RCD Tripping randomly

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ispookie666 asked Jul 11, '20

RCD Tripping randomly

I have just about installed Multiplus 48/1200/13 and hooked it up to Li-ion 14s1p batteries.

It has been working perfectly in UPS mode and pass through. To test the capacity, I turned off the mains and the UPS kicked in, I let the system run - till the cut off voltage was reached.

When I turned on the grid/mains - the RCD (on the mains consumer unit) tripped. It did this a few times. I disconnected the load and the same happened (rocker switch in ON position). Then I switched it to charger and it did not trip.

I tried various combinations and unfortunately - the RCD tripping is very random and not reproducible.

AC in comes from the grid

AC out goes to feed a total of 250W (a few pumps)

Any input or help would be appreciated.

MultiPlus Quattro Inverter Charger Generator Grounding

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Guy Stewart (Victron Community Manager) ♦♦ commented · Jul 12, 2020 at 12:43 AM

A system wiring diagram would help with the troubleshooting.

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Answer 1 · 2020-07-22T16:43:18Z

ispookie666 answered · Jul 22, 2020 at 04:43 PM

Wiring diagram - Hope this makes sense

If the low voltage does not kick in(when I don't let the batteries run low) - the system functions perfectly; UPS kicks in and auto transfer works perfectly and the Multiplus charges the battery.

But if the Multiplus shuts down due to low voltage and if the mains come on, the RCD on the main consumer unit trips - If there is AC Load connected. Without any AC Load the RCD does not trip. This situation continues till battery voltage is above low battery voltage alarm.

I have a feeling its something very simple I have over looked.

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Answer 2 · 2020-07-22T22:06:54Z

jwfrary answered · Jul 22, 2020 at 10:06 PM

Can you give us a photo of your mains consumer box.

I’m wondering if you have a rcbo and your not tripping on a ground fault but a current.

Also the obvious check your wiring for chafe, or stray strands at the connections etc.

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Answer 3 · 2020-07-23T04:55:26Z

ispookie666 answered · Jul 23, 2020 at 04:55 AM

The RCD which trips is the one on the left.

As I mentioned in the subsequent post - this only happens when Mains power is restored after Multiplus shuts down due to low battery voltage and with mains pass through.

If it was a fault in wiring, I would have thought the RCD would trip regardless.

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ejrossouw commented · Jul 23, 2020 at 06:05 AM

Is the multi case earthed and how? In a fixed installation, you only need use the earth from the ACIN and ACOUT. Also don't discount a faulty RCD.

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ispookie666 ejrossouw commented · Jul 23, 2020 at 09:13 AM

It is a fixed installation and the Multi case is not earthed(I hope you are referring to the earth pin on the case, at the lower end). The ACIN is earthed as normal from mains, and the ACOUT is wired as required including the earth.

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klim8skeptic ♦ ispookie666 commented · Jul 23, 2020 at 10:37 AM

It is a fixed installation and the Multi case is not earthed

This is not the reality, please be more forthcoming with information.

Neutral to earth leakage will also trip RCD's.

You have a multiplus compact, unplug the output to check downstream ac wiring.

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multuplus-a.jpg (61.2 KiB)

ispookie666 klim8skeptic ♦ commented · Jul 23, 2020 at 01:16 PM

Like I said, the downstream circuit on itself does not trip RCD, it was in this configuration for a few years.

I recently added Multiplus and that's when it tripped (only if the low.battery has caused the inverter to shut down)

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ispookie666 klim8skeptic ♦ commented · Jul 23, 2020 at 01:19 PM

I guess I did not put it correctly. I have not connected the chassis ground to anything.

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ejrossouw ispookie666 commented · Jul 23, 2020 at 10:57 AM

Yes, thank you. I was indeed referring to the case grounding as below.

"- In a fixed installation, uninterruptable grounding can be secured by means of the grounding wire of the AC input. Otherwise the casing must be grounded."

