Multiplus 12/1600/70 negative AC Out power consumption

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enodev asked Sep 20, '21

Multiplus 12/1600/70 negative AC Out power consumption

Hi guys,

one more puzzling question about my new Multiplus 12/1600/70.

if you look closely at the Victron Connect screenshot below, the AC out is drawing -4W, that is minus four wats. This is without any AC load. If I turn on the coffee maker, the Victron Connect correctly reports around 1000W, that is plus thousand watts.

But sitting idle, there is minus 4 watts.

that sounds like nonsense, right? Firmware 485. Possibly related to my other question here https://community.victronenergy.com/questions/101904/aes-search-mode-mode-not-starting-in-low-watt-sett.html....

Any idea what is going on? How could this even happen?

thanks

Martin

multiplus ve.bus

23848-img-2037.jpeg (4.3 MiB)

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kevgermany ♦♦ commented · Sep 27, 2021 at 08:26 PM

Just upgraded mine to latest firmware, introduced the same issue and stopped it going into low power mode.

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kevgermany ♦♦ kevgermany ♦♦ commented · Sep 28, 2021 at 07:27 PM

Thinking more about this, I think the report is showing the inverter internal consumption as an AC load.

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pmikep commented · Nov 05, 2021 at 02:07 AM

I reported similar on January 28, 2021. (Didn't my post show up when you searched for this issue before posting?)

Anyway, it appears to be noise from an internal sensor picking up current from the inverter. (Eddy currents? Radiated?)

I recently did some more testing on this, and recorded a bunch of video. I'll plan to edit it and post a link here and in my original Report, FWIW.

But it might not be worth anything because from what I can tell, it appears to be hardware related. Meaning that it would take a hardware revision to fix properly. But I expect that Victron is done revising the Mulitplus now that the Mulitplus II is in production.

(In my original Report, where I didn't realize that 120 VAC was passing through to L1 even when in "Charger Only", I suggested that this problem could fixed/hidden by software. But I was wrong.)

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Modifications Space

Node Red Space

Answer 1 · 2021-11-04T18:43:55Z

Mike Dorsett answered · Nov 04, 2021 at 06:43 PM

At low power levels, you will have a capacative current flowing in the AC circuit:this will be causing a small offset in the AC /Dc converter feeding the ADC for the AC current sensing.This will modify the device's zero setting value. With a large load, this small offset is swamped by the main resistive current flowing in the coffee maker's heater.If you disconnect the AC out cable from the inverter, you should see the no load ac power go to zero.

Don't worry about this small offset.

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enodev commented · Nov 05, 2021 at 08:18 AM

I see -4W all the time when there is no load, even when the cables are disconnected, that is what was puzzling, but sound like your answer may explain it. Thanks a lot for your time!

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