That's what I was thinking, along with many others. It wasn't UL, its CMP-5
5-84 Log #3365 NEC-P05 Final Action: Accept in Principle
(250.8)
____________________________________________________________
Submitter:
Paul Dobrowsky, Holley, NY
Recommendation: Revise text to read:
250.8 Connection of Grounding and Bonding Equipment.
ETC.........
Panel Statement: The panel action on this proposal intends to incorporate
acceptable concepts included in other proposals on this section. The panel also
incorporated language from Comment 5-40 (log #2137) of the 2004 Report on
Comments, which is Proposal 5-78 in this Report on Proposals.
Number Eligible to Vote: 15
Ballot Results: Affirmative: 15
____________________________________________________________
From the draft
250.8 Connection of Grounding and Bonding Equipment
[ROP 5?84].
(A) Permitted Methods. Grounding conductors and bonding
jumpers shall be connected by one of the following
means:
(1) Listed pressure connectors
(2) Terminal bars
(3) Pressure connectors listed as grounding and bonding
equipment(4) Exothermic welding process
(5) Machine screw-type fasteners that engage not less than
two threads or are secured with a nut
(6) Thread-forming machine screws that engage not less
than two threads in the enclosure
(7) Connections that are part of a listed assembly
(8) Other listed means [ROP 5?84]
The other opinion is that if the ungrounded conductors carry the fault current, a failed connection will be know to the user (ie. light doesn't work, stove doesn't work, etc).
Now, if the failure occurs in the connection on the grounding side, and the breaker has just been simply reset, the untrained user will have know way of knowing what just has taken place.
BTW, I have not looked at the difference of the UL testing between the two different standards. But I will....
Jim
New Hampshire