[RE-wrenches] Concentrics at 250 volts plus
August Goers
august at luminalt.com
Tue Jul 15 07:46:32 PDT 2014
Hi Kelly and William,
Certainly NEC 250.64(E)(1) requires ferrous metal raceways containing a GEC
to be bonded at each end. 250.97 requires us to assure that we maintain
electrical continuity of raceways and metal sheaths to ground. As far as I
can tell this includes both ends of the raceway. William, if you have a
concentric knockout on one side I would think that you do have to use a
bonding bushing for that side and then using a grounding locknut on the
other side. At least that’s what our inspectors in San Francisco seem to
think.
Kelly, do you have any code section you can point to which shows that
bonding one side of the conduit is sufficient for circuits over 250 V to
ground with a EGC?
Best,
August
*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
Behalf Of *William Miller
*Sent:* Monday, July 14, 2014 10:47 PM
*To:* 'RE-wrenches'
*Subject:* Re: [RE-wrenches] Concentrics at 250 volts plus
Kelly:
Just as I suspected. I wish you could be here to share the lunch I have
earned on my bet.
Thanks,
William
[image: Gradient Cap_mini]
Lic 773985
millersolar.com <http://www.millersolar.com/>
805-438-5600
*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org
<re-wrenches-bounces at lists.re-wrenches.org>] *On Behalf Of *Kelly Larson
*Sent:* Monday, July 14, 2014 10:16 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Concentrics at 250 volts plus
Hi William,
The requirement for bonding on BOTH ends comes when the wire though the
conduit is a GEC. For EGC, just one end of the conduit is sufficient.
Blessings,
Kelly
~~~~~
Kelly Larson
707-223-3209
Box 504
Ukiah, CA 95482
Electrical Engineer
NABCEP Certified Solar PV Installation Professional
IREC Certified Master Trainer for Photovoltaic Installer
CA Electrical Contractor# 868189
SolarKelly.com
On Jul 14, 2014, at 3:11 PM, William Miller wrote:
Friends:
Please help us settle a crew debate before we come to blows: for circuits
250 volts and higher, do we need to bond EMT at both ends? Or, if there is
bonded cabinet with a concentric on one end and a solid, bonded metal
cabinet on the other, do we need a bonding bushing on the concentric end?
I say a conduit needs to be bonded only on one end. My misguided employee
says both ends. Both cabinets are independently bonded.
Thanks in advance.
William
Miller Solar
_______________________________________________
List sponsored by Redwood Alliance
List Address: RE-wrenches at lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive:
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
www.members.re-wrenches.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140715/b1e329a3/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 1460 bytes
Desc: not available
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140715/b1e329a3/attachment-0005.jpg>
More information about the RE-wrenches
mailing list