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ehsab avatar image
ehsab asked

Generator issues with Quattro

Hi,

I've been using a 3-ph Quattro installation (Fronius AC-coupled) for a couple of months now and i love it. It works awesome.
Today i connected a 20kVA genset (Atlas Copco QES) and it didn't quite turned out the way i'd imagined.

The quattros noticed the genset and switched from grid to generator, and i thought all is well.

But almost immediately i noticed intermittent sounds from the quattros, and the amp meter on the genset jumped up and down (not much, but still not steady as i would liked).
Then after about a couple of minutes the quattros disconnect the genset and goes into inverter mode, and then back to genset again, and this process repeats itself.

It's a permanent installation in a house, its a permanent genset, i've got N+PE bridged in the genset, i've got N+PE bridged in my main AC-box and i've got the dynamic ground relay ON in the quattros.

LOM type B is used on both inputs.

Here's a screenshot of the vrm data:


Any thoughts on this problem? Have i overlooked something?

Kind Regards

ehsab

Generator
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1 Answer
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·
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ehsab avatar image ehsab commented ·

No, i was looking for Quattro info, didnt occur to look in Multiplus which lack second ac in.

I’ve read through it now and have a couple of questions.

1. What transfer time do i get of i disable UPS function?

2. Is my best bet to enable dynamic current limiter? Or what would you have started with?


kind regards

Ehsab

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ ehsab commented ·

Hi @ehsab

1. transfer time will be a couple of cycles at most, usually shorter.

2. no, dynamic current limiter is usually only needed for variable speed generators.

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ehsab avatar image ehsab Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

OK, then there's a big risk that my connected equipment will be powercycled, thats not good.

My generator is fixed (1500rpm) AVR (DSR) and of good quality. There shouldn't be any problems powering the (small) load i tested it with.
Any ideas to why it bahaved the way it did?

Kind Regards

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ ehsab commented ·

@ehsab

we cannot guess for you why it disconnected, in the linked document multiple possible reasons are mentioned.

most equipment doesn't flinch from a couple of cycles btw.

so...

did you try disabling LOM?

did you raise the minimum voltage disconnect level? (important for when you stop the generator)

did you -try- without the UPS function?

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ehsab avatar image ehsab Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

@Daniël Boekel (Victron Energy Staff)
I have not been at the site yet, that's why i asked if there were anything in my first post that gave any hint on what could be wrong. Or what i should start with.
As i understands it from other posts, if i disable UPS function it can be up to 1sec of switching time? Is that not true?

My main reason for buying Victron Quattros was the combination of Batteries with fast switching (UPS), generator as a backup to the grid and beeing able to use solar during gridfailures.
I don't want to loose one function to gain another.

There has to be certain parameters that needs to be fulfilled in order to guarantee functions right?
Is there any documentation that mentions theese paramaters, like what differs LOM B from Nothing?
Looking at the VRM data the voltage, frequency or any other paramater was fine when the quattros disabled generator and when inverting.

But i will do some more testing when i'm on site.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ ehsab commented ·

@ehsab

If you're an installer I strongly encourage you to go to a Victron training, now with Covid 19 things are a bit different, but all these things you can learn there (and now maybe online).

https://professional.victronenergy.com/learn/events/

I don't know where you got the 1 second information, but that is of course not true.

also, when LOM is disabled, it still is active but much less sensitive.

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ehsab avatar image ehsab Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

@Daniël Boekel (Victron Energy Staff)

No, i’m not an installer, i would however like to visit your trainings if there ever will be any in the greater copenhagen region.

I’m registered on the professional portal and has completed the interesting courses there.

It was actually a post by you were you state that there can be a gap of up to 1sec with ups function off.

https://community.victronenergy.com/questions/32380/how-long-is-the-transfer-time-with-the-ups-functio.html

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ ehsab commented ·

@ehsab

sharp! well let's consider that a worst-case scenario when the voltage from the generator sags away (brown-out)

when you set the low voltage disconnect high enough, you probably won't have any issues.

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ehsab avatar image ehsab Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

@Daniël Boekel (Victron Energy Staff)

Ok, are you reffering to the UPS function now or the problems i have with the generator?
I´m guessing the UPS function, I will hardly ever use the generator, im grid connected with relative high voltage (242v).
But when SOC reaches under 70% i would like to be able to rely on the generator :)

This is my current configuration:

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ ehsab commented ·

Hi @ehsab

I'd start with disabling LOM on the generator input.

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ehsab avatar image ehsab commented ·

@Daniël Boekel (Victron Energy Staff)

Will enabling Dynamic Current limiter reboot the quattros or will the load stay on?

Kind regards

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