question

russ avatar image
russ asked

Overvoltage alarm

G'day

Multiplus II 48/5000

ESS

Pylontech 3000x8

4.5kw ac coupled pv on ac out

Now summer has arrived,{Australia} I'm seeing overvoltage alarms from the pylontech, and the dc bus voltage seems to be hitting 56v.

Fully charged, on grid and feeding in.

The ac grid is on the higher side, at about 245v but within spec.

This has happened 3 times now, while I am away so house is relatively low load.

A) what could be causing this?

B) what if anything can I do remotely?

C) what can I do on my system to prevent?

If I was home I could possibly increase load, or shut off solar, but neither are ideal as I'm not always at home, and shutting off solar may cost me..

Thanks



ESSPylontech
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3 Answers
nickdb avatar image
nickdb answered ·

Go back to basics, run through the victron/pylon guide to make sure everything is set right, including the “manual” settings on inverters/mppts etc.

Check all the packs are being seen by the GX.

Then get a meter and check the readings at the inverter/mppt/battery terminals to make sure there isn’t voltage drop at any point - if there is, check for loose/bad connections.

PV inverters add another variable, so best to review that configuration as well.

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ponzoa avatar image
ponzoa answered ·

I'm having a similar issue with a similar setup and have detected it is caused by a grid disconnect. That is, grid overvoltage, Multi disconnects from grid (correct behaviour) but the Fronius and MPPT take time to ramp down so the excess power goes to the batteries causing an overvoltage alarm.

I just asked a question regarding this to find out how to solve without changing grid code (if possible).

post is here https://community.victronenergy.com/questions/210312/grid-overvoltage-causing-issues-with-batteries-ess.html

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Rob Duthie avatar image
Rob Duthie answered ·

Hi

Note you could have a bad cell in the Pylontechs, Had this before a on a couple of site. Need to interogate the Pylontech batteries with there software and RS232 connection lead.

If the DC bus is hitting 56v has the ESS setting have the correct setup?

Regards

Rob D

NZ

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