Hi all,
I have a 3 phase Multi RS Solar A443 system, was running stable on latest firmware 1.30.
The new install ran great for 2 weeks or so in ESS mode. Now it suddenly reports error 59 AC-IN relay test fault: Contact issue. This happens on 2 of the three units (connected to phase L1 and L3).
I can however operate the system in Passthrough mode (relay closed), end seamlessly change to Inverter only mode (relay open). So the relay itself seems to be working.
I have no clue what can be the culprit. The last thing I did was remove the VE Can cables to re-run them while the system running.
I tried:
- Restarts as advised
- Checked wiring extensively.
- Checked 0-PE (0,8V)
- Tried restarts with no loads on AC out.
- Tried restart with battery off (as suggested elsewhere).
- Changed setup temporary to standalone changed phase L3 and L2, and started only the working L2 RS6000 which still passed the relay test. The error subsequently stayed with both faulty inverters.
- Observation: The 25A 300 mA RCBO on ACin trips often when the system does the relay check on RS6000 on L1 and the RS6000 on L3. It is a Hager AFM425G.
- When ever I operate the system in passthrough the RCBO behaves normally.
What could this be? I think - and hope it is a firmware issue.
On the topic of wiring: The RS6000 units basically replaced Multiplus II 5000 units that ran in ESS mode for 2 years with no faults on the same wiring.
** UPDATE**
I temporarily replaced the AC-IN RCBO with an 16A MCB to see if the RCBO trip causes the relay test to fail. It turns out that inverters on phase L2 and L3 start and operate normally on their respective phases (when I put them in stand alone mode), and that Inverter on L1 still fails the relay test.
I am inclined to think that inverter L1 is faulty?