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JohnC avatar image
JohnC asked

Generator Input Instability

Offgrid, Multiplus 48/5000, 225Ah fla batts, CCGX, 150/100 mppt. 2x generators, both with the same issue, see screenpic..

1624775299139.png

This shows the Multi charging/controlling to Absorb V. There's 2 sections, the first with a Yamaha 6kVA, the second with a Scorpion 2.2kVA. My problem is that the V is varying over ~2V and the Amps ~4A. Target V today is ~58.6V (Temp Comp, cold batts), but the Multi never actually registered Abs, it stayed in Bulk. The mppt, set 0.1V higher than than the Multi, actually found Abs from the V spikes and locked in, though only producing ~100W in foul cloud.

I can settle it down using 'Weak AC', but this comes with other issues. Recently was able to remove that when I found a hot ac cable joint and repaired it. Dynamic Current Limiter checked (I need that), and Input Limit varied to suit the gensets. The rest I can't seem to be able to post, but I'll try to add in a comment.

Can anyone point me at a possible reason or cure for this? I'm running out of ideas.. Cheers..






MultiPlus Quattro Inverter Chargergenset
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JohnC avatar image JohnC ♦ commented ·

1624778091272.pngMulti charger settings.

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Paul B avatar image Paul B commented ·

1. I have had issue this happen, try turning the power assist tick box off.

Also turning this off also stopped the generator from disconnecting sync for no reason, problem I was having as well, plus this also seemed to be because the low voltage disconnect setting was to close to the gen voltage, like I had it set to 207v volts when the gen was at 227. I dont call this close but anyway it stopped my disconnect issue.

1624787300456.png


2. Another one was using ess and turning the the battery option to optimised without battery life selection


also check your DVCC settings area try turning that off and see if it helps.

bit of a guessing game sorry

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JohnC avatar image JohnC ♦ Paul B commented ·

Thanks @Paul B

I can try this stuff, but in the end I know I can't be without PowerAssist because of the odd 'spiky' ac loads. And I must use DCL to allow the generator(s) to ramp up, and I think PA is part of that..

I won't use ESS because it's offgrid (19m houseboat) and both gensets have plugs. With a bridge-mounted selector switch.

I have tried switching off the SVS part of DVCC, with no effect.

I surely appreciate that it's a guessing game, ha. Some intuition within is telling me that it's 'in' the ac cabling between the gensets and the Multi. Maybe up to 20m of that, mostly inaccessible. But I could bypass it..

All suggestions most welcome and appreciated, and I'll do my best not to make excuses why I can't.. Well, I'll try.. :)

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JohnC avatar image
JohnC answered ·

I found it, results below..

1624942222702.png

I tried many things, even bypassing the wiring with 30m of power cord. The cord fixed it (as I'd suspected), but when I reverted to the original wiring all was still good. Suspect cause.. possibly wire seating on a 63A breaker, or a critter involved with said seating.

Thanks @Paul B and anyone else who might have given this some thought. My faith is restored. Have a good day all, as I will..


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