Shore power current limit bug

Q&A and troubleshooting
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1

I have a Victron Quattro and I’m currently hooked up to Shore power (residential 15 amp service).

when running my two mini splits and other devices like TV I’m pulling 1360 W from the inverter however, my shore power input has dropped to 760 W.

I have the current limiter set to 15 amp. If I change it to 20 amp, it will draw 1800 W and if I reduce the load by turning off one of the air conditioners, it will also draw over 1300 W from shore power

So why is it only drawing half the available power from shore power when I’m close to or slightly above the threshold for the current limit. In my opinion, it should be assisting to get that last few percent from the batteries, not take 50% from the batteries and deplete them so that when I leave, I’ve only got half my battery capacity

2

Probably those mini-splits have a weird power factor. Check the product labels.

3

Makes no sense. I see the load and I put W. What had the device got to do with reducing g shore power by 50%

4

Sorry, maybe a degree in electrical engineering would help understanding :wink:

5

If you have voltage drop from shore power it will mess with things.

While in simple terms Watts is Volts x Amps. Unfortunately it is not simple.There are other factors that make weird things happen.

But if anything simple it will be volt drop over cabling, either from shore to to loads.

How is the system programmed other wise? Is weak AC checked?

6

The inverter has a minimum threshold for inverted power while using power assist. If power assist is needed, this minimum threshold must be provided by the inverter and the remainder of the load will be powered from shore. So for example if your current limit is 1600 watts and your load is 1600 watts, the inverter will supply the minimum threshold (this varies from model to model) let’s say 750 watts and the rest comes from shore. The inverter also keeps a small buffer so if the shore limit is set to 15 amps, it will keep you under, it won’t take you right up to the limit.

1 Like
7

If it was voltage drop or weak ac how does it go up to 1800w when I set limit to 20A?

8

@MarkCHI the load may change the phase of the voltage and the current. For instance an inductive load like a motor will make the current lag behind the voltage by a certain phase angle. This “power factor” can make the load look small in real power but make the current higher than you may expect in practice. The result is you see a small load in Watts but the current is higher than that load suggests because of the change in phase angle. The cosine of the angle is the Power Factor. So a power factor of say 0.8 has a phase angle between voltage and current of 64 degrees which is quite a bit.

Power factor can make the simple formula for power W= V x A not work out in practice if the power factor is appreciable.

I hope this helps,

Trevor

9

I was trying to work out why it is not recharging. Sometimes happens if there is a voltage drop and weak ac is checked.
Both Terrence and Derrick have also highlighted reasons all if which could be part of the combination causig what you see.
Of course we dont know anything about the electical set up or how the inverter is programmed. All we know is it is not doing what you want it to do.