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deangi avatar image
deangi asked

Multiplus II GX 48/5000 #8 Ground relay test failed

Hi all,

New to 48v, and first time with a Multiplus II.

Just for testing, I have it setup on the bench with a 48v battery.

For TESTING only, I wanted to power on the MP from a standard electrical outlet (UK 13A). I have of course restricted the MP input to 10A to avoid tripping the MCB.

The problem I am getting is the above error, every couple of minutes. Then occasionally "Grid Lost" but nothing is tripping. The MP is in "fault".

I have no loads wired into Outputs 1 or 2 on the MP.

Firmware is uptodate

Any ideas?

Thanks

Dean

Multiplus-II
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2 Answers
Alexandra avatar image
Alexandra answered ·

@DeanGi

Error #8 is referring to the internal ground relay. It usually closes when the grid is 'lost' making its own internal earth neutral connect. Maybe there is bad contact in the plug you are using for the jerry rig?

Do you have a grid code set? It may have something to do with that and the fact it is not installed.

Does the case of the MP become live during this time?

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deangi avatar image deangi commented ·

Thanks for that. I will change the cable and plug.

Yes, grid code set, and LOM. It isn't losing grid connection though, otherwise it would power itself down.

I haven't checked the case.

Thanks


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Alexandra avatar image Alexandra ♦ deangi commented ·

Check if there is continuity between L and N on the incoming.

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deangi avatar image deangi Alexandra ♦ commented ·
There is no continuity between L and N.
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Alexandra avatar image Alexandra ♦ deangi commented ·

@DeanGi

Sorry I meant Neutral and earth. My brain has definitely embraced the holiday.

The block diagram is helpful. The ground relay is the one that closes or opens depending on whether you are connected to grid or not.

You should hear relays clicking when plugging and unplugging the system. If you dont then they are not working, or the grid power is not being accepted.

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deangi avatar image
deangi answered ·

Morning, sorry for the delay. So, this morning I thought I would check the voltage at the battery terminals as I realised the MP was switching off when mains was removed. About 5v!. Realised I had a bad connection on the neg lead. All corrected and the relay problem seems to have stopped. Does this make any sense?



Now need to check all parameters as the charging is only about .2amps!


Thanks for all your help so far.



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