[RE-wrenches] Wire management dual axis tracker

[Dana]

We install the array junction box (with breakers) on the upper portion of
the tracker & use SOWA cord for the drop with strain relief on both ends.
The lower box has the conduit back to the power center or building breaker
for Grid tie. Check with your AHJ but this cord is sunlight-oil-gas rated, &
comes in many gauges. Probably not the least expensive option but never had
one fail in 20+ years. Allow enough for a full rotation but not so much it
gets flailing about in the wind.  

 

I build my own extension cords using the same and have cord that has been on
job sites for 20 years now. Again, not cheap but they last & last. 

I have replaced various flex non metallic seal tight conduit installations
by others when it has cracked. Also at cold temps the nmst flex conduit does
not bend very happily.

 

----------------------------------------------------------------------------

Dana Orzel 

Great Solar Works, Inc -  NABCEP # 051112-136

E - dana at solarwork.com  - Web - solarwork.com 

O - 970.626.5253  C - 208.721.7003

"Responsible Technologies for Responsible People since 1988"  

P Please consider the environment before printing this email.

 

 

From: RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] On
Behalf Of Ray Walters
Sent: Monday, November 30, 2015 8:35 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Wire management dual axis tracker

 

We used to  just bundle the PV cables and secure them close to the pivot
point at both the rack and the pole with insulated wire loom clamps.  We
always made a big enough loop to handle full articulation, but not too long
so they wouldn't catch on the Combiner box, etc.  We also started using
braided ground strap, instead of stranded #6.  Braided is made for movement,
stranded #6 would strain harden and break off at the connector.
I'm not sure how flex conduit would do.  It definitely could break out of a
plastic J box, I would think.  The back and forth motion eventually wears
out things not really made to move.  I had lots of trouble with this issue.
Finally, don't be greedy on tracker settings, I'd keep the total range of
motion to less than a full 180 degrees Azimuth, and probably limit the tilt
some too. 



R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer, 
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 11/30/2015 8:21 PM, Mac Lewis wrote:

Hi Wrenches, 

 

I'm looking for advice on the best way(s) to secure PV source circuit wiring
on a dual axis tracker.  I've never wired one up before and it seems tricky.
This particular tracker is 12 modules, 3 strings.  Is it best to run a
flexible conduit up the pole and leave plenty of excess conduit to create
large loops that fluctuate in size throughout the day?  What are some other
ideas?  How do you avoid abrasion over time?  

 

Thanks in advance


 

-- 

 

 

 

Mac Lewis

"Yo solo sé que no sé nada." -Sócrates






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