[RE-wrenches] Polaris gone bad?

[Matthew Sirum]

Greetings All,

I too have tried all of the methods discussed so far in this thread.
With regard to multi port tap block type connectors, I have used the
Burndy Unitap product the most and have had good results.  I like that
they come with anti-oxide compound already in them and that the set
screws have hex/allen socket heads.  I may have had one or two of the
set screws strip or come misaligned from the factory over the years,
but have not found any major failures or arcing/burning.  Overall I've
had a good experience with the Burndy Unitap.

I have used the Ideal/Buchanan Splice Cap Crimp Connectors in some
applications, but have not used them outdoors...  I thought at one
time I came across some literature for the nylon Splice Cap Insulators
used on these which indicated there may be an environmental
temperature rating related issue when considering them for PV install
work.  I'm looking for this spec now, but have not found it.  All I
find now regarding temperature is "Temperature Rating: 105° C
(221°F)".  Seems like using the Splice Cap Crimp Connectors with an
appropriately rated quality heat shrink tubing product instead of the
Splice Cap Insulator may also be a potential solution.

I have used electrical rubber insulating tape, electrical silicone
insulating tape, and electrical insulating mastic tapes to insulate
and seal many various uninsulated connectors and etc too...  Always
with an application of  quality electrical tape over them as well.

USE-2/PV Wire with MC Connector connected to THWN-2 with MC Connector
has worked well for me as well in a wire transition/junction box.  The
MC insulator boot sized for PV Wire may have been somewhat oversized
for the THWN-2 conductor.  It's always good to review the specs for
the connector product and the specs for the wire to ensure all will be
appropriately mated up in the field.

I have used butt splice crimp connectors with integrated insulating
shrink tubing such as the Molex Perma-Seal products.  When used with
the appropriate full cycle ratcheting crimping tool these make a very
nice connection.  Some of the butt splice connectors work well for
transitioning from fine stranded wire to standard stranded THWN-2
conductors such as in the case of working with some of the micro
inverter trunk cable systems etc.  I always apply a second layer of
quality heat shrink tubing over the connector and its integrated
shrink.  The use of these products and heat shrink tubing means
bringing a cord and heat gun or torch to the array install area to
seal the heat shrink.  I prefer a heat gun for better control and a
lesser likelihood of burning the connector, shrink, wire, or something
or someone.  Either way I can understand many folks may not want to be
dealing with heat shrink products or having their install crews doing
so, especially up on a pitched roof installation.

Some of the Molex Perma-Seal butt splice products have a connector
barrel made of tined copper and a 600V rating.  Molex identifies some
of these products for use in "consumer" and "industrial" applications.
Some have CSA and UL "certification" on their respective spec sheets,
but I have not researched the certifications by number to say for
certain if use in a PV system wire transition box or junction box is a
truly acceptable and compliant use for the product.

Have any of you researched or worked with these Perma-Seal or similar
products?  I am interested to learn more and fully understand what
their acceptable application are.  Other companies such as 3M and
Power Phase sell similar products, but often what I find are products
intended for the automotive and marine industry.  I absolutely do not
want to be using or suggesting automotive and marine products for use
in professional, code compliant residential and commercial electrical
work.

Link to Molex Perma-Seal Products:
http://www.molex.com/molex/products/family?key=heat_sealable_terminals&channel=products&chanName=family&pageTitle=Introduction&parentKey=solderless_terminals&utm_source=ds&utm_medium=lit&utm_campaign=ipd

Also; glad to see drain/weep holes mentioned too!  Even if water is
not getting in to the box/enclosure/body we want to make sure any
condensation that develops can drain out.  About 10-12 years ago I had
a project with a large outdoor wireway/trough/gutter which would hold
small amounts of water even though a number of drain/weep holes were
drilled in its bottom side...  A seasoned and friendly Electrical
Inspector showed me how to make "wicks" out of single strands of
wire...  Coiled the single strand flat to lay on the bottom inside of
the trough with a straight section of the single strand going through
a weep hole to draw any water out.  I put a few of these in the
trough...  It looked a bit funky but it seemed to help.

Best regards,

----MATT

Matthew Sirum
P.O. Box 1227
Greenfield, MA 01302-1227  USA
phone: +1.413.773.0611
email: MatthewSirum at gmail.com


------ Original Message Below ------

[RE-wrenches] Polaris gone bad?

eric at harvesthesun.com eric at harvesthesun.com

Thu Apr 6 10:35:58 PDT 2017


Wrenches,

We have been having Polaris connectors start to fail on older
installs. About 4 or 5 years ago we abandoned wire nuts in favor of
the much more pricey, but deemed safer Polaris insulated tap
connectors in our combiners. About a year ago we transitioned, about
80% away from Polaris to Buchannon connectors. We have had two recent
call-backs on systems downed due to Polaris connectors burning up
inside of boxes. (No damage beyond the connector itself). Recently we
interfaced with another solar install firm that has gone back to wire
nuts due to this same problem. Anyone else seeing this? Wondering if
this is an industry-wide issue regarding a Polaris manufacturing
defect or if we're still in the realm of isolated flukes.

Eric
SunHarvest
(530) 559-5023