Another overload has occurred with no obvious reason

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freddyuk asked Dec 6, '19

Another overload has occurred with no obvious reason

Quattro 10k with ESS Grid connected / solar / CCGX.

Previous overload switched off system and due to lock out could not be re started without intervention by un plugging CCGX. Freezer contents lost as we were away.

Just now a year later same overload situation. No warnings - system tripped off.

Overload LED lit. Prior to event Voltage was 48v and load was around 500w. System was discharging as it was after sunset.

At 18.00 voltage dipped from 49.90v to 46.40v and current dipped from -11.40amps to -44.20 amps which was the event. Reset the quattro = 50.20 v and 0.10amps then it reverts to 48v and -7.60 amps which is normal.

No errors or warnings recorded.

The only loads to stress system would be well pump/ freezers no other loads with high inrush.

These loads are running all day without a problem.

So what causes a massive dip in current????

error

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ejrossouw commented · Dec 07, 2019 at 08:48 AM

An overload warning in itself for a short period is not an issue, but what confuses me is that you have an overload if grid connected with ESS. The system should simply pull grid to make up for the shortfall. ESS is not for off-grid. Look at the dynamic cutoff values as likely one was exceed and caused the problem.

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Murray van Graan commented · Dec 07, 2019 at 09:52 AM

I’ve had this issue before, same scenario. It was for some reason the Quattro and grid which for a second drifted frequency causing an overload because of not being in sync. At the time I solved it by changing grid code to other, and of course for safety having an external anti-islanding device.

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ejrossouw Murray van Graan commented · Dec 07, 2019 at 11:25 AM

I somehow still think this example for AGM is closely aligned to the isolated incident you see. Not sure why ESS does not kick in fast enough though. It may just be that two heavy consumers kick in at the same time. I have similar spikes when e.g. turning the kettle or dishwasher on etc. If the Quattro were parallel to grid this may not be a problem, but I suspect for a UPS function you have outputs on AC1.

Since you cannot simulate the problem repeatedly, it will be a challenge. I'd personally make sure all firmwares are up to date as well as do a thorough check of all the connections as oxdation etc can all play a role. What is your battery configuration and settings?

For my RESU10 Li, I this was all set flat to 46V given it can handle a lot without any problem and if the battery has an issue the BMS will take care of it.

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cutoff.jpg (48.0 KiB)

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Answer 1 · 2019-12-06T23:17:26Z

ripper answered · Dec 06, 2019 at 11:17 PM

You seem to have a bigger freezer. A hydrolocked and stalled freezer uses some serious power trying to restart after it has just run and stopped. A freak event maybe. At 46V x 44A that is 2kW and a little high for my expectation but not unreasonable for industrial size freezer I d say. My regular small fridge takes 60W while running and 550W while stalled for comparison. Thats however not enough to kick out a 10kW unit. Does it shut off due to voltage maybe? If the compressor is overheating protected it takes about 20 30 seconds to get it there. If the quattro cant hold the power up for so long there is something wrong with the batteries or adjustments. Would also look for a short power outage or spike in voltage due to no taken off power (loose wire, bad plug or something) before the event where the compressor came to a stop and then the shaking gave it back power or play around with the wiring whether you can get it to stall. Or stall it purposely by unplugging while running and plugging it back in to make sure. Pull it back out if it isnt overheating protected, you fry the motor otherwise.

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Answer 2 · 2019-12-08T05:13:07Z

freddyuk answered · Dec 08, 2019 at 05:13 AM

I am running 3 freezers - 1 fridge freezer + 1 domestic chest + 1 domestic upright. Nothing abnormal except if they all try to start at the same time maybe a problem. Something I considered using a system to prevent that occurrence. Batteries are Aquion so cut off is 36v as they can run 100% DOD. I should check all the plug connections yes in case of loosened terminal but battery system is only 18 months old. Well supply is vulnerable being in a shed but its only standard pump nothing major. Am replacing supply board switch with proper CU fused for Well and outside power/light as currently supplied off main CU board via MCB.

As it has been a year since this happened before it is indeed a challenge to find any problem.

I need to power the CCGX via small solar supply so I can re set remotely as once the CCGX goes down it needs physical intervention on site to break lockout cycle. I have not powered from battery to avoid another cable run and have not cut Pin 7 as this is not ideal. Maybe I should.

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