International Association of Electrical Inspectors [RE-wrenches]

Fri Mar 7 08:10:25 PST 2008

I find the position of this inspector interesting. There seems to be
much misunderstanding of UL and ETL positions on the use of the WEEB or
our UGC. Below are some notes from a past discussion I have had. UL is
currently being pressed to review these issues by some manufacturers and
state organizations.

Here is my review of UL1703.

 I went through UL1703 section 11 Bonding and Grounding.  Section 11.1
refers you to section 10 connection means. But the exception in 11.1
says this. 

 When the grounding means is a module or panel mounting member intended
to contact an array or structural member, the module grounding means are
not required to comply with the requirements of section 10.

 Section 10 discuses the connection means like bolts, lugs to wiring.
This does not apply to the WEEB or UGC.

             I do not have the National Electric Code but in my
experience the Code normally refers to both UL listing and UL standards.
But never says you most be UL listed this would be legally unacceptable
because it would exclude other testing organizations and this is against
federal law. 

If I was a PV manufacturer I would suggest strongly to UL that 45.1.1a
says I need to describe my acceptable methods but what grounding
standard am I to refer to since section 10 does not apply?  UL467 or
what? ETL has reviewed this and made a decision but UL and some
inspectors have not.

             This is the issue:  UL 1703 does not address grounding with
exception of a bolt, lug and wire or outside of Section 10. I think we
need to push the partners and organization to push UL to give the
standard they want to use for other grounding methods.  I believe the
grounding reference in 1703 needs to be changed. It should say something
like other grounding solutions shall meet or exceed UL 467 or some
standard yet to be created. This is not a new issue.  Electrical
manufacturer have been grounding equipment long before solar came along
and this would bring us into the same playing field of other electrical
manufacturers.  Unfortunately people seem to loss the point. UL is
basically two different organizations. First they are a testing lab and
by law they are not the only lab if ETL has performed the due diligence
and finds that under UL Standards the only applicable standard that can
be applied is UL467 then the local inspectors have to recognize this as
acceptable in the same manor they recognize a UL interpretation of the
standards. UL tests to the same standard and hold no more weight legally
than an ETL test. The second position of UL is to write testing
standards this is completely separate than UL testing and listing.
Because this grounding option did not exist when UL1703 was written and
there is no section of UL1703 that covers this grounding option both UL
and ETL need to define what standard does apply and this is what ETL has
done. In short this inspector needs to read UL1703 and then make a case
for his position but he is going against what a national recognized lab
has defined and some people may make the argument he does not have that
authority to do so. I can not see his position since UL1703 clearly has
no wording on how to test alternative grounding options.  

Expand my thinking if you feel I am wrong. 

Chris Meier

Product Manager

UniRac, Inc.

1411 Broadway Blvd. NE

Albuquerque, NM   87102-1545

Ph:  505-242-6411 

Fx:  505-242-6412

Email:  chrism at unirac.com 

Web:   http://www.unirac.com

-----Original Message-----
From: William Miller [mailto:wrmiller at charter.net] 
Sent: Friday, March 07, 2008 12:17 AM
To: RE-wrenches at topica.com
Subject: International Association of Electrical Inspectors
[RE-wrenches]

Colleagues:

As it so happens, the IAEI is holding a three day seminar here in our 

county seat.  The agenda included two half day sessions on PV
installation 

code compliance and inspections.  I attended one of the sessions 

today.  The first presenter is a plan checker with the City of San
Carlos 

California.

The first issue discussed was generated by a question from an installer
and 

was on the subject of fusing parallel strings.  I was under the
impression 

that John Berdner's position as expressed in his white paper on fusing
of 

strings was pretty well accepted in the industry.  This has been
discussed 

thoroughly here in this forum.  The only caveat to Berdner's logic is
there 

must be some proof that the inverter can not contribute to PV fault 

current, even in a failure of the inverter.  Proof can come in the form
of 

results of independent testing and a statement from the manufacturer.

The presenter does not accept this logic.  His opinion is that, if the
PV 

manufacturer lists a maximum fuse size in any literature, an installer
must 

install a fuse.  The mere mention of a fuse in product literature means 

that, unless specifically stated otherwise, the manufacturer requires
one 

and manufacturer's requirements can not be waived by any language in the
NEC.

Furthermore, the presenter is not allowing use of the Wiley Electronics 

WEEB clips in his jurisdiction because the ETL listing for these clips
is 

under UL467 which applies generically to the grounding of non-current 

carrying metallic parts.  His problem is that unless the listing is
under 

UL1703, PV systems, the 467 listing does not allow for their use in PV
systems.

I sent an e-mail then and there to Wiley asking for clarification.
Problem 

is, I just ordered and received about $1,000 worth of WEEB clips and all
of 

the local inspectors where in the room hearing how they should not allow
me 

to use these as accepted grounding.  After the session I noticed that
Wiley 

addresses the 1703 versus 467 on their website at this 

address:  http://www.we-llc.com/WEEB.html  See the Summary for
inspectors 

section.

Do any of you on this list do business in San Carlos, and if so, how
ever 

do you get anything past plan check?  Furthermore, I assume most of you
are 

avoiding the use of fuses in string quantities of two or less, so this 

school of thought is going to cost you (and your customers) some cash.
How 

do you all feel about this?  Lastly, is anyone here using WEEB clips and

have you had their legality questioned?

Thanks for your input.  I apologize for being such a curious so and so.

William Miller

-- _________________________________

William Miller

Miller Power and Communications

Voice :805-438-5600     Fax: 805-438-4607

email: wrmiller at mpandc.com

http://mpandc.com

License No. C-10-773985

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