Drywall Screw in Wire?

Reply

  #1  
Old 12-17-07, 07:09 AM
Member
Thread Starter
Join Date: Nov 2007
Location: Canada
Posts: 44
Received 0 Votes on 0 Posts
Drywall Screw in Wire?

Hey. I noticed while drywalling my shower stall that the GFI outlet had tripped. The first thing that came to mind is that I hit a wire with a drywall screw. I have reset it and everything seems fine but I have lingering doubts. My questions are: If I did hit a wire is this a big problem? If I put a tester to all the drywall screws would I expect power to be on a drywall screw had it hit the wire? Thanks in advance. Paul
 
Sponsored Links
  #2  
Old 12-17-07, 07:42 AM
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
Received 0 Votes on 0 Posts
If you did hit the cable, it's a HUGE problem.

Theoretically, all cable should be at least 1.25" behind the stud face, or protected by a metal plate. Did you happen to notice if this was true in your case? Did you run the wiring yourself, or was this existing wiring?

Drywall screws are normally no longer than 1-5/8". Did you use screws longer than this?

There are other reasons the GFCI might have tripped.
 
  #3  
Old 12-17-07, 08:06 AM
Member
Thread Starter
Join Date: Nov 2007
Location: Canada
Posts: 44
Received 0 Votes on 0 Posts
Originally Posted by John Nelson View Post
If you did hit the cable, it's a HUGE problem.

Theoretically, all cable should be at least 1.25" behind the stud face, or protected by a metal plate. Did you happen to notice if this was true in your case? Did you run the wiring yourself, or was this existing wiring?

Drywall screws are normally no longer than 1-5/8". Did you use screws longer than this?

There are other reasons the GFCI might have tripped.
Hey John... Thanks for getting back to me. I ran some of the wire and I did centre in the stud. I used 1 5/8 screws and 1/2 drywall. By all rights I should have missed but I do remember a few screws going a tad deeper and the hole in the stud may not have been perfectly centred.

I understand that the GFI could have been set off by a number of things but I find this highly suspicious. I was wondering if there is some way to determine if in fact this happened or not besides taking the drywall off. It is a very contained area but I would have to remove 70 screws. Thx
 
  #4  
Old 12-17-07, 08:35 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
Putting a screw through cable between a GFCI and the panel would either trip the circuit breaker or would simply connect the ground and neutral. It should not effect any downstream GFCIs.

Putting a screw through the cable after a GFCI would either cause a short between hot and the neutral or the ground, or would connect the ground and neutral. The ground and neutral being shorted would cause the GFCI to trip when a load is applied. The hot being shorted to something should have tripped the breaker, although it may trip a GFCI.
 
  #5  
Old 12-17-07, 08:55 AM
Member
Thread Starter
Join Date: Nov 2007
Location: Canada
Posts: 44
Received 0 Votes on 0 Posts
Originally Posted by John Nelson View Post
If you did hit the cable, it's a HUGE problem.

Theoretically, all cable should be at least 1.25" behind the stud face, or protected by a metal plate. Did you happen to notice if this was true in your case? Did you run the wiring yourself, or was this existing wiring?

Drywall screws are normally no longer than 1-5/8". Did you use screws longer than this?

There are other reasons the GFCI might have tripped.
Originally Posted by racraft View Post
Putting a screw through cable between a GFCI and the panel would either trip the circuit breaker or would simply connect the ground and neutral. It should not effect any downstream GFCIs.

Putting a screw through the cable after a GFCI would either cause a short between hot and the neutral or the ground, or would connect the ground and neutral. The ground and neutral being shorted would cause the GFCI to trip when a load is applied. The hot being shorted to something should have tripped the breaker, although it may trip a GFCI.
Thanks! I have reset the GFI and everything seems okay. Should I be concerned?
 
  #6  
Old 12-17-07, 08:59 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
You haven't told us what type of GFCI it is or where the wire you think you may have hit is located.
 
  #7  
Old 12-17-07, 09:29 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Hey John... Thanks for getting back to me. I ran some of the wire and I did centre in the stud. I used 1 5/8 screws and 1/2 drywall.
If you know the approximate height of the cable that is connected to the GFCI (I'm presuming it's horizontal) you could carefully cut a small area of Sheetrock on either side of a stud to see if the screw lines with the cable.
 
  #8  
Old 12-17-07, 09:31 AM
Member
Thread Starter
Join Date: Nov 2007
Location: Canada
Posts: 44
Received 0 Votes on 0 Posts
It is a GFI outlet near the vanity of a small ensuite washroom. I used this receptacle based on advice in this forum to run power to a light I installed in the shower. The wire from the GFI goes into the attic and into the shower light fixture and a wire from the fixture runs behind the wall in question into a switch.
 
  #9  
Old 12-17-07, 09:36 AM
Member
Thread Starter
Join Date: Nov 2007
Location: Canada
Posts: 44
Received 0 Votes on 0 Posts
Easier just to take off the drywall sheet. I was just hoping there was some way I could take a tester to the drywall screws to see if there was power to any of them. Not sure if there would be but it sounded like a good plan. If I can't do that and I do remove the drywall, what do I do if I see that a wire was punctured? Can I just put some electrical tape around it?
 
  #10  
Old 12-17-07, 09:48 AM
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
Received 0 Votes on 0 Posts
If you see a cable that has been hit, you must remove and replace the entire length of that cable. But I suspect you won't find any damage. Removing and replacing the drywall will be good for your peace of mind. While you're in there, measure the distance from the face of the stud to the edge of the each hole. If any are less than 1.25" put a protector plate over it before rehanging the drywall. And then make sure your drywall screws don't break the face paper of the drywall.
 
  #11  
Old 12-17-07, 09:54 AM
Member
Join Date: Nov 2007
Posts: 160
Received 0 Votes on 0 Posts
you could turn the power off then run a jumper wire from the wires (one at a time) on the gfci then use ohms on the meter and touch one lead to the screw the other to the jumper wire. If it rings out on any of the three wires then you know the screw is touching that wire.

My thought would be I don't think that you hit anything if it didn't trip the branch circuit breaker
 
  #12  
Old 12-17-07, 09:59 AM
Member
Thread Starter
Join Date: Nov 2007
Location: Canada
Posts: 44
Received 0 Votes on 0 Posts
thanks to everyone. I will go for peace of mind. Thx again!
 
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: