Hi
i sometimes have problems with ground relay tests failing, when my system connects to the grid.
I think the problem is, that my electrical installation is quite large and old and the isolation resistence between neutral and earth is just above 1 mOhm. If i disconnect the elctrical installation from the Multis, the ground realy test does not fail.
What does the Multiplus measure during the ground relay test ? Resistance between neutral and earth? What is the lowes value that it will accept?
Hi @Nico Bayer,
Error 8 or error 11 (Ground relay test failure) occur when a MultiPlus-II series has failed one of its internal relay tests. These test are performed to make sure that the relays that connect and disconnect an MultiPlus from the AC input are operational.
When these relay tests fail it can have two reasons:
• The installation around the Multiplus has an issue and this causes a follow-on effect in that the MultiPlus-II fails the relay test.
• The MultiPlus-II has an internal fault and thus it has failed the relay test.
Error 8/11 is a 15 step internal testing procedure. Exactly which step fails can give some indication to the source of the issue and what can be done about it.
Relay error testing procedure:
• Eliminate external sources.
• Connect unit to DC.
• Connect unit to AC, but not yet turn AC on.
• Connect the unit to a Color Control GX.
• Turn unit on.
• Confirm that unit starts inverting.
• Turn AC on.
• Confirm that the unit starts charging.
• If during this test you get an error 8 or error 11 note down the error and the step number.
• Find the error and/or the step number in the table
• Report the error code and test results to your dealer.
Error Error Step
8 GND Relay Error Ground (RL1) fails to close or is shorted
8 PE2 open error Ground (RL1) fails to close
8 PE2 closed error Ground (RL1) has failed shorted
11 Error occurred, step 8 K1 has failed shorted
11 Error occurred, step 7 K1 and/or K3 fail to close
11 Error occurred, step 6 K3 has failed shorted or R12 is open.
11 Error occurred, step 5 K2 has failed shorted
11 Error occurred, step 4 K4 has failed shorted
11 Error occurred, step 3 K2 and/or K4 fail to close
11 Error occurred, step 2 K4 has failed shorted or R12 is open
11 AC0 /AC1 mismatch Calibration or hardware issue
11 Communication error Hardware issue
11 U Mains mismatch Calibration or hardware issue
11 Period Time mismatch Hardware issue
11 Drive of Back-feed relay mismatch Hardware issue
Hi
Thanks for your detailed reply. My system fails with step 8 "GND Relay Error Ground (RL1) fails to close or is shorted "
That confirms that there is a short circuit between neutral an earth somewhere in my electrical installation with a quite high resistance. I will keep on trying to find it.
@Nico Bayer There is a youtube video that explains the error and how to fault find:
https://www.youtube.com/watch?v=OU4x5CqiJdw
Hi Guy.
If there is an RCD (GFD, RCBO or whatever the terminology is in different countries) on the AC output of the Multiplus II 48/5000 then if there is an Earth fault shouldn't the RCD detect this and trip? I've seen it now on two Multiplus 48/5000 where it fails the earth relay test with "8 PE2 closed error Ground (RL1) has failed shorted". Checking the installation downstream of the AC Output there is no evidence of a fault and when the downstream system is powered from the grid then all works fine.
The RCD is a Type B 30mA sensitivity, does the Multiplus have a much more sensitive detection than the 30mA of the RCD?
The systems work fine and feed back to the grid in ESS mode but one of the systems fails every few days with the GND Relay error and the other system fails all the time meaning that the critical loads on AC Out 1 keep getting turned off due to the failed test.
Is the solution to replace the Multi's as there might be an internal error? Not sure what to do next.
my problems with the ground relay test were caused by a device with a ground fault. The ground fault was quite difficult to find. I hat to check every circuit in my house with a isolation resistance tester to find it.
If the error is still present when all cables are disconnected, the ground relay itself can be the problem and your device has to be repaired.
