[RE-wrenches] Wire Management--was RE: Rooftop wiring

Thu Oct 15 21:41:59 PDT 2009

Aloha Solar Bozos
    It's hard not to be upset, but I don't believe that racking manufacturers should be held accountable for this alone.  I have always felt that the module manufacturers should be responsible for wire management.  Why are the module frames not constructed with channels in the frames for wire management; a snap in channel that could hold a few USE-2 conductors.  Perhaps the modules could snap together.  
    A few companies have provided solutions for competent wire management, especially for BIPV products.  But the majority of the module manufacturers leave the MC connectors loose, to be chewed on by squirells.  Like my neighbors squirells, a whole family got shorted out and fried chewing on the homerun cables in a Sunframe racked system.  The poor family chewed through the conductors, and then completed the circuit, with themselves in the middle.  
    These days, I am still utilizing wire clips, such as the stainless ones Wiley Electronics supplies.  Additionally, I run my USE-2 homeruns with UV zipties to the rails.  However, I look forward to a better solution!  
    The BP Integra system attempts to incorporate the module interconnects and homerun conductors into the system.  It has a channel on the top and bottom edge of the module, which allows for a few homeruns, and the conductors are contained in sidecaps on the sides of the array.  We finalled a 10 KW Integra system yesterday, and I love the attractive look.  However, aspects of the design could certainly be improved.  
            - The edges of the wire management channel seem a bit sharp, why not soften that edge.

            - The j-box mounting method is somewhat awkward.
            - The modules can wobble, when installed as per the design and installation manuals.

    Of course, it is easier to accomplish competent wire management when the frames and modules are integrated into a single system.  With all the new investements in our industry, maybe we will finally see some leadership here.

________________________________
From: August Goers <august at luminalt.com>
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
Sent: Thu, October 15, 2009 5:42:48 PM
Subject: Re: [RE-wrenches] Wire Management--was RE:  Rooftop wiring

Bill –

I can’t agree with you more about the lack of good products to
route and protect rooftop wiring in an effective and efficient manner. That
lead me to prompt the “Rooftop wiring” post in the first place.  It seems like
a wide open market but maybe it’s just too small (currently...) Brian Wiley
would probably have some good insight on this issue. Things are changing – we’ll
fix this issue sooner or later. 

-August

August Goers

Luminalt Energy Corporation
O: 415.564.7652
M: 415.559.1525
F: 650.244.9167

From:re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Bill
Brooks
Sent: Wednesday, October 14, 2009 4:07 PM
To: 'RE-wrenches'
Subject: [RE-wrenches] Wire Management--was RE: Rooftop wiring

Max,

Is the Minerallac clamp really rated as a bonding device? I
don’t think so. It may make an electrical connection, but I don’t think it is
nearly as good as a ground bushing. It is also made of cad-plated steel and I
don’t think it is as durable as EMT or a ground bushing with a cad plated
fastener. It probably doesn’t matter too much if it is just protecting
conductors and a bonding conductor between two rails, but I would not want to
rely on this for any circuits containing the final equipment grounding
conductor or main circuit conductors. Not something I would lose a whole lot of
sleep over—there are far bigger issues to solve. Of far more significance is
the overall wire management of USE-2 conductors in the array. Structure suppliers
still do a terrible job of providing an effective means of controlling and
protecting conductors—this is nearly a decade after the first commercially
available system was developed. Is anyone else ticked off about this???

Bill.

From:re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Max
Balchowsky
Sent: Wednesday, October 14, 2009 2:59 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Rooftop wiring methods between multiple
subarrays

Bill,
as you know, if the array is on a tilted roof (tile track bkts or fast jacks)
and the array is monolithic, all the wires go directly from under the panels to
the junction box ( I mis-spoke when I said Combiner box, I too don't see the
need for combiner boxes on residential systems ).We go directly from the weeb
ground lug into the junction box then down. The panels are bonded to the rails
with the  Weeb Bonding Clips.  If the array consists of tilted rows,
we've used either a bare copper wire tie wrapped to the EMT between rows or run
in the EMT (most rows are 18-24" apart depending on angle). What I've done
on the last couple of tilted row residential jobs is used the mineralac clamps
and EMT between rows (inspector has bought it as a "bond" between rows
then used the ground lug on the last row to take the ground into the junction
box and down..........

Max

________________________________

From:Bill Brooks <billbrooks7 at yahoo.com>
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
Sent: Tuesday, October 13, 2009 7:59:13 AM
Subject: Re: [RE-wrenches] Rooftop wiring methods between multiple
subarrays

Max,

I’m not sure I understand your scenario completely. The
WEEB-Lug, superior to the ILSCO product, is intended for grounding the rack to
the equipment grounding conductor. Each rail gets a WEEB-Lug and an EGC ties
all those rails together and takes the ground to the j-box to enter the conduit
system (don’t like combiner boxes on residential rooftops). The key is how to
effectively bond metal conduit. Bonding bushings or box fittings are the only
means I know of to do this.. As others have pointed out, the bushings currently
on the market are often not designed for outdoor use. This is particularly of
concern in high corrosion areas (where EMT is not recommended). 

My experience is that it is better to bond with indoor lugs than
not to bond at all. When I check old lugs in the field with cad-plated set
screws, they often still have a good bond even though the screw is fully
rusted. The key is the bond between the conductor and the lug, and the between
the lug and the metal it is attached to. If both surfaces are tight and no
oxygen is getting to the interfaces, the bond will stay for a very long
time—possibly the life of the system in a lower corrosion environment. The set
screw is mechanical pressure, not the bonding point—rust  locks it..
 It is best to use outdoor-rated equipment, but in some cases, it may be
impossible because the equipment may not be manufactured, since the market is
too small. Oh the joys of exterior wiring.

Bill.

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