Electrical Problem - Electrical - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools
Display Modes
Old 05-31-2010, 09:17 PM   #1
Newbie
 
Join Date: May 2010
Location: Smithsburg,MD
Posts: 4
Rewards Points: 10
Default

Electrical problem


I have 240 volts to ground on one phase and 60V on the other phase in a 120/240V single phase system. This happens when I turn all lights on from one location and flip the swithes in other location which one light dims to almost off while another light gets brighter and another light just goes off. The 3-ways are wired correctly and so on.What can cause this goofy situation? I am thinking its gotta be the service cable coming in.Broken wires including the neutral but still nothing is tripping.So how is this possible ??????
Bob B is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-31-2010, 09:21 PM   #2
Member
 
Join Date: Jul 2008
Location: NW of D.C.
Posts: 5,990
Rewards Points: 2,000
Default


Quote:
Originally Posted by Bob B View Post
I have 240 volts to ground on one phase and 60V on the other phase in a 120/240V single phase system.
So how is this possible ??????
It shouldn't be.
Both phases have to add to 240v so with a bad neutral connection you could have 100v and 140v or some other combination, like 80v/160v.

For the 100/140 combo the neutral connection has (140-100)/2 = 20v across it, instead of 'zero.' Then, if one phase was pulling 10A and the other was pulling 8A, there would be 2A flowing through the neutral, with a power dissipation of 2A(20v) = 40w which make for a pretty hot connection.

You are shortening the life of everything that is running on the higher voltage.

Last edited by Yoyizit; 05-31-2010 at 09:26 PM.
Yoyizit is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-31-2010, 09:49 PM   #3
Newbie
 
Join Date: May 2010
Location: Smithsburg,MD
Posts: 4
Rewards Points: 10
Default


Quote:
Originally Posted by Yoyizit View Post
It shouldn't be.
Both phases have to add to 240v so with a bad neutral connection you could have 100v and 140v or some other combination, like 80v/160v.

For the 100/140 combo the neutral connection has (140-100)/2 = 20v across it, instead of 'zero.' Then, if one phase was pulling 10A and the other was pulling 8A, there would be 2A flowing through the neutral, with a power dissipation of 2A(20v) = 40w which make for a pretty hot connection.

You are shortening the life of everything that is running on the higher voltage.
TY for responding. I understand what you said but why is this happening?
Bob B is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-31-2010, 09:56 PM   #4
Newbie
 
Join Date: May 2010
Location: Smithsburg,MD
Posts: 4
Rewards Points: 10
Default


Quote:
Originally Posted by Bob B View Post
TY for responding. I understand what you said but why is this happening?
I did turn their main off and feeding this particular apt with the house panel . All lighting works normal.Temp only until I change the SEC.
Bob B is offline   Reply With Quote
Old 05-31-2010, 10:00 PM   #5
Member
 
Join Date: May 2010
Posts: 31
Rewards Points: 25
Default


You most likely have a loose neutral wire either at your panel, the meter/disconnect, or at the utility transformer. The term is called floating neutral as it's not pegged between the 2 phases and floats to wherever the current is pulling it.
fpeftw is offline   Reply With Quote
The Following User Says Thank You to fpeftw For This Useful Post:
Bob B (05-31-2010)
Old 05-31-2010, 10:07 PM   #6
MXer
 
3 legged dog's Avatar
 
Join Date: Dec 2009
Location: South West Coast
Posts: 128
Rewards Points: 75
Default


did you mean 240 volt to neutral? If so it is a bad neutral somewhere. If You get 240 volt to ground than you got bigger problem.
3 legged dog is offline   Reply With Quote
Old 05-31-2010, 10:08 PM   #7
Super Moderator
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 18,853
Rewards Points: 24,048
Blog Entries: 11
Default


You have a loose or open neutral. The voltage is not being split equally between the two hots. Everything is in series and some devices are getting low voltage while others are getting high voltage. Turn off the power until you get this serviced. The voltage can cause severe damage to your electronic devices.
joed is online now   Reply With Quote
The Following User Says Thank You to joed For This Useful Post:
Bob B (05-31-2010)
Old 05-31-2010, 10:15 PM   #8
Newbie
 
Join Date: May 2010
Location: Smithsburg,MD
Posts: 4
Rewards Points: 10
Default


Quote:
Originally Posted by 3 legged dog View Post
did you mean 240 volt to neutral? If so it is a bad neutral somewhere. If You get 240 volt to ground than you got bigger problem.

most definitly..so its gotta be in the service cable>I'm fixing this prob tomorrow.THX
Bob B is offline   Reply With Quote
Old 06-01-2010, 12:29 AM   #9
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Rewards Points: 2,000
Default


Quote:
Originally Posted by Bob B View Post
I did turn their main off and feeding this particular apt with the house panel . All lighting works normal.Temp only until I change the SEC.
Something got my attetion the word apt { apartment } do you own and live in this building ? if not you must get the electrician to come out and deal with it.

The service entrance cable are you using 3 or 4 conductor format if use 4 make sure you land it in proper location you can not get the netural and ground mix up in subpanel location this is circital.

Merci,Marc
frenchelectrican is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to install new electrical box without attic access gilmores33 Electrical 10 02-14-2010 07:46 PM
Slight electrical current in bathroom faucet water + other unusual electrical events story Electrical 9 09-16-2009 10:28 PM
Electrical receptacle problem centralhome Electrical 13 12-27-2008 01:45 PM
Electrical "arcing" problem? morden5b Electrical 17 12-17-2008 06:10 PM
Post-Tension Slab Problem Advice/Help Mike McBride Building & Construction 2 01-09-2007 01:51 PM




Top of Page | View New Posts