[RE-wrenches] String Inverter compatible with Positive-Grounded PV Array

[August Goers]

There is some scuttle about just installing regular non-isolated
(transformerless) inverters with old SunPower positive grounded mods and
setting the expectation with clients that there may be some losses due to
PID. But, overall having a new inverter that is likely to be more reliable
with monitoring might be worth it. I had heard that PID losses can be as
much as 50% but I think that might be some of the very oldest SunPower mods
dating back to the early 2000s. By the time 2012 rolled around, maybe the
PID issue was almost gone anyway, just speculation.

I can't say we've done this yet except for a couple of Enphase projects
with old SunPower mods. So far so good.

Best,

August




On Wed, Aug 27, 2025 at 12:43 PM Richard Scott via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> You Love Solar sells SMA SB6000U capable of positive ground systems.
> https://youlovesolar.com/collections/inverters/products/sunny-boy-6000us-1
>
> https://youlovesolar.com/pages/switching-from-negative-to-positing-grounding-for-older-sunpower-systems
> You might try calling to see if they still do repairs.
>
> Richard
>
> On Wed, Aug 27, 2025 at 11:54 AM Travis Knipple via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
>> Hi all,
>> I'm trying to retrofit an old SMA/Sunpower system with a + grounded Array.
>> What options are out there for a new string inverter to put in these
>> systems (if any)?
>> Thanks,
>>
>> --
>> Travis Knipple
>> Senior Engineer
>> Hudson Solar Solutions LLC
>> Rhinebeck, NY 12572
>> 518-539-8040 x408 | travis at hudsonsolarsolutions.com
>>
>> PVIP# PV-111821-013612
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