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jserra avatar image
jserra asked

PowerAssist - Maximum AC-OUT current

Hi,

Sorry if this has already been asked.

Going trough the Multiplus II manual, I cannot find a clear information about the maximum output current supported by the 10kVA/230 model in PowerAssist mode.

The manual:

AC-out-1 The AC output cable can be connected directly to the terminal block ‘AC-out’. From left to right: “N” (neutral), “PE” (earth) and “L” (phase) With its PowerAssist feature the inverter/charger can add up to 3 kVA (that is 3000 / 230 = 13 A) to the output during periods of peak power requirement. Together with a maximum input current of 32 A, this means that the output can supply up to 32 + 13 = 45 A. An earth leakage circuit breaker and a fuse or circuit breaker rated to support the expected load must be included in series with the output, and the cable cross-section must be sized accordingly.

Is this only for the 3kVA/230 model? What are the values for the 10kVA/230 model?

Can I assume that the 10kVA model can handle 50A (AC Input) + 43A (Inverter) on the AC-OUT-1 and AC-OUT-2?


Thanks!

Multiplus-II
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4 Answers
delf67 avatar image
delf67 answered ·

It took about 5 seconds to do a google search and find the datasheet for a Multiplus 2 10kVA.

100A maximum AC input current + 43A (10000/230 powerassist) = 143A Total

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jserra avatar image jserra commented ·

Thanks for the help.

After more digging I still cannot find a manual with that information. Can you please share the link?

Please note that what i'm looking for is a formal Victron manual/datasheet with that information clearly stated. The current datasheet doesn't have that information.

I'm looking here: MultiPlus-II - Victron Energy

MultiPlus-II 3kVA - 15kVA 230V

and here: MultiPlus-II - Victron Energy

MultiPlus-II 230V (PDF)

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delf67 avatar image
delf67 answered ·

Hi,

I'm not really sure what you are expecting to see?

The current datasheet quite clearly states that the maximum ac input and changeover relay are rated at 100A. The same datasheet also states that the inverter has a continuous rated power output (at 25deg C) of 10000VA. At a power factor of 1 (ie a completely resistive load) and an output voltage of 230V, that equals 43.48A (10000/230), therefore the unit is capable of passing through 100A with powerassist adding an additional 43.48A.

No, the datasheet does not say in words what I have said above, it gives you the relevant figures to be able to calculate it.

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jserra avatar image
jserra answered ·

Hi,

First, thanks for taking the time to help me. I'm looking at these devices for the first time.

Yes, we can make an assumption/calculate with the values on the datasheet. I don't work with assumptions.

In the "Multiplus II manual", which is valid for all the models, this is what is stated:

AC-out-1 The AC output cable can be connected directly to the terminal block ‘AC-out’. From left to right: “N” (neutral), “PE” (earth) and “L” (phase) With its PowerAssist feature the inverter/charger can add up to 3 kVA (that is 3000 / 230 = 13 A) to the output during periods of peak power requirement. Together with a maximum input current of 32 A, this means that the output can supply up to 32 + 13 = 45 A. An earth leakage circuit breaker and a fuse or circuit breaker rated to support the expected load must be included in series with the output, and the cable cross-section must be sized accordingly.

Yes, we can make an assumption that this is only for the 3kVA model, and that for the other models we just replace the numbers. But in the end, it is an assumption, and, if for some reason something goes wrong, the liability is on our side. That's why I don't work with assumptions.

I think something is missing in the documentation.


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delf67 avatar image delf67 commented ·

Sorry, but you are completely wrong. There are no assumptions made here.

There is a calculation performed using a 100% accepted electrical formula with stated specification figures provided by the manufacturer on the product's datasheet. That is not an assumption.

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Kevin Windrem avatar image
Kevin Windrem answered ·

Yes, the documentation is in error here. But as others have said, it's easy to use the formulas provided for the 3000 VA model for other models.

Relying on full shore power plus power assist means that the inverter will overload if shore power is missing unless you shed some loads when shore power disappears. Models with two AC outputs can help manage the loads since the second output turns off with loss of shore power. However, the second AC output is often rated for less current than the main one. The data sheet lists the max AC 2 output current.

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sharpener avatar image sharpener commented ·

I am with @jserra on this one. The documentation ought to be far more explicit about the various power ratings.

If you find the video on the topic it is also stated there that the inverter will stand a 100% overload for ?30 secs ?2 mins (along with some other stuff about motor starting). But this is based on the continuous rating which in turn is 80% of the nameplate (itself a cause of confusion).


So in my case with a Multi 48/5000/70-50 it will be able to output 50A passthru plus (2 x 0.8 x 5000 / 230) i.e. nearly 85A for a short time. Not exactly a straightforward calculation which is why I would rather see all this key material clearly set out in the data sheet.

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delf67 avatar image delf67 commented ·
I disagree that the documentation is "in error".

Victron give an example of the powerassist calculation for a 3000VA unit with a 32A ac in and then give the specifications for all other units, allowing people to substitute 5000/ 8000/ 10000 or 15000 for 3000VA for power output and 50 or 100 for 32A in the maximum ac in, and come up with the correct figure for the unit they are interested in.

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jserra avatar image jserra delf67 commented ·

Where in the manual Victron states that the info or for the 3kVA unit?

Again, this is what is stated:

AC-out-1 The AC output cable can be connected directly to the terminal block ‘AC-out’. From left to right: “N” (neutral), “PE” (earth) and “L” (phase) With its PowerAssist feature the inverter/charger can add up to 3 kVA (that is 3000 / 230 = 13 A) to the output during periods of peak power requirement. Together with a maximum input current of 32 A, this means that the output can supply up to 32 + 13 = 45 A. An earth leakage circuit breaker and a fuse or circuit breaker rated to support the expected load must be included in series with the output, and the cable cross-section must be sized accordingly.

The manual does not refer any unit in particular, so, this statement is valid for all the units.


Please note what they state about AC-IN:

AC-In The AC input cable can be connected to the terminal block ‘AC–in’. From left to right: “N” (neutral), “PE” (earth) and “L” (phase) The AC input must be protected by a fuse or magnetic circuit breaker rated at 32 A (for 3 kVA model), 50 A (for 5 kVA model) and 100 A (for 8 kVA and 10 kVA model) or less, and the cable cross-section must be sized accordingly. If the input AC supply is rated at a lower value, the fuse or magnetic circuit breaker should be downsized accordingly.

Here they state the currents for each model. Why they do it here and don't do it in the AC-OUT-1?


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delf67 avatar image delf67 jserra commented ·

I'm assuming that either English isn't your first language or you're just deliberately misinterpreting the documentation.

"Where in the manual Victron states that the info or for the 3kVA unit?"

the inverter/charger can add up to 3 kVA.....Together with a maximum input current of 32 A

"circuit breaker rated at 32 A (for 3 kVA model)"


"The manual does not refer any unit in particular, so, this statement is valid for all the units." - What a ridiculous thing to say, it's obviously not valid for all units. If the input & transfer switch for 8 & 10kVA models is100A how would the output only be 45A?



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sharpener avatar image sharpener delf67 commented ·

Your answer still doesn't take account of the short term rating of the inverter.

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