Re: [RE-wrenches] Low array voltage stumper on legacy system

Mike, Jay's suggestion to turn off string three, the low one, is good. Plus I can guide the homeowner by phone, thus avoiding the cost of another site visit, so that adds appeal. I just spoke with him. While he lacks the DMM and DC amp clamp, he is going to record V and I in and out for each

Re: [RE-wrenches] Low array voltage stumper on legacy system

www.SpiritSolar.net From: Allan Sindelar [mailto:al...@sindelarsolar.com] Sent: Friday, August 26, 2016 2:12 AM To: RE-wrenches Subject: Re: [RE-wrenches] Low array voltage stumper on legacy system Steve, Yes, in the same sequence: 75.5V, 73.8V, 73.9V, 74.0V. All just about what I'd expect. Brian, I

Re: [RE-wrenches] Low array voltage stumper on legacy system

Steve, Yes, in the same sequence: 75.5V, 73.8V, 73.9V, 74.0V. All just about what I'd expect. Brian, I have seen that with KC120s over the years - good Voc and Isc but no MPP. That's a known failure that Kyocera (to their credit) continues to warrant 15 years out. But I haven't seen it with

Re: [RE-wrenches] Low array voltage stumper on legacy system

Hi Allan, I would try turning off string #3 and see what happens to the vmp. I'm guessing it'll go up to a more normal voltage. I just had a very similar experience, also BP modules, very brown. 2 sets of 4 billion n series to a 12v system. One set was totally dragging down the VMP, I

Re: [RE-wrenches] Low array voltage stumper on legacy system

Brian Can you do a solmetric type test, when you performed the amp test the volts were at near "0" so the test does not show an accurate value, you said the modules are brown this is not good but are they checked because if so you are done needs new modules. I would suggest doing some additional

Re: [RE-wrenches] Low array voltage stumper on legacy system

If it is a module issue it could be bad solder joints, shorted diodes, or a combination of both. I just curve traced 12 12-year old KC120s - all except 2 tested fine for Voc with a DMM (2 were totally dead). However with the curve tracer they all exhibited more of an IV "angle" than a curve,

Re: [RE-wrenches] Low array voltage stumper on legacy system

Hello Allan, Did you check the Voc of each string? Is it possible that there could one or more shorted bypass diodes in the modules? Just a thought. Steve Bell Morningstar tech support On Thu, Aug 25, 2016 at 8:04 AM, Allan Sindelar wrote: > Wrenches, > Here's one I

[RE-wrenches] Low array voltage stumper on legacy system

Wrenches, Here's one I haven't seen before. 1997 grid-tie battery backup system that was one of my first, although actual installation was by another before I was licensed. 16 BP 275, 36-cell 12V modules, the standard of that time. Early Outback MX60 replaced C40 around 2005; array rewired to