ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Light activation in closet by a broken connection?
by geoff in UK. 02/19/19 01:35 PM
AFDD's coming to the UK
by Texas_Ranger. 02/18/19 02:04 PM
by Texas_Ranger. 02/18/19 02:01 PM
by gfretwell. 02/16/19 01:08 PM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
1 registered members (Scott35), 12 guests, and 20 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Re-posting high and low voltage problems #68643
08/11/06 10:03 PM
08/11/06 10:03 PM
billy6139  Offline OP
Joined: Mar 2006
Posts: 8
Carson,Ca. USA
Reposting because topic was lost. I received one answer from Roger.

Scenario:Mobilehome park with 192 units. Main distribution is 240/120 3 wire from Edison. All main feeders are 100A 2 pole breakers feeding 4 to 8 pedestals with 50A mains. All distribution wiring is direct burial 1/0 aluminum, no conduits.
Problem: flucuating voltage. When loads are present(at times) voltage (between neutral or ground) on 1 leg lowers to 90 vbolts, while the other side increases to 140 volts. Voltage line to line is approximately 245 volts and fairly steady. This problem exist about 4 to 5 hundred feet away from main distrubution panel where voltage on the losd side of the breakers(at main distribution panel) remains 240/122, steady as a rock.
Has anyone ever experienced this? Any solutions?

Work Gear for Electricians and the Trades
Re: Re-posting high and low voltage problems #68644
08/12/06 01:15 AM
08/12/06 01:15 AM
Larry Fine  Offline
Joined: Feb 2005
Posts: 693
Richmond, VA
This is definitely an open neutral problem. The normally-zero-volts-to-ground on the neutral is being forced away from zero due to normal neutral current.

It can be a hazard because what should be grounded surfaces are instead being fed by the 25-or-so volts, and must be repaired ASAP.

Troubleshooting this would start with isolating the section with the broken line by finding the last point where the problem doesn't exist and the first point where it does.

Then start digging.

Larry Fine
Fine Electric Co.
Re: Re-posting high and low voltage problems #68645
08/12/06 10:09 AM
08/12/06 10:09 AM
e57  Offline
Joined: May 2003
Posts: 2,876
I had the EXACT SAME PROBLEM, AND SCENARIO ten or so years ago.

I used to service work and had this, in a trailer park in Concord CA. Turned out to be a U/G direct burial feeder had a nick, and the AL conductor rotted over time.

To save on digging, put a tracer on the neutral and hope you get a dead end to the signal from both sides near the same spot. If you do thats were the Christy box goes. Becacuse it is intermitant they is no real guarantee it will would but well worth the shot!

Another method is to TDR the run, or use a pulse generator on the run. If you dont have any of the varied expensive equipment to find it, there are companies that specialize in it that you can sub it out too. Or you can rent it...

Mark Heller
"Well - I oughta....." -Jackie Gleason


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


Member Spotlight
Portland, Oregon, United States
Posts: 404
Joined: March 2007
Show All Member Profiles 
Top Posters(30 Days)
Admin 9
Popular Topics(Views)
253,292 Are you busy
189,905 Re: Forum
179,625 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.023s Queries: 14 (0.005s) Memory: 0.9525 MB (Peak: 1.0758 MB) Zlib enabled. Server Time: 2019-02-22 02:47:57 UTC