Quattro 15kva battery terminals short during Loadshedding

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leetpro asked Dec 5, '22

Quattro 15kva battery terminals short during Loadshedding

Background : we have blackouts in South-Africa (Loadshedding), power is cut for 2 hours at a time in my town (Nelspruit), depending on the stage between 1 and 4 times per day currently.

I bought the Victron Quattro 15kva with 28 panels, 2 mppts, cerbo gx, color screen, smart shunt and 2 x 10kwh Lithium batteries. Was installed by a Victron accredited installer.

The purchase was made to avoid Loadshedding and not be affected by it.

Between every 3rd and 6th time the inverter will shut down completely, whether my loads are 200, 1200, 2000 or 4000 watts, doen not matter if the batteries are 70, 90 or 100%.

If it's during the daytime it will start up again within 2 minutes if there is sufficient sunlight. During nighttime it wont come back on at all until the grid power is restored.

There is a short on the battery terminals so the batteries goes into protection, It won't turn back on again, even if I turn the unit off and on, only when the grid come back it will turn on.

The installer updated the firmware to the latest version.

He set the cut off voltage to 210v to not follow the grid down for a "brown out"

I cannot replicate the problem by turning of the main grid power, then the inverter switches without issue.

Any help would be appreciated

MultiPlus Quattro Inverter Charger

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Answer 1 · 2022-12-08T17:21:55Z

leetpro answered · Dec 08, 2022 at 05:21 PM

Im really fed up with victron, going to ask my installer for my money back, keeps on saying nothing wrong with the machine , there is also a short on the AC out 1 , video on the next post

whatsapp-video-2022-12-08-at-191451.mp4 (1.3 MiB)

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Answer 2 · 2022-12-08T17:23:38Z

leetpro answered · Dec 08, 2022 at 05:23 PM

Short on AC out 1 , it trips the incoming main breaker

whatsapp-video-2022-12-08-at-191528.mp4 (1.1 MiB)

whatsapp-video-2022-12-08-at-191557.mp4 (2.2 MiB)

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Kevin Windrem commented · Dec 08, 2022 at 05:45 PM

The internal transformer is across the AC output so you can expect a low resistance between these output terminals.

You can also expect low resistance across the battery terminals since there is a large capacitor across these terminals. It would take a very long time for a multimeter in ohms or beeper mode to charge this capacitor.

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leetpro Kevin Windrem commented · Dec 08, 2022 at 08:31 PM

Understandable but the batteries goes into fault mode(Protection mode?) and turns off, when I open the breaker batteries test fine.

The AC now started to trip the main incoming breaker to the house when the grid came back on.

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shaneyake leetpro commented · Dec 09, 2022 at 06:52 AM

Which model battery do you have? Most of the UFO are only rated at 100A so 200A total in your case which would only be 10kva max.

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nickdb ♦♦ shaneyake commented · Dec 09, 2022 at 06:58 AM

He states the powerwall 200A. According to the specs on the site that is 100A per battery, so the pack is undersized for a 15kVA inverter by some margin.

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nickdb ♦♦ commented · Dec 08, 2022 at 06:01 PM

If your installer is really “accredited” they will return to solve your issues.

Those are seriously thin looking wires for a 15kVA, and they seem to have been doubled up to the inverter terminals.

How exactly did they demonstrate their “accreditation”?

It does not look like it conforms to wiring guides.

What batteries are these?

Is there a wiring diagram?

Looks like you need a second opinion on that installation.

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leetpro nickdb ♦♦ commented · Dec 08, 2022 at 08:35 PM

They are an official Victron distributer in my town.

2 x 200ah UFO lithium's https://www.ufo-battery.com/product-category/products/power-wall-battery

The wires that are doubled up comes from the MPPTs

No wiring diagram, no bus bar

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nickdb ♦♦ leetpro commented · Dec 09, 2022 at 05:33 AM

That is still poor wiring, you should not be using the terminals as a bus bar, too many opportunities for bad joins and issues.

The gauge is also far too small.

I would get them back to properly wire that system.

You also have batteries which are not on the supported list, which won't help either.

There are only two recommended installers in the area according to the site: Greenzone and Current Automation..

Wiring unlimited guide:

https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf

Everything you are describing could be a mix of poor installation/configuration and/or battery performance.

Any installer that knows what they are doing would be resolving it for you, and it definitely would not resemble the images you have shared.

It looks more like a DIY job, to be honest.

