[RE-wrenches] Module Load Rating

[Rich Nicol]

Hi Wrenches -

I've noticed discrepancies in load rating methods for various modules and
wondered if there was any insight from the installer community.  REC claims
113 PSF, Sharp claims only 50PSF. Solarworld notes 50PSF load rating, but
113 PSF snow load rating. I'm assuming the difference is that snow load
rating is greater because its assumed to be widely distributed, but yet its
still per square foot so perhaps not.  Is a Sharp module such as the
240NUQ-240F2 as durable as REC, Evergreen, Solarworld etc and they are just
more honest in their portrayal of load rating.

Thanks for your help,

Rich

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Gary Willett
Sent: Monday, October 03, 2011 4:33 PM
To: re-wrenches at lists.re-wrenches.org
Subject: Re: [RE-wrenches] interrupting current calculations used to
determine the interrupting of the AC equipment.

 

James:

I believe your PE is referring to the short circuit current calculations of
110.10, and the 110.24 marking requirements for AFC (Available Fault
Current). The utility company should be able to give you the AFC at the
secondary of their transformer, or better yet - at the service equipment.

The short circuit current rating of the utilization equipment, and the AIC
(Available Interrupting Current) rating of the OCPD in the utilization
equipment, must exceed the AFC.

Regards,

Gary Willett, PE







From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of James
Rudolph
Sent: Monday, October 03, 2011 1:54 PM
To: RE-wrenches
Subject: [RE-wrenches] interrupting current calculations used to determine
the interrupting of the AC equipment.

 

Dearest Wenches,

    I received an e-mail from PE reviewing one of our projects to build, and
this is what they wrote-

No interrupting current calculations were included.  It is suggested the
utility company be consulted for available at the service entrance and these
values be used to determine the interrupting of the AC equipment.

Does any one out there have experience dealing with this issue, or have the
ability to shed some light on this subject.

Many thanks in advance,

-- 
James B Rudolph
NABCEP Certified PV Installer









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