Disposal causes surge in lighting

Reply

  #1  
Old 09-05-17, 11:02 AM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
Disposal causes surge in lighting

When I turn on the sink disposal there is a surge in some of the lighting around the house., several circuits, but not all of them. I had heard it could be from a loose ground or a loose neutral wire. I had the power off so I tightened all of the ground connectors and all of the neutral connectors. It seems like some of the surging stopped but I am not positive, I didn't write down all of the offending circuits.

Is the problem generally caused by loose ground or loose neutral wires?

Could the problem also be located in a multi gang box where the wires are twisted together?

If it occurs in specific circuits, is it a problem with that circuit?
 
Sponsored Links
  #2  
Old 09-05-17, 12:43 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,755
Received 346 Votes on 324 Posts
By surging.... do you mean that when the disposer is used..... some lights get brighter and not dimmer ?

It's possible that a multi wire branch circuit feeds that disposer and the lighting line. If it was a mwbc issue..... the two affected circuits would be one above the other in the panel. You could remove the panel cover to see if the two circuits are on a single three wire cable.
 
  #3  
Old 09-06-17, 06:35 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
I just was able to figure this out. They are on the same three wire cable. The breakers are not next to each other in the panel, not sure if it make a difference.

Is there anything that can be done about it?
 
  #4  
Old 09-06-17, 06:42 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,755
Received 346 Votes on 324 Posts
The circuits need to be on opposite legs of the 240v power so that each one shares the neutral equally. It's customary to have the breakers one over the top of the other. Now...by code..... the handles must be interlocked so that both circuits are de-energized at the same time.

You can probably move circuits/breakers around. A picture of the panel with the cover off will give us something to go by.

http://www.doityourself.com/forum/el...-pictures.html
 
  #5  
Old 09-06-17, 06:50 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
I will submit a picture tomorrow when I go back out there and there is more light. If the breakers are separated by a single breaker then they are on the same leg. An easy check is to move them next to each other so they are on different legs
 
  #6  
Old 09-06-17, 07:07 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,755
Received 346 Votes on 324 Posts
Every row is on an opposite leg.

1-A.......2-A
3-B.......4-B
5-A.......6-A
7-B.......8-B
9-A.......10-A
11-B.....12-B
etc.
 
  #7  
Old 09-06-17, 07:58 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,923
Received 24 Votes on 20 Posts
A motor load would typically cause a sag in voltage, not a surge. Is only one circuit affected or is this throughout the whole house?
 
  #8  
Old 09-10-17, 09:42 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,989
Received 22 Votes on 17 Posts
When I turn on the sink disposal there is a surge in some of the lighting around the house., several circuits, but not all of them.



How do you know you are getting a surge? What instrument have you used to determine a surge?
 
  #9  
Old 09-10-17, 10:57 AM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
@CasualJoe: I can visually see the light get brighter momentarily.
 
  #10  
Old 09-11-17, 09:16 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,989
Received 22 Votes on 17 Posts
@CasualJoe: I can visually see the light get brighter momentarily.

Ok, so we finally confirmed something. The voltage isn't sagging, but this doesn't sounds like a surge either, but a momentary increase in voltage. Sounds as if you could have a poor or weak neutral connection on a multiwire branch circuit.
 
  #11  
Old 09-11-17, 11:00 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,755
Received 346 Votes on 324 Posts
Did you take any pictures yet ?
 
  #12  
Old 09-13-17, 05:15 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
I may have been wrong, who knows. I switched the wires going to the breaker that shared a wire with the disposal circuit and it doesn't happen any more.

What happens now is that when the disposal is turned off some of the lights in the house flicker. This has been a problem for a while, I was told a long time ago by an electrician this can be, I forgot if he said ground or neutral wire loose.

Is there a way to solve this problem? Or at least know what the issue is.

Thanks for all of your guidance.
 
  #13  
Old 09-13-17, 05:37 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
I didn't take any, it is a huge jumble mess of wires. It is hard to tell anything without moving wires around. We have a gas powered generator and a transfer box that gives us power when we get a large storm and a tree falls on the power lines in the neighborhood.
 
