BX Questions

Reply

  #1  
Old 04-19-05, 03:56 AM
Member
Thread Starter
Join Date: Feb 2005
Location: USA
Posts: 339
BX Questions

I have home built in '29 that has some of the original BX in use. It's a little scarey to read some of the posts that use terms like "filaments" and "toaster elements" and the like. I understand when using the metal sheath for grounding that the grounding reliability depends on the mechanical connection, and I also can relate to the aging issues with the insulation.

I am not having any problems with my system, but I am not sure what all the safety issues are. I am guessing that a poor ground connection along with a ground fault would cause a problem.

What is recommended to improve the safety aspects of BX? Is it a matter of installing GFI breakers or outlets? Anything else?
 
Sponsored Links
  #2  
Old 04-19-05, 03:29 PM
scott e.'s Avatar
Member
Join Date: Jun 2003
Location: Anderson, IN
Posts: 412
If your house was built in 29 with BX (like mine) you probably don't have any legaly grounded receptacles. Therefore, there is a good chance that you don't have to worry about the sheath continuity back to the breaker panel. As for protection, you might want to put the old BX runs on arc fault breakers. I will let the others chime in on this suggestion.
 
  #3  
Old 04-20-05, 02:30 AM
Member
Thread Starter
Join Date: Feb 2005
Location: USA
Posts: 339
I do have receptacles that are grounded through the sheath.
 
  #4  
Old 04-20-05, 05:07 AM
HandyRon's Avatar
Member
Join Date: Dec 2001
Location: New York
Posts: 1,365
We've had many discussions about whether older BX (armored cable [AC cable] without an internal bonding strip) can be used as an equipment grounding conductor. I don't think all have agreed. I think old type AC cable without a bonding strip cannot be used as an equipment grounding conductor, thus you shouldn't have any three prong receptacles in your home unless you have GFCI protection and the receptacles are labeled "no ground".
 
  #5  
Old 04-20-05, 09:33 AM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
Very simple experiment--- connect a lenth of armor from "old" Armored Cable to a lenth of "Bonding" strip extracted from "new" Armored Cable and then conduct the hi-amp output from a welder thru the 2 "conductors"---- Needless to say the the Bonding strip will fuse far,far sooner than the "old" armor.

Conclusion - the "Old" armor will conduct a much higher current than the Bonding-strip.It's presence in "new" Armored Cable is NOT to conduct a Fault-Current. This is explictly stated in the book "Electrical Grounding" (R.Riley)

If the "Construcion" requirements of the 2005 Code are to be applied "retroactively", then the Type "R" conductors in the "old" Armored Cable would be rejected, Type "R" no longer an accepted type of conductor insulation..

Good Luck & Enjoy the Experience!!!!!!!!!!!!!!
 
  #6  
Old 04-20-05, 11:08 AM
Member
Thread Starter
Join Date: Feb 2005
Location: USA
Posts: 339
Originally Posted by scott e.
As for protection, you might want to put the old BX runs on arc fault breakers.
I thought arc fault breakers were for frayed cords, etc (not ground faults) Maybe you meant ground fault breakers.
 
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
'