) short.
Called POCO and they found that the service wires on the secondary had worn enough for them to short to each other intermitantley.

Moral of the story. "It's not always your problem, it could be theirs"

If the customer would not have mentioned windy days, this would still be happening. Go outside and have a good look around. But don't touch anything you are not trained to work on......Good Luck

Last edited by JValdes; 09/19/07 12:34 PM. Reason: spelling

#168895 - 09/19/07 12:41 PM Re: Apprentice Electrician Need help [Re: JValdes]  
Zog  Offline
Joined: Sep 2005
Posts: 120
Charlotte, NC
Maybe your parents are screwing with you :-)

MV/HV Testing Specialist, "BKRMAN"

#168896 - 09/19/07 01:41 PM Re: Apprentice Electrician Need help [Re: Zog]  
Niko  Offline
Joined: Aug 2006
Posts: 356
Campbell, CA
Are you sure they are physicaly on two different circuits?

I just want to make sure, because some people call receptacles and lighting two different circuits even though they are one.

I just want to make sure that we all are on the same page.

If you can get a hold of a meter that has recording capability. (Max, Min, Average) hook it up at the suspect circuit, turn on a resistive load (hair dryer) inside the house and see the voltage reading on the meter. If you have a large voltage drop at the output of breaker then move the meter to the bus bar, if you still have large voltage drop then call POCO.

Now, if you don't have large voltage drop at the breaker but have flickering lights inside the house (with your hair dryer on) then the problem is inside.

I am suggesting a hair dryer because it is large load and you want to put some strain on that circuit in order to create loose connection or flickering effect on that circuit.

Be kind to your neighbor, he knows where you live

Page 1 of 3 1 2 3

Member Spotlight
Posts: 165
Joined: March 2007
Show All Member Profiles 

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.016s Queries: 16 (0.003s) Memory: 0.8225 MB (Peak: 1.0023 MB) Zlib enabled. Server Time: 2017-12-14 17:02:27 UTC