[RE-wrenches] Just getting old?

[Darryl Thayer]

Was the inverter connected at the time of testing?  If so I suspect the
inverter is loading the solar array below Vmp

On Wed, May 17, 2023 at 11:23 PM frenergy via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Wrenches,
>
>              I've got a call from a customer that said their (my
> install) 17 year old GT system went dead. Basic stats: 23, Mitsubishi
> PVMF120EC3, label says V mpp= 17.6V and Voc = 22 V; top-of-pole; SMA
> SB3800U. Its one string of 23 PVs.  Full sun, 75 degrees ambient during
> testing. When I checked DC voltage at the inverter landings I got ~23-29
> volts (fluctuating) same at the input side of the DC switch.  These
> panels have the old gasketted 4-screw covered J-boxes and screw
> terminals inside, I removed the covers from three panels and got 9.5
> volts at the each of the panels' screw terminals,  all the wiring
> outside the boxes checks out.
>
>              The system had been functioning normally 3 weeks prior. I
> could check voltage at more panels I guess.  Ideas?
>
> Bill
>
> Feather River Solar Electric
> Bill Battagin, Owner
> 4291 Nelson St.(shipping)
> 5575 Genesee Rd. (USPS, UPS)
> Taylorsville, CA 95983
> 530.284.1925 Office/ 530.258.1641 Cell
> CA Lic 874049
> Solar powered since 1982
>
>
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