[RE-wrenches] Accessibility of Equipment on Roof was Are PV Systems Mechanical Equipment?

[Kent Osterberg]

Jason,

It seems to me that two of the exceptions in 240.24 may apply to your 
situation. Most significantly (4) For overcurrent devices adjacent to 
utilization equipment that they supply, access shall be permitted to be 
by portable means. Thus using a latter to access the ac combiner on the 
roof should be permitted. There should also be an accessible disconnect 
elsewhere (at the panel feeding the combiner for instance.) That (may) 
makes the breakers in the ac combiner supplementary and thus they 
wouldn't have to be accessible.

Kent Osterberg
Blue Mountain Solar, Inc.
www.bluemountainsolar.com
  

On 2/8/2013 7:27 AM, Jason Szumlanski wrote:
> Oh, yes - that is a great application for the MNPV-AC. I didn't mean 
> to imply there isn't a good use for them. In this particular instance 
> the three MVPV-AC's are really subcombiners that get all get tied 
> together in another subpanel at ground level. They really were not 
> necessary, but made it more convenient and cost effective.
>
> It's just interesting how Midnite advertises that they can be mounted 
> as flat as a 3:12 pitch. What application would allow this mounting 
> angle where it is still readily accessible? The spec/advertising seems 
> to imply that these can be roof mounted in an AC string combining 
> application.
>
> The Soladeck combiner with fuses would appear to be non-code compliant 
> in any situation. I would love for someone to refute that in a 
> convincing way given the access requirements in 240.24(A).
>
> *Jason Szumlanski*
> /Fafco Solar/
>
>
> On Thu, Feb 7, 2013 at 7:31 PM, jay peltz <jay at asis.com 
> <mailto:jay at asis.com>> wrote:
>
>     Hi Jason,
>
>     Is it possible to install them on the side of a building?
>     And Dan's suggestion for the remote midnite might be perfect.
>
>     jay
>
>
>     On Feb 7, 2013, at 3:55 PM, Jason Szumlanski wrote:
>
>>     Jay,
>>
>>     I assume you mean pitched roofs, or not readily accessible flat
>>     roofs. This particular project happens to be a flat commercial
>>     roof, but with no permanent ladder or hatch. I really didn't have
>>     to use the MNPV6-AC's, but it made sense in this case (excluding
>>     the access issue).
>>
>>     Looks like my options are to remove the combiners or install a
>>     permanent access. Neither are fun options. Live and learn...
>>
>>     *Jason Szumlanski*//
>>     /Fafco Solar/
>>
>>
>>
>>     On Thu, Feb 7, 2013 at 6:27 PM, jay peltz <jay at asis.com
>>     <mailto:jay at asis.com>> wrote:
>>
>>         I'm with your inspector on this.
>>
>>         I don't install fuses or breakers on roofs
>>
>>         jay
>>
>>         peltz power
>>
>>
>>         On Feb 7, 2013, at 12:02 PM, Jason Szumlanski wrote:
>>
>>>         While I haven't completely convinced the latest inspector
>>>         about PV not being mechanical equipment, I'm running into
>>>         another issue.
>>>
>>>         I decided to try out the new Midnite MNPV6-AC combiner for
>>>         Enphase circuits. Because there are overcurrent devices
>>>         inside, the inspector now insists that NEC 240.24(A) applies
>>>         and that the enclosure must be readily accessible, meaning
>>>         you have to reach it without a ladder. That would seem to
>>>         make the MNPV6-AC as a roof mounted solution, or Soladeck
>>>         combiner boxes, or any other combiner box incorporating
>>>         overcurrent protection, pretty much useless on a pitched
>>>         roof or flat roof without a permanent access ladder or hatch.
>>>
>>>         I'm debating whether to go to battle on this one or just
>>>         capitulate.
>>>
>>>         *Jason Szumlanski*//
>>>         /Fafco Solar/
>>>         /
>>>         /
>>>         P.S. To answer benn's question, there is no definition of
>>>         'mechanical,' but it does define 'equipment,' and it's clear
>>>         to me that PV does not fit the description.
>>>         mbers.re-wrenches.org <http://mbers.re-wrenches.org/>
>>>
>

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