question

nick5000 avatar image
nick5000 asked

Multi RS - Victron app AC output showing strange numbers

In the Victron app I sometimes get -6W or so coming FROM the AC out1 (going into batteries) when no load is connected the the output. Tried with both the Multi grounded and ungrounded, this didn’t make any difference. It also didn’t make any difference when I switched of the breakers that the AC out is connected to (so I don't understand where this 6W was coming from).

I borrowed a generator to test the AC input going into the inverter. The (old) generator outputted 190V and 57hz according to the Victron app. No current were flowing into the batteries. Was this probably because of the incorrect hz? The app settings says low voltage cut of 180V and start at 187V, so 190V should be enough according to that setting.

I managed to get it to take in some current by disabling ground checks etc. Then I saw 150W coming from the AC input, but also 150W going out from the inverter AC out even when the inverter function was turned off (set to charger only) - these input and output numbers were 100% following each other. I turned it off quickly as I thought it must be bad to have 150W “disappear” somewhere. How can there be power out from AC (inverter) when the inverter is turned off?


VictronConnectMulti RS
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1 Answer
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @nick5000,

It’s pretty normal to have a few “phantom” watts, <10W.

The way the inverter measures current is less accurate at the low end of its range, it has to measure into the 10000’s of watts, and there can be fidelity compromise at the single digit watts range.

There is a balance between filtering these out to zero, but then the downside is when there is a very small load connected it gets filtered.

It’s nothing to worry about though.

Regarding the generator, a 190V 57 hz output likely has other sine wave deformation as well, these can also cause issues with how the current is detected.

There is no harm imo from trying to connect, but I am not surprised it doesn’t cleanly connect and synchronise. More insight into this requires an oscilloscope and a generator service to try and get the waveform closer to the Multis.

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