[RE-wrenches] Code reviewer issue with array disconnect location

[Jason Szumlanski]

I feel for you, man. I think you will be able to argue this one with
690.14(B) like Ryan says.

I agree that combine box accessibility is a danger to public safety.
Back in the "old days" when I was working on my first systems in the
Caribbean, there were lots of unfused "combiners" made out of terminal
blocks completely exposed. I fried my share of lizards. Anyway, with the
right boxes and the required warning labels, the risk is lower, but the
safety issue could still help with your argument.

Are the DC Disconnects and AC Disconnects "readily accessible" on a
microinverter system on the roof under an array of modules? That's where
they (the connectors) are, after all. Let us know how this turns out...

Jason Szumlanski
Fafco Solar


-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Ryan
Mayfield
Sent: Thursday, November 17, 2011 3:41 PM
To: 'RE-wrenches'
Subject: Re: [RE-wrenches] Code reviewer issue with array disconnect
location

Jeff, 

Try pointing them to 690.14(B). This allows for PV source circuit
isolating
switches on the PV side of the disconnecting means. As you describe it,
the
dc disconnect at the inverter is the required PV disconnecting means and
you
can describe the combiner disconnects as source circuit isolating
switches.
This paragraph doesn't make mention of accessibility.

Good luck,

Ryan



-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Jeff
Yago
Sent: Thursday, November 17, 2011 11:57 AM
To: 'RE-wrenches'
Subject: Re: [RE-wrenches] Code reviewer issue with array disconenct
location

Here's another one of those reviewers that do not know what they are
reviewing and just cause added hours of lost time.  Large 112 kW array
mounted on top of structural steel beams above multi-story parking deck.
Beams straddle center up and down ramps so no parking spaces are lost.
Multiple rows of modules and require ladders to access.  Budget reviewer
deleted my design of grated walkways behind each row, so you must use
tie
offs to work on any part of system.

Each row includes a fused combiner box at center line, with individual
conduit from each grouped down centerline on high mounting then down to
inverter located outside on top deck.  Inverter includes both AC and DC
disconnects which are readable accessible. Other AC disconnects included
in
electric room and outside at meter.

Due to long runs from each array row back down to inverter, I specified
the
fused combiner boxes to include a DC disconnect option located in the
cover
(memory of Target Store conduit fire!) which not only allows
disconnecting
any single row without shutting down entire system, but also useful for
testing and service.

Reviewer demands this "disconnect" meet code requirement that a
"disconnect"
must be readable accessible.  I have told them we cannot separate this
disconnect from the combiner box and will not relocate these high
voltage
combiner boxes down at eye level on a raised parking deck where any
student
could gain access, so if they make an issue of this we will use a
different
combiner box that does not have this option (and also loose added
protection
of conduit runs between combiners and inverter).  However, I would like
to
refer to code and I see no mention of a combiner box as required by code
so
there is no reference to it having a disconnect. 

Suggestions?

Jeff Yago
DTI Solar Inc.


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