[RE-wrenches] Generator and Enphase

[Mark Frye]

Eric,
 
I do not have direct experience with this but have been exploring the issue
for a project I am currently doing.
 
My response will be to take the trouble to interconnect the Enphase
inverters on the line side of the tranfer switch so that the inverters can
never be connected to the generator.
 
Here are the reasons why:
 
1 - Enphase states that any such application is considered an "off-grid"
application which voids their warrenty. As I am installing under the
California CSI program, I am required to provide a 10 year manufacture
equipment warranty so I cannot afford to install the inverters in a
dis-allowed manner.
 
2 - Enphase states that the waveform of the generator may be "clean" enough
such that the inverter may attempt to syncornize and connect to it as if it
were the utility. If this were to happen Enphase believes the inverters will
ruin the generator regulator before the generator ruin the inverter. I don't
want to be the one to run the experiment to find out which would be which.
 
3 - I considered a contactor on the output of the inverters, such that the
inverters would isolated by a loss of line voltage, requiring some form of
reset. Ulitmately my customer agreed with me that this was an undesirable
constraint on the operation of an otherwise reliable grid-tied system and it
was not clear that this would satify the warranty issue.
 
Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  
 

  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Eric Thomas
Sent: Saturday, March 26, 2011 2:09 PM
To: re-wrenches at lists.re-wrenches.org
Subject: [RE-wrenches] Generator and Enphase


I have a customer with a "30A Mechanically Interlocked Breaker" for their
generator feed at the main panel. My question is: If the home power is
transferred from utility to generator power, will the backfed PV see the
generator as grid power and sync up and produce? This is a nice Honda
Generator so the power should be fairly clean. Any experiences are
appreciated.

Take Care,


Eric Thomas
Solar Epiphany LLC
(206) 919-3014
www.solarepiphany.com


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