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tom-galletti asked

MultiPlus rejecting generator power

I've got a MultiPlus set to charge a bank of 24V batteries (no inverter required).

In accordance with this: https://www.victronenergy.com/live/multiplus_faq

My charge controller is 1600VA, and my generator is 4.5kVA and AVR so should be fine. My generator is running fine, with no stuttering or difficulty starting.

These are the details for the inverter/charger:

1628669498277.png

Despite all this, the MultiPlus doesn't accept the power coming in from the generator. There are no alarms reported:

1628669384652.png

But the charger reads "Fault":

1628669548074.png

And so the AC in claims it's disconnected and at 0W:

1628669576600.png

The same is true when I move the switch to Inverting, only it claims there is no fault:

1628669644678.png1628669680522.png

It seems when the generator runs, the batteries jump temporarily up to 28V, but then fall immediately back to about 22V, so haven't actually been charged...

1628670149513.png

Any suggestions would be greatly appreciated.

Multiplus-IIGeneratorfault
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seb71 avatar image seb71 commented ·
Upload here your Multiplus configuration file.
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harold avatar image harold commented ·
Check your settings in VE.Config, suggestions:
  • Switch of the UPS function
  • and/or
  • Switch on accept wide range
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tom-galletti avatar image tom-galletti harold commented ·
Unless I'm wrong I can't access VE.Config remotely and I need to buy a proprietary adapter for it?

I will test these settings as soon as I'm next at site.


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harold avatar image harold tom-galletti commented ·
If your site is connected to VRM you can download the settings file, change the settings and upload it again
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seb71 avatar image seb71 tom-galletti commented ·
How you configured your Multiplus, in that case?
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JohnC avatar image JohnC ♦ seb71 commented ·
I suspect all is still at default. As the 16A Input Current Limit, which is the first thing I'd change (from the GX), like way down to maybe 3A for testing..
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tom-galletti avatar image tom-galletti JohnC ♦ commented ·

Intuitivelly I assumed "current limit" was to avoid overloading my generator. My generator can put out about 18A at 240V so what's the logic behind reducing the input limit?

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JohnC avatar image JohnC ♦ tom-galletti commented ·
@Tom Galletti

I did say for 'testing'. Many gensets will distort power at high amps, and most can't handle an instantaneous demand. There's a setting in the Multi called Dynamic Current Limiter, and I expect you'll need to use it.

The Multi is picky about bad power, and the rejection symptoms are as you describe. I have 2x gensets, and when I change over I need to send new settings. (Thank you VRM).

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tom-galletti avatar image tom-galletti seb71 commented ·
My MultiPlus was only configured using the Cerbo GX. The site is connected to the VRM but doesn't seem to come online after a low voltage event until I powercycle the gateway (a separate issue...).


When I next visit I'll powercycle the gateway and download the settings file from the VRM. Will reupload the config file to both the MultiPlus and this forum with UPS function disabled and Wide Range acceptance enabled.


Cheers.


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seb71 avatar image seb71 tom-galletti commented ·
How is your Cerbo GX accessing the Internet? Via Wi-Fi or via LAN cable?

Which firmware version it has?


One reason AC In (from generator) is rejected could be the 52Hz frequency - depending on how your Multiplus is configured. This is why it is very difficult to investigate without even knowing how it is configured.


A Mk3-USB interface (and VE Configure 3 software running on a PC) might also give you some clues in real-time.
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Paul B answered ·

Also if the above suggestions dont work I would upgrade the firmware from 430 to the latest 482 on the multiplus

Also if it still does not work then TRY turning off power assist. I have had to do this on one of my sites that kept loosing generator sync and that fixed the issue.
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Paul B avatar image Paul B commented ·

You also Mention this "It seems when the generator runs, the batteries jump temporarily up to 28V, but then fall immediately back to about 22V, so haven't actually been charged... "

You may find that the battery voltage is going two high and thus the charger is going into fault mode and turning off (just a guess). So try another battery and test this possible issue. as The charger maybe sensing that there is NO battery there because its SO flat - or something silly like that.


if it is jumping to 28 so quickly it could sort of points to a battery fault as well. (ie it may need a very low trickel charge. Also you dont mention the battery type, If its lithium then the BMS maybe opening because of a internal battery issue.

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tom-galletti avatar image tom-galletti Paul B commented ·
My batteries are all lead acid car batteries - I'll take a couple of new ones down and see if they're the issue, but I've got 8 of them so would be dissapointing if they're all dead...
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Related Resources

MultiPlus-II Product page 

MultiPlus-II Manual

Multiplus-II GX Online Manual

MultiPlus-II 230V Datasheet 

VE.Bus Error codes

Additional resources still need to be added for this topic

MultiPlus Generator FAQ

GX - Generator auto start/stop

Automatic Generator start/stop

 Hybrid Generators

Virtual switch - Generator start/stop

Faults with Victron equipment are best discussed directly with your dealer - this can be formalised with this support request form.