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Alexandra ♦ commented · Dec 08, 2022 at 06:59 PM

@Leetpro

Battery cables are undersized. For a 15kVa I would expect some fatties there. At least 95mm²x 2 on each positive and negative terminal.

So not installed according to manual. Wonder if the battery undersized...?

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stubbs Alexandra ♦ commented · Dec 08, 2022 at 07:06 PM

I think @Alexandra is correct. The voltage drop has got to be huge under load?

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Answer 3 · 2022-12-09T07:08:35Z

shaneyake answered · Dec 09, 2022 at 07:08 AM

"There is a short on the battery terminals so the batteries goes into protection, It won't turn back on again, even if I turn the unit off and on, only when the grid come back it will turn on."

The multimeter is detecting a short because the capacitors are empty, this is normal.

Quick note on this, this is pretty normal, even with high quality packs like the FreedomWon Lite the battery will trip due to the huge inrush currents. It is recommended to always start the inverters from Grid or Solar if possible. You need to turn inverter off on its little switch and make sure fuses or DC breakers are on, turn the grid on or mppts and wait 30secs or so for the bus to charge up before turning on the batteries. Once everything is on you an turn on the inverter.

But basically the problems you are facing are because the inverter you have is wayyy to big for the batteries you are using. This isn't Victron's fault, this is your installers fault. Cables are also wayyy to small for 15kva as everyone has pointed out.

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leetpro commented · Dec 09, 2022 at 06:56 PM

are 2 x 10kwh lithium batteries too small ?!

the battery cables are 35mm2

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nickdb ♦♦ leetpro commented · Dec 09, 2022 at 06:59 PM

That’s capacity. It is about discharge current. Those batteries are underpowered for your inverter. You would be better off with 4 x 5kWh.

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Alexandra ♦ commented · Dec 09, 2022 at 07:11 PM

@Leetpro

Yes the cabkes are too small. A 15k inverter can draw 312A from the battery. So 2x 95mm² cables for neg and pos each. And a battery bank that can at minimum supply that current. Check the manual it is all there.

35mm² is rated at best for 100A.

Any installer worth their salt would have at least followed the manual.

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img-20221209-wa0000.jpg (82.4 KiB)

leetpro Alexandra ♦ commented · Dec 09, 2022 at 07:36 PM

so I think I might have found the problem, the negative cables are conected to each other.

Only one cable going to inverter

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68ffe525-3210-4278-8368-0bda3fa87267.jpeg (2.8 MiB)

shaneyake leetpro commented · Dec 09, 2022 at 07:46 PM

Wow... Who is the installer? This is shocking and actually unsafe... A complaint should be submitted to Victron to have them removed as an installer.

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Answer 4 · 2022-12-09T19:49:03Z

leetpro answered · Dec 09, 2022 at 07:49 PM

Can these 125A fuses be too small/not letting enough current through?

ce045674-c971-4ab9-aac5-b3f8ea5d6500.jpeg (1.9 MiB)

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nickdb ♦♦ commented · Dec 09, 2022 at 07:52 PM

This community cannot help a bad installation. Contact the listed professionals in your area and get someone experienced to help you.

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andricuss commented · Jan 10, 2023 at 08:56 PM

Hi, could you sort out the problem? I am also from South Africa and have the same problem. 2x 15kva, 4x11.2kw revov batteries, if power goes off at night, sometimes, the batteries trip out, and I have to disconnect the inverters from the batteries, reset them (batteries), and excite one inverter at a time. This takes about 20+ attempts of resetting the battery bank and trying to charge up the capacitors. The first 5 or so only charges up the mppt’s.

Is the battery bank too small? What did you find with your installation? Please contact me 0827713040 if you got an answer for the problem. I have two other similar systems, working 100%, but with larger battery banks. This battery bank can supply 600A, but its almost like it is not enough? Will check cable diameter in the morning, but think it is to specifications.

They are all linked up in 2x lynx distributor boxes, and no shunts or anything. MPPT’s are 2x 450/100’s.

Thank you

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Alexandra ♦ andricuss commented · Jan 12, 2023 at 05:00 AM

@Andricuss

The 4x Revovs are definitely not capable of starting up the inverters. You need a bank capable of 625A continuous.

And the precharge on those revov are not good, so a precharge circuit/procedure/resistor as well.

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andricuss Alexandra ♦ commented · Jan 12, 2023 at 02:00 PM

Thank you Alexandra. I installed another battery yesterday, and things are looking much better. The 5 x11.2kw batteries can now supply 750 amps. Thank you!

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