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mmx01 avatar image
mmx01 asked

Multiplus II without ESS reporting strange AC consumption (Amps are way off)

Hi All,

Other than this everything else works fine. Today the weather was bad and MP is recharging the battery from the grid. My setup is 2x MP II running in single phase parallel setup. AC ignore is operated via general flag and assistant generator start/stop.



Anyone else is seeing that 214V * 33.1A = 3,53kW? AC loads 1,56kW + battery charger 1,58kW = 3,14kW. Another 136W goes to DC system (I have DC meter) so this is already off by few hundreds. However 214*33,1A = 7083,4W... which would be double what is shown.


I have double checked with shelly energy meter on that phase for AC in and I have real consumption of 3,45kW. Victron seems to be reporting double current however still reporting correct power. I do have external CT clamp on the AC in side connected to the master and it is checked in the configuration settings. It is also doing the same thing on the output with 214*23,6A = 1,56kW... that would be over 5kW. I thought maybe it reports DC amps but that's not adding up either.



Any clue what's going on?

Regards,

M.

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multiplus in parallel
1721678817875.png (44.5 KiB)
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Alexandra avatar image Alexandra ♦ commented ·

@mmx01

Reading around on the forum is it the connection of the ct to the master that sometimes gives grief.

Plugging and unplugging it a few times and making sure the contacts are clean seem to be the solution.

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nickdb avatar image
nickdb answered ·

I have never seen the grid tile amps x V ever add up to actual power consumption, or come close for that matter.

I raised it a few times and got nowhere. And it isn’t related to power factor.

So I just ignore it now.

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chrigu avatar image
chrigu answered ·

Why would it not be related to power factor? Would have been my best guess

Apparent power is 214V x 33.1A = 7083VA

Since its AC, VA is not always equal to W. Its rather almost always not equal.
So the power factor here would be 0.50 (3530W / 7083VA) on the mains side.

The load has a PF of 0.31 at an apparent power of 5050VA (214Vx23.6A) and real power of 1560W

While i wouldnt call this a good PF, it certainly is possible

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mmx01 avatar image mmx01 commented ·

Shelly reports also power factor so that's easy to check. AC out is up to victron but AC in is what shelly is seeing coming in from the grid.


I also lean towards this being not a pf issue unless another device has the same issue with proper pf measurement.


I just forced AC in to top up the batteries.

Victron shows Amps in 42A and 4,54kWh

At the same time shelly reports:

F3 power 4,468.9 W

F3 current 20.35 A

F3 power factor 1.00

F3 voltage 219.6 V

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mmx01 avatar image
mmx01 answered ·

If that was only cosmetics of the dashboard I have few other sources of true consumption to resort to. However this value in particular is important for other system settings, i.e. grid import limit follows exactly this value. You set it to 16A and would expect 16A. However it follows "its" value and not true current value. Consequently it also impacts power assist and everything relying on the current setting of AC in side.

Why? Not sure but I did some trial & error testing. Since I have C32 breaker in the fuse box from DNO (and voltage during peak usage drops to 217V) it should comfortably allow 6,94kW import to recharge the battery and power loads when AC ignore off conditions are met.

So I set the current to 16A (since they tell you for parallel setup true value is x2). That resulted in mere 1,7kW import instead of expected 16Ax2x217 = 6,94kW. I was puzzled by this for few moments and now I am set to 60A import limit. Ironically it comes as 6,5kW of true import per shelly pm and DNO fuse does not trip. C32 would not sustain 60A...

Now the lack of comfort comes from the fact if this is a glitch that will somehow resolve without attention and per definition translates to 60A * 2 = 120A of import limit I've got a problem.

Regards,

M.





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