Jacko

On further investigation I discovered that there was another factor involved which was "skewing" the situation - my main grid incoming underground cable had a fault on the neutral (I suspect a break or poor connection). Once I replaced the neutral the situation has normalised, and I don't experience the same extreme voltage drops. The fault was difficult to determine and to locate

The system has been running reasonably smoothly for a while now on solar and battery. Recently, because of random, frequent power cuts I added over/under voltage protection on the Grid input. With the Grid input CB off, the Grid voltage is around 237v, but with the inverters operating in Battery mode, and outputting power from pv input, as soon as I switch on the Grid input CB, the Grid (connected) voltage drops to around 200v. Any idea why this should be, and what I need to change? My understanding is that until the inverter goes into Bypass mode, supplying the demand from the Grid, the Grid Input L&N wires are isolated from the Inverter Output, so should not be affected

Watchpower upgraded their servers at the end of May. They put out a warning that they would be off line during this process. I suspect that they made duplicate instances of each inverter/datalogger prior to doing this, in case something went wrong. To date these two instances still exist, and the records appear to alternate randomly between them - so when one views History the records are split between the two versions of the same datalogger. I just wonder if they ever intend to consolidate the instances, but suspect that their intention is to get their upgraded App "Energy-mate" working, and phase out Watchpower

I have not yet got round to doing the firmware upgrade - another thing to research first - but am monitoring the parallel inverters closely, and so far they are performing as (originally) expected. Hence I agree, the comms & current sharing cables were the root cause of the teething problems I experienced. I would imagine that firmware compatibility is dependent on the nature of the upgrade, and what aspect of the inverter is affected. So not knowing it is probably recommended to match the firmware, but in some cases it won't affect certain functions.

Thank you very much, I shall update the firmware. In the interim, I have linked both Comms sockets (2+2), and both current sharing ports (2+2) between the two inverters, and redone the parallel start-up procedure, and it appears to be working - under normal conditions (not high load, or bypass, or switching between modes)

Hi @Steve87 I have done all troubleshooting - plus more. Both inverters can adopt either the HS or SL status, but the fault condition occurs immediately when the status is "reversed". The Firmware is slightly different - Main CPU Firmware HS 69.06 and SL 69.05 Secondary CPU Firmware - both 12.21 The battery settings (05) are PYL and USE, and communication between the inverters appears to work iro battery levels, charge rate etc. I did not install the current sharing cable (as I erroneously believed this was associated with the DC output feature) but will put that in now, and report any change, forthwith - quite likely the cause. Thanks Silly question, but looking at the pic in the manual, they show both Comms ports, and both current sharing ports connected (2 cables each). Is this necessary - I saw somewhere that the comms connection is "either port to either port"?

I have two Kodak OG-7.2 inverters (each with their own, dissimilar, pv string), in 1-ph parallel configuration with a shared Pylontech battery bank. The inverter with the battery link Comms cable will not operate as the slave SL (very quickly goes to fault mode), but even when started as master HS, fails to fault mode every few hours. What I see is that the output load is generally not balanced, with the SL supplying most of the load. Every now and then, the Bus voltage on the HS, after operating at the same level as the SL, suddenly climbs (up to 30% higher), and the inverter switches to Fault mode - F60 Power feedback protection All cabling and connections have been checked, as have the settings. What might cause this unbalanced Output power allocation between the units, and what is the solution? Unfortunately, I only "monitor" with Watchpower, so not much data available. Any help would be appreciated