question

wolley avatar image
wolley asked

Multiplus II not startign my compressor

Dear Victron Community

I have x2 Multiplus 3000kVA inverters powering my home. I am mostly off-grid except for a few requirements still. I (please) need help with the following

I have a compressor, that starts (under load) with the grid connected, but fails to start off-grid (withno other loads present)

* 3HP, 220V / 50Hz

* Rated current 13.7A with a 200/40uF Cap

Will a slightly larger Cap help or will this burn by compressort motor starter windings?

Battery is x4 10kVA LiFePO4 systems


Kind regards

Wolley

Multiplus-II
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

13.7A at 230V are 3150W.

The 3000VA MultiPlus has a continuous power of 2400W at 25°C.

Also a motor needs 5-10 times more power to start.

So the 3000VA Multi is way too small for your use.

2 comments
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seb71 avatar image seb71 commented ·
He wrote that he has two 3000VA Multiplus inverters (presumably in parallel). It might still not be enough, though.
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Matthias Lange - DE avatar image Matthias Lange - DE ♦ seb71 commented ·

Oh, you are correct I didn't see that, maybe it's time to go to bed. :D

But as you said, I also think this is still not enough.

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Kevin Windrem avatar image
Kevin Windrem answered ·

A soft start would probably help if one can be fitted to your compressor motor

You may also not have enough battery current capacity to handle the surge. This would probably be indicated by a low battery alarm

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snoobler avatar image
snoobler answered ·

Get an clamp ammeter with an INRUSH function and see what the inrush/surge is. I would expect it's around 55A+, and that's why you can't start it.

I have 2X quattro 5000, and they would be able to handle it, but well into their surge rating.



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