NFPA 70 ? May 2001 ROP
(Log #740)
5- 71 - (250-8 and Exception (New)): Reject
SUBMITTER: Dan Leaf, Palmdale, CA
RECOMMENDATION: Revise first sentence:
Wire type Grounding grounding conductors and bonding jumpers shall be connected by exothermic welding, listed pressure connectors, listed clamps, or other listed means.
Add:
Exception: Machine screws shall be permitted for solid No. 10 and smaller conductors, where used for no other purpose.
SUBSTANTIATION: Equipment grounding conductors may be raceways, cable armor, cable tray, cablebus framework, etc. Screws/bolts are used in many applications for bonding/grounding continuity such as receptacles, switch yokes, box covers, faceplates, cabletray and cablebus framework, etc., where there is direct metal-to-metal contact, and are indicated in
Sections 250-28(a); 250-102(a); 250-126(1); 250-148(a); 250-136(a); 370-40(d); 410-58(b)(3); 550-11(c)(4); 551-55(c),(2)(3); 551-56(b) Exception; 552-56(c)(2)(3), and inferred by 250-98. While some of these may be covered by listing, all are not. A common grounding or bonding connection in boxes is by a machine screw in a tapped hole covered by Section 370-40(d).
PANEL ACTION: Reject.
PANEL STATEMENT: Machine screws are used to secure conductor pressure connectors. Section 250-8 also covers connectors other than the wire type such as conduit grounding hubs.
NUMBER OF PANEL MEMBERS ELIGIBLE TO VOTE: 17
VOTE ON PANEL ACTION: AFFIRMATIVE: 17