[RE-wrenches] Polaris gone bad?

[penobscotsolar at midmaine.com]

William,
   The only place we use splicing is in the transition box, where we
transition from USE/RHW or PV wire to THWN in conduit. We almost always
have this transition in smaller systems without need of a combiner box.
I suspect it is the same for others. In larger systems there is no need
for splicing anywhere with the use of combiner boxes.

Daryl



> Wrenches:
>
> I am wondering why the proliferation of splices in PV leads?  We all know
> splices are a weak link.
>
> We allow only one connection between a module and the feeder destination--
> be it a combiner, inverter or optimizer-- and it is an MC connector, one
> side of which is factory-made and provided by the module manufacturer.
>
> If one plans and pulls PV circuits with forethought, splices should not be
> necessary.
>
> If anyone wants to know more about how this can be accomplished, look at
> our web site or contact me off list.
>
> William
>
>> On Apr 8, 2017, at 10:05 AM, Glenn Burt <glenn.burt at glbcc.com> wrote:
>>
>> It is also worth noting that many of the SMA installation manuals
>> specifically say do not use wire nuts on DC wiring.
>> Of course choosing to ignore the manufacturers installation instructions
>> would be a NEC violation.
>> From: Drake
>> Sent: ‎4/‎8/‎2017 12:10
>> To: RE-wrenches
>> Subject: Re: [RE-wrenches] Polaris gone bad?
>>
>>
>> At 01:35 PM 4/6/2017, you wrote:
>>> Recently we interfaced with another solar install firm that has gone
>>> back to wire nuts due to this same problem.
>>
>> Wire nuts have the advantage of holding the wires tight with a spring.
>> The spring follows the cold flow of the copper over the years. A screw
>> type connection does not.
>>
>> When I service an old breaker box, usually the wires are loose under the
>> screw connections, especially on the neutral and grounding bars. Often
>> they are very loose, and I bet that the screws were tight after the
>> initial installation of the equipment.
>>
>> On old industrial control equipment, I've learned the hard way to
>> tighten all screws before doing anything in the box, as wires are prone
>> to fall out of the loose screw connections. Again, these connections
>> have the weakness of being held by terminal screws, with no spring to
>> follow the cold flow of the metal.
>>
>> With wire nuts, it can be a bit tricky to know if you have a good
>> connection, as the connection is hidden under the plastic cap. It is
>> good to pull hard on each wire separately to be sure it is securely
>> under the spring. It is crucial never to mix copper and aluminum under a
>> wire nut unless it is one specifically designed for the purpose. Unless
>> specifically listed, all out door wire nuts should be in a weather proof
>> box, and preferably taped.
>>
>> Drake Chamberlin
>> Athens Electric LLC
>> OH License 44810
>> CO License 3773
>> NABCEP Certified Solar PV
>> 740-448-7328
>> http://athens-electric.com/
>>
>> 	Virus-free. www.avast.com
>> _______________________________________________
>> List sponsored by Redwood Alliance
>>
>> List Address: RE-wrenches at lists.re-wrenches.org
>>
>> Change listserver email address & settings:
>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>
>> List-Archive:
>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>
>> List rules & etiquette:
>> www.re-wrenches.org/etiquette.htm
>>
>> Check out or update participant bios:
>> www.members.re-wrenches.org
>>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive:
> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>
>