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rl78 avatar image
rl78 asked

ESS 3phase Grounding Relay; 2nd try this time English

Hello Victron community,


Problem VE Error 8 Grounding Relay with ESS 3 phases

This is the 2nd try, this time in English


I am currently building an ESS 3 phase system.

In principle, everything works, but if the 3 neutrals from AC out 2 (emergency power) are connected to the star point (center of Y ) the system fails with error 8 (Groundig Relay) The Star ponit (center of Y) does not have a connection to PE

The system Is wired according to the scheme for 3 phases, AC out 1 is not used.

AC out 2 is intended to provide 3-phase emergency power / stand-alone grid.

Each AC IN has PE, each AC Out2 has PE, PE screw on each device also connected

Location is Germany.

All Multiplus are FW 2624494.

GX Device is on FW v2.84

ESS assistant etc loaded on each Multiplus via MK2/3 adapter and via VE.Bus quick configure.

Identical configuration.

The devices are:

Multiplus2 48V / 5000 GX PMP482506000 SN HQ2041VEN8P as master

Multiplus2 48V/5000 PMP482505010 SN HQ2139PGTAV

Multiplus2 48V / 5000 PMP482505010 SN HQ2139PHEPY

Battery pack are 8 Pylontech 2000

If the 3 neutral wires are not connected, the system works without error


I asked for help form the dealer but the answer was: Please read the manual. I can't help you with 3 phases...


Does somebody has any idea ?


Many thanks for helping out.


Ralf



ESS3 phase
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6 Answers
Alexandra avatar image
Alexandra answered ·

@RL78

Have you looked at the VE bus error manual?

Error #8.

With an error like this I would start checking wiring, particularly the ground neutral since they are tied. Or if somewhere someone has mixed a L and N.

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Kevin Windrem avatar image
Kevin Windrem answered ·

From all information I see on-line, the AC 2 output is for non-essential loads and is only active when the grid is connected (not inverting). AC 1 output is the main output and is active while inverting. AC 1 output use the one I believe you should be using for your emergency power loads.

I don't know for sure this is the cause of your error but I'd switch the loads to the AC 1 outputs for proper/expected operation and see of that clears the fault.

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rl78 avatar image
rl78 answered ·

@Kevin Windrem

Sorry my fault, Output AC1 is of course used.


@ Alexandra

Yes I did read the error codes in the VE manual.

Error 8 is failed grounding relay test. In This case it looks like the unit is expecting an open connection, but detects a connection N to PE.

There is no connection between N an PE wired.

I did some tests tonight. It seems that I can connect the multi L2 and L3 neutrals without fail. After the Relay test I conneceted the N from L1 Multi also.


Till now it is working. I'll verify this next evening again.


Is it possiple that the Multi (GX) L1 is an older HW version ?

It seems to me like a timing problem when grounding relay test. (Multi L1 testing for no conn and one of the others coses the connection for testing...)


Any idea how to get rid of this problem ?


Does anyone know how, when and how often the grounding relay tets is done ?

Can I disable it in ESS german settings (Int NA protection setting) and use an external relay?


Good night for now, and thanks for your thoughts so far



Ralf





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Alexandra avatar image Alexandra ♦ commented ·

@RL78

It is my understanding that the ground relay is only engaged when there is no grid to keep RCDs and other safety systems working.

In all my setups N+ E are connected/ bonded in the DB before the inverter but not after.

Disconnect all wiring for loads and connect AC in (but do not switch on).

Check your incoming wiring with your grid standard (it is possible with a grid code programmed it is not meeting the standard) against recommended for Victron units installed.

Connect to the Grid and see of it starts charging.

If you are still getting the error the problem is not downstream. A other possiblity is the unit, if you are still having the issues, then try swap units around and reconfigure. Start the test again.

There is also this video.

https://m.youtube.com/watch?v=OU4x5CqiJdw

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rl78 avatar image rl78 Alexandra ♦ commented ·

Yes the grounding relay is used for "earthing" the neutral so that RCDs or (in this case small) fuses oer MCBs carn trip if there is a faulty device, and the current will flow to PE.


Normaly in a TN-S wireing when the csupply cable enters the building there is the connetion fron N to PE.


Victron ESS setting wants to earth neutal in case of inverting, because it opend the relay that conncets incomming L and N.


I watched the video already before. In my case there are no loads installed yet. It's just a distributer with some MCBs RCD and bars for N and PE.


No connetion between N an PE bar. No loads either.

Do you think changeing thorder of the VE Bus cable would make a differnece ? Relay testing sounds like L3 L2 L1 one after another. L1 is the older one with GX module.


Tomorrow I will try again.


https://www.victronenergy.com/live/ve.bus:ve.bus_error_codes

Do you think that The L1 multi could be an issue here, regarding the serial number ?

SN HQ2041VEN8P

This war bought aprox 6 months befor the others.


Thanks for your thoughts


Ralf



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Alexandra avatar image Alexandra ♦ rl78 commented ·

In stand alone it must have connected fine then.

Usually doing a three phase we aim at same hardware revisions and serial set. Since that is recommended. So I have not had to deal with an older unit with two new ones.

Is your L1 the only one with a gx?

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Kevin Windrem avatar image
Kevin Windrem answered ·

Does the neutral star point on the output possibly have a path back to the input neutral?

You said that star point does not have a connection to PE but have you checked that with a meter? Maybe a connection in the load distribution panel you do not know about?

I wonder if only the ground relay in the L1 unit is active in a 3-phase system which is why you get the fault only when the L1 neutral is connected to the Multi.

I don't think the GX device would have anything to do with this fault or the ground relay test. But you could disconnect it and try powering the system without it.

What happens if you make one of the other units the master?

Just guesses.

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rl78 avatar image
rl78 answered ·

Hello Kevin,


I checked with a meter, but since the star point is connecterd in a neu distributer with no (not yet) loads and cabels installed there is no chance for a connection to a connection between N and PE.

It's just bars for PE an N with no connection to each other and some MCB and RCD for the loads. So far no loads are installed. I wantetd the system to be stable at first.


I think the problem my come that for example Multi L2 connects N to PE for thest, and Multi L1 tests for N to PE open...

Therefore i think its a timing problem.


GX disconnecting is ab bit tricky, I have to open the Multi L1 to do so.

I dont think that ESS can be operated without a GX ( the Grid meter is pluged here) but maybe an charger...


Same problem I see here is making an other multi the master. Isn't the master automatically the one with the GX ?


I do not have a Problem when I have Isolated the Neutrals from each other.


Therefore I an thinking timing overlap or something like this.


Thanks for you thoughts


Ralf





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rl78 avatar image
rl78 answered ·

Hi there,


I did some trying and meassuring...


Via VE Configure I can't disable the ground relay.


Via Victron connect and MK3 connection I can, and I did.


I did some testig, it appears that if you disable the groundig Relay via Victron connect, that only the testing is disabeld.


I disconnected the AC in Phase and the AC in and AC out neutrals and could still meassure the connection from PE to N. AC out phase was disconhected via mcb.

Then I removed the PE from the in and out terminals and the connection was still there.


Same behavior at all three units.


Has anyone similar experience ?



Have a nice day,


Ralf





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