[RE-wrenches] Unusual problem with SMA TL inverter on metal roof

[Exeltech]

Do NOT connect chokes from any of the PV leads to ground.  It will create a DC path where no DC path should exist.  It's hazardous, and can/will destroy the inverter.

Inductance is indeed an offset to capacitance in many situations .. but this is not one of them.


Dan Lepinski

Professional Inverter Design Engineer (among many other things...)


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On Fri, 3/14/14, Chris Mason <cometenergysystems at gmail.com> wrote:

 Subject: Re: [RE-wrenches] Unusual problem with SMA TL inverter on metal roof
 To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
 Date: Friday, March 14, 2014, 9:07 AM
 
Typically when capacitance is a problem, the answer is inductance. Have you looked at adding some chokes between the DC negative and ground to counteract the capacitance?
 
 
 On Thu, Mar 13, 2014 at 10:31 PM, Marco Mangelsdorf <marco at pvthawaii.com> wrote:
 
 Friends,
 
 We have run across an odd technical problem at our commercial install at a laundromat on our island.   Attached is the description of the issue from SMA.  We don’t know much except that we are switch out the TL inverters to the old style US inverters because SMA has no fix for the phantom ground tripping.  The issue is beyond our feeble understanding.
 
Any observations to share?
 
Thanks,
 
marco