ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
twh 3
Recent Posts
FPE in Germany
by Texas_Ranger. 11/19/17 07:30 AM
Ceiling fan distance from outdoor hot tub
by gfretwell. 11/16/17 02:18 AM
diazed fuses
by Texas_Ranger. 11/13/17 03:02 PM
Theft deterrent alarm
by gfretwell. 11/12/17 01:39 PM
EEPROM errors on XC7Z010-2CLG225I chip
by twh. 11/07/17 05:45 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
242,601 Are you busy
178,782 Re: Forum
170,037 Need opinion
Who's Online Now
0 registered members (), 16 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#185812 - 03/29/09 04:44 PM Brittle THHN insulation on NM-B conductors  
newsgraphics  Offline
Member
Joined: Nov 2005
Posts: 11
California
Last night I was installing a ceiling fan in our relatively new house (built in 2005). It was pre-wired for ceiling fans, so this should have been an easy installation. However, after twisting the wire nut onto two of the conductors, I noticed that the insulation on the THHN jacket had literally split and exposed the bare copper wire!

Admittedly, I did crank those wire nuts on tightly, but I have never had a problem with insulation splitting like this before. I ended up having to cut it back about two inches. Has anyone else had this occur before?


2017 / 2014 NEC & Related Books and Study Guides

#185813 - 03/29/09 05:17 PM Re: Brittle THHN insulation on NM-B conductors [Re: newsgraphics]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,135
Estero,Fl,usa
I have seen a lot of the teflon jacket splitting off but the thermoplastic insulation always seems OK.


Greg Fretwell

#185814 - 03/29/09 05:19 PM Re: Brittle THHN insulation on NM-B conductors [Re: gfretwell]  
newsgraphics  Offline
Member
Joined: Nov 2005
Posts: 11
California
Must have been Chinese made wire or something!


#185817 - 03/29/09 09:14 PM Re: Brittle THHN insulation on NM-B conductors [Re: newsgraphics]  
KJay  Offline
Member
Joined: Nov 2007
Posts: 763
MA, USA
Just wondering, did you remove the NM outer jacket with a utility razor knife or maybe use those Klein NM cable stripping pliers?
I've often seen the type of problem you described when these tools are used.


#185820 - 03/30/09 02:15 AM Re: Brittle THHN insulation on NM-B conductors [Re: KJay]  
newsgraphics  Offline
Member
Joined: Nov 2005
Posts: 11
California
Hard to say what kind of tool was used by the original installers, this is a tract home, but your suspicions sound quite plausible.



Member Spotlight
NickD
NickD
Amish Country, PA
Posts: 46
Joined: March 2013
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.015s Queries: 15 (0.003s) Memory: 0.7676 MB (Peak: 0.9068 MB) Zlib enabled. Server Time: 2017-11-21 11:59:22 UTC