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john2019 avatar image
john2019 asked

What is the Fault current and overload capacity of Victron inverters?

Hi, All

We are designing some off grid system using quattro 10 kVa. However, client need to know

1. Rated Maximum Expected Fault Current (Duration XX Sec) Contribution per Line per Inverter (A)

2. Overload capacity with period. like 150% overload during (xx min) etc

I donot know where I can find them in datasheet and manual

MultiPlus Quattro Inverter Charger
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3 Answers
Johannes Boonstra (Victron Energy Staff) avatar image
Johannes Boonstra (Victron Energy Staff) answered ·

Hello, Fault current is the current to a defective device to ground i assume?, for the inverter that's not different then the normal (overload) power. So the rating is equal there.

If you mean short circuit power, that's limited by the DC circuitry as a low level battery can't supply as much energy as a full one, but its maximal 2 x Inom for 0,5s.


as far as overload, that's also limited as the peak power is and beside this software controlled.

at 20C deg its

2 x Inom - 0,5Sec ( when the load is so high the inverter isn't able to maintain AC voltage as in short circuit situations)

2 x Inom - 2 min when the Ac voltage is as it should be

1,3 x Inom - 30min


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mvtalbot avatar image mvtalbot commented ·

Hi Johannes,

All OK with this answer but what is missing from the specification sheet is the Inom. In the spec sheets, the power output is the same for differing system voltages. For example the 10kVA Quattro spec sheet nominated max power as 20,000W for both system voltages. For the 230 Volt system is Inom = 43.47A? and for the 120Volt system is Inom = 83.33A?.

This is important to understand in relation to protection co ordination. For example a 16A MCCB type C breaker will need about 160A to trip.

So in fault conditions when system voltage is not so relevant is the current from the 10kVA Quattro 166A or 87A?

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Lyndsay Cotton avatar image Lyndsay Cotton commented ·
Hello,

Based on this answer, what would the "duty cycle" be of overloads of this nature. Say 2 x Inom 2min. The unit then goes into overload and trips.

It then restarts after 30sec

I know that a situation like this is far from ideal but could this theoretically continue or is there a "cool down" period

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klim8skeptic avatar image
klim8skeptic answered ·

Overload details Victron Tutorial.

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john2019 avatar image john2019 commented ·

Thanks Klim:

However, this is only half of answer. Client wants to know fault current contributed from inverter, for example like 100A or sth, because they want to set their protection breaker to trip 400ms at fault 100A.

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stretcho avatar image
stretcho answered ·

This is such a frustrating situation. There are a large number of unit sales pending the answer to this question.


The closest information we can find is on the last page of the G59/3-1 Certificate here:

https://www.victronenergy.com/upload/documents/Certificate-G59-3-1-MultiPlus-and-Quattro-3kVA,-5kVA,-8kVA,-10kVA-and-15kVA.pdf


And yet it is extremely unclear with minimal information.

I'm guessing the only way we're really going to get the information is to prove it our selves by potentially blowing a couple of units up?


Is there anyone who can help please?

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Chris Moller avatar image Chris Moller commented ·

I'm struggling with a very similar question. How does a MultiPlus/Quattro behave into a hard short, and hence how long will it take a breaker to trip? If I use a Curve C or D breaker, will I toast the inverter before the breaker trips? As long as the grid is connected, I know I have a kiloamp or more to make the breaker trip quickly, but what is the situation in island mode? (Like @stretcho, I'm reluctant to experiment, in case I blow up my installation.)

To be confident that my installation will survive a sudden hard short in island mode, should I install a special kind of breaker?

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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ Chris Moller commented ·

Hi @Evonet, The inverter itself has built in output short circuit protection - so while not recommended to test it yourself, it has been designed into the unit by Victron, then tested and approved by a 3rd party. A short circuit on output will be detected, and the unit will shut itself down before damage to the inverter.

You can see it listed in the protection section of the product data sheets.

Breakers are of course also recommended to protect all circuits on the output, but not for the protection of the inverter itself.

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