  #14  
Old 09-13-17, 05:42 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,755
Received 346 Votes on 324 Posts
We were trying to confirm a multi wire branch circuit.
You moved wires around.... ok. Not really telling us much though.

A loose ground will not cause any dimming or flickering.
A loose neutral or hot can cause your problem.

We can only guess where the problem is. The lights flickering when you turn the disposer off is pretty strange and doesn't make much sense. Previously they were getting brighter when you started the disposer..... that made more sense.
 
  #15  
Old 09-14-17, 06:36 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
I found that the cable that was controlled by the disposal circuit was a 12-3 cable and the other conductor was inserted in the breaker two past the disposal breaker. They are all 15 amp breakers so I just switched the two next conductors so the disposal and the other conductor that share the neutral are in subsequent breakers, on different legs in the panel. The surge/spike no longer happens.

There is also a problem that other light circuits in the panel dim momentarily when the disposal is turned on. You said it could be a problem with a loose neutral connection so I need to try to see what that is.

I have tightened all of the neutral connectors in the main panel, they are all old so they are flat screw driver connectors. Should I change them out to square driver connectors, if I can even do that?

Is there a systematic way to find which circuit/circuits is causing the problem? I assume it could be more then one. Can I shut off a circuit breaker and it is the offending circuit, will the problem go away, or is it independent of the load?
 
  #16  
Old 09-14-17, 07:24 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
I just switched the two next conductors so the disposal and the other conductor that share the neutral are in subsequent breakers, on different legs in the panel.
You need to add a handle tie between those two breaker.
they are flat screw driver connectors. Should I change them out to square driver connectors
Flat tip is fine.
There is also a problem that other light circuits in the panel dim momentarily when the disposal is turned on.
Inrush current for a motor is three times or more running amps. I'd suspect nothing wrong. As a test plug the GD into a heavy duty extension cord plugged into another circuit.
 
  #17  
Old 09-14-17, 08:50 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
Inrush current for a motor is three times or more running amps. I'd suspect nothing wrong.
Something is not right it seems, I have not experienced this problem at other peoples houses? Is there really nothing I can do to eliminate this annoyance?
 
  #18  
Old 09-14-17, 09:58 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Test as I suggested and we can go from there.
 
  #19  
Old 09-17-17, 04:31 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
I made a box that has a receptacle and a switch that O could plug the disposal into and a long cord to another plug in the house. When I used this device and turned the disposal on there is no flicker at all.

The flicker occurs in many rooms when it does occur and with the disposal plugged into a different plug it does not happen in two rooms. I didn't check everywhere, just two rooms that I knew were issues.
 
  #20  
Old 09-17-17, 07:11 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
When I used this device and turned the disposal on there is no flicker at all.
Which pretty much rules out the disposal as the problem.

You could try a new breaker or move the existing breaker to another spot in the panel on the other leg of the panel. At this point I'd probably just run a new circuit just for the disposal if it wasn't too hard.

Of course running a new circuit doesn't solve the mystery but sometimes just eliminating the problem is quickest and hopefully a new circuit would do it but no guarantee.
 

Last edited by ray2047; 09-17-17 at 07:33 PM.
  #21  
Old 09-18-17, 10:31 PM
Member
Thread Starter
Join Date: Aug 2017
Location: USA
Posts: 28
Received 0 Votes on 0 Posts
I changed to another 15 amp breaker, no difference.
I changed to a 220 amp breaker, no change as expected.

It will be virtually impossible to run a new circuit, I will give the idea more thought. All of the wiring runs in the joists between the first and second floor. I am going to try this, I think it might have something to do with light circuits on the same leg. I will check all of the light circuits that are on that leg. Maybe if I move the non light circuits to this leg it will be less noticeable.

Is there any way to measure what is going on here?
 
  #22  
Old 09-19-17, 02:41 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
All of the wiring runs in the joists between the first and second floor
If there is no unfinished basement underneath you can run outside in conduit. Where I am and newer houses are on slabs and it is very common to run conduit around the house either buried or fastened to the wall.

You said it didn't dim the lights when you tested. Which leg was that?
 
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
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: