Circuit breaker spark

Reply

  #1  
Old 01-29-18, 01:14 PM
Sunburn's Avatar
Member
Thread Starter
Join Date: Oct 2017
Location: United States
Posts: 46
Received 0 Votes on 0 Posts
Circuit breaker spark

I had a circuit in the off position because it goes outside but isn't in any conduit, I was going to put it in conduit later this year for protection (the wire is for outdoor use). While I was redoing my panel, I moved it up two positions for better wire organization in the panel (the electrical panel and circuit breaker were off during this). Today with my volt detector I noticed the line was hot, but the circuit breaker was off. I took the electrical panel cover off to confirm the wiring was correct, it was. I flipped the circuit to on and a spark came out of breaker and went to middle position. I have moved it to off and confirmed the cable is not hot, there's nothing on this circuit but 1 light and four outlets (only one is GFCI'd).

1. Why was the breaker off, but the wire was hot?
2. Why did it spark?
3. Now what do I do?
 
Sponsored Links
  #2  
Old 01-29-18, 02:46 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 58,569
Received 1,041 Votes on 965 Posts
When you do wiring wiring work you really need a voltmeter. Even a basic analog from the home improvement stores is ok.

When two wires run next to each other..... one live and one dead.... you can detect power on the dead one just because it's near the live one. The magnetic fields couple the two wires together. It's called a ghost or induced voltage as it really isn't harmful.

When you turned the breaker on it tripped due to a short. That's where the spark came from. You will need to determine what is causing the short on that circuit. It could be a receptacle hitting ground or something similar. Here would be a good application for your analog meter to check for a short.
 
  #3  
Old 01-29-18, 06:37 PM
Sunburn's Avatar
Member
Thread Starter
Join Date: Oct 2017
Location: United States
Posts: 46
Received 0 Votes on 0 Posts
I'm thinking you're right about the magnetic field. I capped off the hot and neutral in the j box and turned off the breaker, then confirmed it was not hot with the volt detector. After a few hours, I checked the wire with the volt detector and it was hot again. Is there a wire rating that prevents this?
 
  #4  
Old 01-29-18, 06:43 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,144
Received 84 Votes on 72 Posts
It is a characteristic of a non-contact voltage detector. A nearby magnetic field can be picked up making the wire look hot.
 
  #5  
Old 01-29-18, 07:02 PM
Sunburn's Avatar
Member
Thread Starter
Join Date: Oct 2017
Location: United States
Posts: 46
Received 0 Votes on 0 Posts
Well that's a relief, I've been reading up on volt detectors and see where it affects the readings. Could the induced voltage also have caused the spark when I switched the circuit breaker from off to on?
 
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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: