[RE-wrenches] Article 690, or The Haves Vs. Have Nots

Wed Apr 30 05:08:17 PDT 2014

Each microinverter string needs dedicated overcurrent protection. If
combining strings on the roof for a single run back to the interconnection
point, you need each string to have it's own breaker/fuse. The other option
is to run each string back to the interconnection point separately, but for
a 10kW system you have to do a supply side connection anyway on as typical
200A service, so combining strings somewhere is necessary, and a single run
from the roof makes sense in many cases.

Jason Szumlanski

Fafco Solar

On Tue, Apr 29, 2014 at 6:40 PM, jay peltz <jay at asis.com> wrote:

> Follow up to Bill's point.
>
> For Micros I've installed a disconnect on the roof, but never a breaker or
> fuse
> Why install a breaker?
>
> jay
>
> peltz power
>
> On Apr 29, 2014, at 9:43 AM, Bill Hoffer wrote:
>
> Dave
>
> I agree, in the case of microinverters, you already have a main PV System
> disconnect at the Load Panel to shut down the system that is readily
> accesible.  I would consider the disconnect on the roof as a supplemental
> disconnect for the purposes of maintenance by authorized personal that only
> needs to be accessible.
>
> Bill
>
>
> On Tue, Apr 29, 2014 at 8:44 AM, Dave Click <daveclick at fsec.ucf.edu>wrote:
>
>>  I think 240.24(A)(4) allows the installation of the inverter OCPDs in
>> the SolaDeck hidden under a module.
>>
>>  *240.24 Location in or on Premises.*
>>  *(A) Accessibility.* Overcurrent devices shall be readily accessible
>> and shall be installed so that the center of the grip of the operating
>> handle of the switch or circuit breaker, when in its highest position, is
>> not more than 2.0 m (6 ft 7 in.) above the floor or working platform,
>> unless one of the following applies:
>> ...
>> (4) For overcurrent devices adjacent to utilization equipment that they
>> supply, access shall be permitted to be by portable means.
>>
>>
>> And if panelboards / fused safety switches are allowed to have
>> screwed-down covers over the OCPDs, I'd think that installing a removable
>> module over these OCPDs would meet NEC. I guess an AHJ could argue that
>> this requires TWO covers be removed, unlike a panelboard or a switch.
>>
>> DKC
>>
>>
>> On 2014/4/29, 11:15, Jason Szumlanski wrote:
>>
>>  690.9(D) is not applicable to the original discussion because we were
>> talking about an Inverter output circuit, not a PV Source or Output circuit.
>>
>>  690.34 may apply if you call a SolaDeck with breakers a junction box,
>> but I can see that being a stretch in the mind of many.
>>
>>  My and Ray's question about the screws on the SolaDeck cover itself
>> requiring a tool to render it accessible is still an issue if the breakers
>> themselves need to be "readily accessible," but that would also apply to a
>> Midnite MNPV, which also has a cover with a screw.
>>
>>
>>  Jason Szumlanski
>>
>>>
>>> On 4/28/2014 5:57 PM, Bill Brooks wrote:
>>>
>>> Read 690.9(D) and 690.34. Not sure where this “hysteria—run for the
>>> border” sentiment is coming from.
>>>
>>>
>>> *690.9(D) Photovoltaic Source and Output Circuits. *Listed PV
>>>
>>> overcurrent devices shall be required to provide overcurrent
>>>
>>> protection in PV source and output circuits. The overcurrent
>>>
>>> devices shall be accessible but shall not be required to
>>>
>>> be readily accessible.
>>>
>>>
>>> *690.34 Access to Boxes. *Junction, pull, and outlet boxes
>>>
>>> located behind modules or panels shall be so installed that
>>>
>>> the wiring contained in them can be rendered accessible
>>>
>>> directly or by displacement of a module(s) or panel(s) secured
>>>
>>> by removable fasteners and connected by a flexible
>>>
>>> wiring system.
>>>
>>>
>>> This is not a change. Please help me understand the concern.
>>>
>>>
>>> Bill Brooks.
>>>
>>>
>>>
>>> *From:* re-wrenches-bounces at lists.re-wrenches.org [
>>> mailto:re-wrenches-bounces at lists.re-wrenches.org<re-wrenches-bounces at lists.re-wrenches.org>]
>>> *On Behalf Of *Ray Walters
>>> *Sent:* Monday, April 28, 2014 2:23 PM
>>> *To:* RE-wrenches
>>> *Subject:* Re: [RE-wrenches] (no subject)
>>>
>>>
>>> Interesting so does "require a tool" include taking a screw off the
>>> cover plate of the combiner box, too?
>>> What a game changer.  I'm going to Mexico for my next project; I'll
>>> actually enjoy even more being the sole AHJ on the project.
>>>
>>>  R.Ray Walters
>>>
>>> CTO, Solarray, Inc
>>>
>>> Nabcep Certified PV Installer,
>>>
>>> Licensed Master Electrician
>>>
>>> Solar Design Engineer
>>>
>>> 303 505-8760
>>>
>>> On 4/28/2014 2:52 PM, Michael Morningstar wrote:
>>>
>>> Readily accessible is now defined in the 2014 NEC. Installing OCPD’s
>>> underneath a module is a major faux paux, and I can’t imagine any AHJ
>>> thinking otherwise. Having to remove a module in order to reset a breaker,
>>> what a drag.
>>>
>>>
>>> "Capable of being reached quickly for operation, renewal or inspection
>>> without requiring those concerned to use a tool, to climb over, remove
>>> obstacle or other.”
>>>
>>>
>>> Michael
>>>
>>>
>>>
>>>
>>>
>>>
>>>  On Apr 28, 2014, at 10:29 AM, William Miller <william at millersolar.com>
>>> wrote:
>>>
>>>
>>>
>>>  You call it a solar panel, I call it a glass j-box cover plate.
>>>
>>> William
>>>
>>> Miller Solar
>>>
>>>
>>>  On Apr 28, 2014, at 9:21 AM, Jason Szumlanski <jason at fafcosolar.com>
>>> wrote:
>>>
>>> If that is the interpretation,
>>> I don't see how the breakers are "readily accessible" in a SolaDeck
>>> mounted anywhere, regardless of whether it is under a module. It
>>> requires removal of four screws (using a tool) to access the breakers
>>> inside the enclosure. It's all up to the AHJ. It has not been an issue
>>> locally here. I can see how other jurisdictions may not
>>> concur.
>>>
>>>
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