[RE-wrenches] Enphase installation details

[William Miller]

Colleagues:

We are in the middle of our first Enphase installation.  I have been 
working closely with the crew on this project and dedicated extra time 
because we knew we needed to develop some new procedures to accommodate the 
new technology.

My most surprising realization is that with the Enphase inverters, the 
roof-top wiring now has two levels of unprotected wiring, DC and AC.    I 
have been working on an analogy for the recent evolution of PV wiring 
standards and the best I can come up with is that the new norm is akin to 
wiring a rooftop air conditioning unit with SO and USE.  Flexible cords are 
more suited to portable, consumer connectable appliances in non-harsh 
environments.

We wrestled with two issues:  How to secure the AC wiring with a minimum 10 
year longevity -- and how to secure the DC wiring with the same life 
expectancy.  In a previous career I worked in the telecommunications 
industry.  In a telcom facility we had access to many layers of wire 
routing hardware and systems.  The PV industry has, in my opinion,  largely 
ignored wire management.  Ironically, telecom wiring is low voltage in an 
industrial setting and we can secure it systematically, whereas PV wiring 
is high voltage, often in a residential setting, outdoors, in high 
temperature and wet conditions and yet we are relegated to the ubiquitous 
and fragile cable tie as our prime methodology.  It is our corporate 
position that the plastic cable tie can not be counted on for longer that 
two years in an under-PV environment and, since we wire for a minimum 10 
year life expectancy, the plastic cable tie is not suitable.

Over the course of two days we developed robust and efficient techniques 
for securing the AC and DC wiring.  I'd love to share our procedures with 
this group, but due to extreme competition in our area, I must of necessity 
keep any procedures that give us a competitive advantage 
confidential.  This is unfortunate as my inclination is to teach, but 
it  is a reality in this business climate.

I hope the industry can eventually recognize some of these short 
comings.  The solar water industry died an early death because of economic 
pressures and shoddy workmanship.  It is possible that the solar electric 
industry of today can suffer some of the same if we can't preform to higher 
standards.

William Miller



Please note new e-mail address and domain:

William Miller
Miller Solar
Voice :805-438-5600     Fax: 805-438-4607
email: william at millersolar.com
http://millersolar.com
License No. C-10-773985
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