[RE-wrenches] Best practices for conduit penetration on roof

Mon Nov 26 15:37:48 PST 2012

JASON:

I talked to Steve Capozzi of SolaDeck and he sent me additional info 
about the circuit breakers:

    _Manufacturer_:  ABB

    _Terminal Temp Rating_:  75C / 167F

    _Reference Temperature_: 20C / 68F

    _Ambient Temp Derating_:

        30C/86F = 18.7A
        40C/104F = 17.3A
        50C/122F = 15.8A
        60C/140F = 14.1A
        70C/158F = 12.2A

My concern is that we may be attempting to use an interior rated AC 
breaker in a roof-deck-mounted NEMA3-R enclosure.

In an Enphase application, with the maximum of 17 inverters per AC 
Source Circuit, the continuous current will be 0.9A x 17 x 1.25 = 19.1A. 
This exceeds the 30C/86F trip current of 18.7A.

The interior temperature of the SolaDeck could very likely approach the 
60C/140F trip current of 14.1A.

It seems to me that "nuisance trips" could be a high probability event.

Does anyone have any field experience using this Soladeck option for a 
AC Source Circuit Combiner Box (SCCB)?

Another issue, at least in some jurisdictions, is the requirement for a 
roof-top AC Disconnect.

The SolaDeck, when used as an AC SCCB, may not meet the NEC Article 100 
requirements in some jurisdictions for "readily accessible" because a 
tool is required to open it.

Regards,

Gary Willett, PE
Icarus Engineering LLC

Icarus Solar Services LLC

On 11/26/2012 2:21 PM, Jason Szumlanski wrote:
> I did get some pictures and info from Soladeck. Here are some links:
>
> Pics:
> https://docs.google.com/open?id=1BpiL-1SdSNNsj4wPMQrFCLHH7JT2dek_KftSJl06QLqc0yhJ_1t5oij0aEA6
> https://docs.google.com/open?id=1cVuhZGeQNHL1IvGvNBa7v93oZyGBvjxCv5yq4AmoyJeDAITxvgMqgECR2yTv
> https://docs.google.com/open?id=1umslTplnFyZG1eNCZE-MMi_OqrSeirFCPRBl9mFNZJ2gQkBjM5LEXnaPKy2l
> Specs:
> https://docs.google.com/open?id=13KLAuxUHOR9al7-36reDSJJ7IMnqV3ANPnJILPnrj2xcAi0ksRj67ifKIe7R
> https://docs.google.com/open?id=1kvPFcDc1vruS3W_aONlXyIHm1T8-qi4vTpTwGGJ7H0eIwuZ-5e6zrM1CcND5
> https://docs.google.com/open?id=1lM8FtYl9HiYohru32UA_Gb1tXZKZ5iw-8tnSu1Un6g4vcklLL-DK1qLPMdsB
>
> I was told Soligent can source the combiners for you (and me).
>
> *Jason Szumlanski*//
>
> /Fafco 
> Solar/<http://www.wisestamp.com/apps/wordpress?utm_source=extension&utm_medium=email&utm_term=wordpress&utm_campaign=apps>
>
>
> On Mon, Nov 26, 2012 at 1:50 PM, Jason Szumlanski 
> <jason at fafcosolar.com <mailto:jason at fafcosolar.com>> wrote:
>
>     I just called Soladeck and they are sending me some more info on
>     availability. I'll pass it along when I get it. I didn't realize
>     they made an AC roof mounted string combiner solution. That's a
>     huge help for 2 or 3 string Enphase installations (they make both
>     combiners).
>
>     While on the subject, we recently started using the Enphase cable
>     couple with Type TC-ER cable to extend cabling to junction boxes
>     when necessary... No more wasting trunk cable connectors! I
>     suppose Type TC-ER could be used all the way to the main
>     distribution panel, thereby eliminating junctions on the roof, but
>     I haven't looked into the cost/benefit of that idea.
>
>     *Jason Szumlanski*
>
>     /Fafco Solar/
>
>
>
>     On Mon, Nov 26, 2012 at 1:26 PM, Gary Willett
>     <gary at icarussolarservices.com
>     <mailto:gary at icarussolarservices.com>> wrote:
>
>         NICK:
>
>         I could not find the AC model numbers you provided on the
>         SolaDeck web site. Do you know the manufacturer, and the
>         voltage and temperature ratings, for the 2-pole 20A AC breakers?
>
>         Regards,
>
>
>         Gary Willett, PE
>         Icarus Engineering LLC
>
>         Icarus Solar Services LLC
>
>
>         On 11/26/2012 11:54 AM, Nick Soleil wrote:
>>         Hi wrenches;
>>
>>         SolaDeck Models 0760-41AD and 0766-41AD are rated for up to
>>         60A at 240Vac.
>>
>>         It can be ordered with DIN rail mounted AC breakers and a
>>         combiner kit.  The 2 - 20A circuit combiner kit is part 0760K2AC.
>>
>>         I'd recommend checking with a distributor or on SolaDeck's
>>         website for the most current information.
>>
>>         Nick Soleil,
>>         Enphase Energy
>>
>>
>>         On Sun, Nov 25, 2012 at 7:44 AM, Kent Osterberg
>>         <kent at coveoregon.com <mailto:kent at coveoregon.com>> wrote:
>>
>>             My understanding has been that the Soladeck has only been
>>             listed for DC wiring. Perhaps they have a manufacturer
>>             rep on RE-wrenches that can clarify.
>>
>>             Kent Osterberg
>>             Blue Mountain Solar, Inc.
>>             www.bluemountainsolar.com <http://www.bluemountainsolar.com>
>>
>>
>>
>>             On 11/25/2012 6:20 AM, Dave Palumbo wrote:
>>
>>                 Rich,
>>
>>                 We have been using SolaDeck PV roof mount enclosure.
>>                 NEMA 3R with a flashed
>>                 penetration. Can use for combining, or simply as a
>>                 pass through box.
>>
>>                 Dave
>>
>>                 David Palumbo
>>                 Independent Power LLC
>>                 462 Solar Way Drive
>>                 Hyde Park, VT 05655
>>                 www.independentpowerllc.com
>>                 <http://www.independentpowerllc.com>
>>                 NABCEP Certified PV Installer
>>                 Vermont Solar Partner
>>                 25 Years Experience, (802) 888-7194
>>                 <tel:%28802%29%20888-7194>
>>
>>
>>
>>
>>                 -----Original Message-----
>>                 From: re-wrenches-bounces at lists.re-wrenches.org
>>                 <mailto:re-wrenches-bounces at lists.re-wrenches.org>
>>                 [mailto:re-wrenches-bounces at lists.re-wrenches.org
>>                 <mailto:re-wrenches-bounces at lists.re-wrenches.org>]
>>                 On Behalf Of Rich Nicol
>>                 Sent: Sunday, November 25, 2012 8:11 AM
>>                 To: 'RE-wrenches'
>>                 Subject: [RE-wrenches] Best practices for conduit
>>                 penetration on roof
>>
>>                 Wrenches,
>>                 We typically run conduit for roof mounts over the
>>                 edge of the roof to the
>>                 eaves, rather than penetrate the roof whenever
>>                 possible. An upcoming
>>                 installation on an freshly asphalt shingled roof
>>                 requires that we penetrate
>>                 the roof for the conduit run (Enphase). I'm wondering
>>                 if there are any
>>                 suggestions for preferred flashing products and best
>>                 known practices. It's
>>                 always seemed to me that the typical Oatey type
>>                 flashing dries and cracks
>>                 eventually.
>>                 Thanks for your insights..
>>                 Rich
>>
>
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