At least we have eliminated one more possibility.

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ispookie666 ejrossouw commented · Jul 23, 2020 at 01:17 PM

I'm sorry.. I did not follow you.

Should I connect the ground to earth of ACIN?

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ejrossouw ispookie666 commented · Jul 23, 2020 at 02:39 PM

If the installation is fixed in e.g. your house, then there is no need to earth the MP case as stated in the manual. In a boat or RV etc, the MP case has to be earthed via the separate earthing terminal on the case. The ACIN and ACOUT however all have to have all three lines (L,N,E) connected. Your connections appear fine.

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ispookie666 ejrossouw commented · Jul 23, 2020 at 06:11 PM

Many thanks for clearing this out.

It is a bit strange that the RCD tripping only happens when mains come back on after the Multiplus has shut down due to low battery voltage

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Answer 4 · 2020-07-23T11:23:28Z

bruces answered · Jul 23, 2020 at 11:23 AM

Please give details of where this install is located?

Country?

House, boat, motorhome etc?

Installed by licensed electrician? (who knows local regs.. MEN etc)

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ispookie666 commented · Jul 23, 2020 at 06:14 PM

Country - United Kingdom

Installation - Home (static)

Installed by myself - the N E L on ACIN and L E N on ACOUT, and the batteries are Yuasa LEV40 14s with a DALY BMS (the tripping occurs even without this BMS).

I have added the Grid code in VE BUS

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klim8skeptic ♦ ispookie666 commented · Jul 23, 2020 at 06:23 PM

You have 2 rcd's, both after the multi output?

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ispookie666 klim8skeptic ♦ commented · Jul 23, 2020 at 08:11 PM

These RCDs are on the consumer unit, the one on the left is the one which trips - which protects the wiring from where the Mulitplus ACIN comes

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klim8skeptic ♦ ispookie666 commented · Jul 31, 2020 at 11:00 AM

The question was "are both rcd's after the multi".

I cant see in the breaker box.................

Where I live, series stacking rcd,s is not good....

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ispookie666 klim8skeptic ♦ commented · Aug 04, 2020 at 05:06 PM

Both RCD's are before the Multiplus. Each RCD controls a different ring. The RCD which is monitoring the ring which supplies the multiplus, trip. I have managed to work around this using two DPDT relay, which suggests it is all to do with Neutral to earth link problem.

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klim8skeptic ♦ ispookie666 commented · Aug 04, 2020 at 06:12 PM

I followed the Easysolar wiring, and used a double pole MCB before the Multi, and a RCBO after the multi.

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easysolar.jpg (57.1 KiB)

Answer 5 · 2020-07-29T20:44:30Z

ispookie666 answered · Jul 29, 2020 at 08:44 PM

I Added a DPDT relay to provide dual source of power to my critical equipment - I was able to consistently create the RCD tripping. When the Multiplus was in the inverter mode and the backup power(Separate mains power) came on but the Multiplus input AC was off, the RCD kept on tripping. I guess this points to N to E linkage problem.

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ispookie666 commented · Jul 30, 2020 at 08:09 PM

Managed to circumvent this by adding a second DPDT relay for the Neutrals (victron output and backup power).

After all this, I believe - when the Victron shuts down following low battery, the N to E link is not broken, causing the RCD to trip when the mains come back.

I'd really appreciate if anyone can verify if this is what is expected.

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Answer 6 · 2021-02-27T22:53:26Z

tedr answered · Feb 27, 2021 at 10:53 PM

Have you tried to disable the "Ground Relay" setting?

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Answer 7 · 2021-05-10T05:23:16Z

Carlos Carvalho answered · May 10, 2021 at 05:23 AM

Still facing this issue? I am having this exact problem

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Answer 8 · 2022-01-12T23:48:55Z

tedr answered · Jan 12, 2022 at 11:48 PM

I have solved the problem with better connected Earth Spike. There was a bad earth connection. Now my neutral and earth are at the same level.

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