Grounding screw requirement [RE-wrenches]

[Mike Bernhard]

<x-flowed>

The 2008 code in ART 250.8 effectively addresses this issue.  250.8 
Connection of Grounding and Bonding Equipment (A) Permitted Methods (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.
Yes, this is new.  Yes it has been a generally accepted standard for some 
time.
At full Spectrum Solar we have virtually no issues with inspectors.
We actively engage them in discussion BEFORE we start a system in their 
jurisdiction and can usually work out any discrepencies between what they 
think and what we think.
Mike Bernhard
Master Electrician
Full Spectrum Solar

----- Original Message ----- 
From: "Aaron Wellendorf" <Aaron at stellarenergy.com>
To: <RE-wrenches at topica.com>
Sent: Thursday, February 21, 2008 12:29 PM
Subject: RE: Grounding screw requirement [RE-wrenches]


>
> Joe,
>
> The 2005 NEC 250.8 does not mention thread engagement standards, machine
> screws, or thread-forming screws. It requires use of a "listed means" of
> connection, no solder only connections, and forbids sheet metal screws.
> "Sheet metal screws shall not be used to connect grounding conductors or
> connection devices to enclosures."
>
> The "listed means" of connection most likely incorporates thread
> engagement standards in the listing testing process, but they are not
> spelled out. Probably because if you install the component in the listed
> manner you would meet the unstated standard. I would still like to know
> where an electrical thread engagement standard is found. I want to
> incorporate the standard into our training program. The NRTL's test to
> written standards and approve grounding connections and grounding kits
> (like Sq D's). Like Brian Wiley said, the standard may be mechanical and
> does not appear to be in the NEC.
>
> Thank you for pointing out the non-sheet metal screw requirement.
>
> Aaron Wellendorf
>
> Joe Felker wrote:
> <Look in 250.8 Connection of Grounding & Bonding Equipment
> <It permits the use of machine screws or thread-forming screws that
> <engage not less than two threads
>
>
> - - - -
> Hosted by Home Power magazine
>
> To send a message: RE-wrenches at topica.com
>
> Archive of previous messages: 
> http://lists.topica.com/lists/RE-wrenches/read
>
> List rules & how to change your email address: 
> www.mrsharkey.com/wrenches/etiquette.php
>
> Check out participant bios: www.mrsharkey.com/wrenches/
>
> Moderator: michael.welch at homepower.com
>
>
> 


- - - -
Hosted by Home Power magazine

To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at re-wrenches.org

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------


</x-flowed>