question

rns avatar image
rns asked

UPS connected to multiplus II starts event that multiplus is working

This weekend I saw my Trust UPS connected on AC OUT 1, switching to UPS mode a few times. The UPS switched back to AC withing the same minute.

What could be the cause for this ?

Multiplus-IIups
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
Alexandra avatar image
Alexandra answered ·

@rns

The ups has a tighter tolerance for power fluctuations. The multiplus has a huge inductor in it as well, when some loads switch on the interaction between the power incoming, loads and that inductor would be enough to triggger the ups.

The victron accepts a wider range depending on how it is set up.

One way to prevent the power dip is to increase battery cable size to the inverter.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

rns avatar image
rns answered ·

I have two batteries 14.3Kwh 280AH in parallel each with 50mm2 cables so losses should be very limited. Cable length is around 1.2 meter to a busbar.

Length from the busbar to the multiplus is ardound 20cm and is also 50mm2.

What I do see is that the battery changed from charging to discharging at that moment so the inverter also had to change from charging to inverting.

The data I have shows only spikes of 400w discharging . Few seconds before it was charging at around 600w.


Both values are per battery so from 1200w charging to 800w discharging.


Strange thing is that I had the ups disconnects at 12:07, 12:19, 12:40 and 13:45

So the disconnects even don't match with spikes and I didn't have issues after 13:45 even that I had more spikes like in the picture below after that time.

1662411773276.png

1662411792641.png


1662411773276.png (58.0 KiB)
1662411792641.png (23.6 KiB)
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources