xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
Can someone explain why the exception to 500.8E1 exists? I am just looking to understand the exception better.
500.8 exception
- Thread starter xformer
- Start date
- Status
Please be more specific... there is no 500.8 Exception No. 1. The only exceptions are:
500.8(C)(3) Exception
500.8(C)(4) Exception
500.8(E)(1) Exception
xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
Sorry, I was looking at 500.8 (E) (1) Exception and the reasoning behind it.
IDK. Now I'm curious too! :blink:
xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
Me too. My understanding is that for conduit and coupling connections its 5 full threads. But conduit to devices housings it 4 and 1/2? Don't couplings come with manufactured threads also?
The exception is regarding listed explosionproof equipment. While threaded couplings are permitted for hazardous-location wiring methods, I don't believe they are listed as explosionproof equipment.
Just a guess, but perhaps 4-1/2 threads for listed explosionproof equipment is to permit tapping the wall anywhere... and the wall is not thick enough to permit a full 5 threads of engagement...???
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
I have been avoiding this since I don't agree with the Exception.. The original Proposal suggested only 3-1/2 threads engaged.
The history is in the 2005 cycle ROP/ROC. Check the "Current & Prior Editions" tab and then the 2005 drop menu, then the "Read the archived revision information" link, From there you're on your own.
(Edit ADD) The Original Proposal was:
14-24 Log #3328 NEC-P14(501-4(A)(1)(a))
The history is in the 2005 cycle ROP/ROC. Check the "Current & Prior Editions" tab and then the 2005 drop menu, then the "Read the archived revision information" link, From there you're on your own.
(Edit ADD) The Original Proposal was:
14-24 Log #3328 NEC-P14(501-4(A)(1)(a))
Last edited:
- Status