question

ben avatar image
ben asked

Shore input current limits with paralleled Quattros

I'm considering adding a second Quattro to my system in a parallel, single-phase configuration.

If I do this, will there still be an "Input Current Limit" option? Will it just be a single value that is replicated to both units? Or a single value divided in two to send to both units? Or, will I see two independent Current Limit options?

inverter current draw
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2 Answers
boekel avatar image
boekel answered ·

You set the current per phase, so two unit's in parallel (on one phase) will automatically divide the current you set.

(at least that's how it works with the remote control panels, so I'd say it's the same with a Venus device)

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ben avatar image ben ♦ commented ·

So, do you think it will simply enforce the per-device minimum times 2?

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boekel avatar image boekel ♦ ben ♦ commented ·

yes, and if you set it to zero it will switch to inverter mode.

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ben avatar image ben ♦ boekel ♦ commented ·

Okay, thanks for that. On another forum, someone is reporting that the behavior is different, so I guess I should wait and see if Victron has an official answer before I order.

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jacko avatar image jacko ben ♦ commented ·

The current limit you set on a parralell system is doubled, if you set 30amps ac1 input limit on both units using ve bus configure then ve configure, the total amount would be 60amps input limit

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ben avatar image ben ♦ jacko commented ·

Thank you. That seems straightforward.

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boekel avatar image boekel ♦ ben ♦ commented ·

I should have asked this question earlier:

Are you using a Remote Control Panel? or Venus?

Indeed the current you set in VE.config is per unit.
The current limit you set on a remote panel is the total current.

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ben avatar image ben ♦ boekel ♦ commented ·

I'm using a Venus, and that's the current I'm interested in.

So, if I'm paralleling two units on modern firmware with shore current minima of 7.5A and 7.5A, you're telling me that the Venus will force the value to 15A if I try to set it lower. I think. :)

I have a firsthand report of someone with two of these Quattros paralleled who seems to be able to set the value as low as 11.5A in Venus.

I am trying to figure out what the real answer is, because I get in a lot of situations where the shore supply is very small.

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boekel avatar image boekel ♦ ben ♦ commented ·

It's not the Venus that is the limiting factor, but the Quattro's.

I don't know if the minimum current is lower when paralleling units, @Johannes Boonstra (Victron Energy Staff) might know?

If you're struggling with input current limitations, also have a look at this:
https://community.victronenergy.com/questions/8933/example-of-using-assistants-partial-off-grid-boat.html

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Johannes Boonstra (Victron Energy Staff) avatar image
Johannes Boonstra (Victron Energy Staff) answered ·

Hello,

The answers given is correct, if the minimal input current is 7,5A the parallel system will have a 15A as minimal setting ( and the current drawn from the shore will be about 80% of this so you will see 12A there). But when the PowerAssist function is disabled you can co lower the this (to 1A theoraticly)

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ben avatar image ben ♦ commented ·

Okay, thank you regarding the answer to my question.

Also, understood regarding the "unlimited minimum" when not PowerAssisting.

Question: why would the shore show 80% of the specified minimum? That's not what I observe today with my Quattros. Maybe I am misunderstanding what I am seeing.

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