Quattro 8000 high leakage current

Question

question

lucasnowak asked May 3, '23

Hi,

We've got a boat system with 3 parallel Quattro 24/8000 and 40kWh batteries running as single phase.

When we power it from shore and Quattro clutches, the shore side RCD trips.

I've measured the leak current and it is 48mA in total for all 3 devices.

When we switch it off using Cerbo (physical switch stays on ON), then leak current stays at 8mA.

I'd assume 48mA is quite high for a leakage current, but correct me if I'm wrong.

To advance the answer, yes, the output breakers are opened so we only measure Quattro leak current, not the devices behind it.

Earth-relay is set as ON.

Cables are brand new, so I wouldn't expect that to be the cause. Megger test showed no issues.

Any ideas where should we look for the fault?

KR,

Lucas

MultiPlus Quattro Inverter Charger inverter current draw

2 |3000

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Answer 1 · 2023-05-04T11:53:05Z

lucasnowak answered · May 04, 2023 at 11:53 AM

Hi, got an update on the case.

It looks our Sonel CMP-200 was giving incorrect values. Now got a better one which gives more correct measurements.

In total the leakage between 3x Quattro 24/8000 is 10mA.

Still, it's quite significant since most of the RCDs are 30mA and activate in a "grey-zone" of 20-30mA.

I've noticed that even with Quattros switches OFF on the front button and having Neutral connected, the leak is 10mA in total - 3,5mA per unit.

Is that a normal behaviour for those devices?

I know 3,5mA of leak is not that significant, but having a few units in parallel starts creating an issue.

Another way to tackle it is, if there are any ways of minimising that leak current setting-wise.

Looking forward for any ideas.

KR,

Lucas

2 |3000

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