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

Wed Apr 30 07:17:51 PDT 2014

"
An AC breaker is far more likely to trip than a DC string fuse"

I completely disagree. We have never, not once, had to reset a tripped
inverter output circuit AC breaker that I know of, but have replaced many
dozens of DC string fuses and GFCI fuses in inverters, most of the time for
undiagnosed failures. There is a reason we keep a good supply of 1A, 15A,
and 20A Littlefuses in a drawer here.

Jason Szumlanski

On Wed, Apr 30, 2014 at 9:56 AM, Drake <drake.chamberlin at redwoodalliance.org
> wrote:

>  There are good reasons to want to put AC combiners under modules, but
> some reasons not to want to.
> 
> An AC breaker is far more likely to trip than a DC string fuse, due to the
> surge availability. As a PV system is designed to last a minimum of 25
> years, the installer might not be the one to sort out problems decades down
> the line.
>
> A strategy I prefer would be to use a SolaDeck as a junction box. Run
> small wires to a convenient AC combiner location.
>
>
> At 12:43 PM 4/29/2014, you 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 “hysteriarun 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 <303%20505-8760>
>
>
> 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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> William Hoffer
> 161 SE Fourth Ave
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