question

I think is should work to connect 2 phases the device (not 100% sure!), but you will have a delay of around 30sec-1min before AC IN 2 is passed trough.and vise versa.

But if this problems are only at L1 why you don't change the wiring that the Ouattro is always on L2 or L3?

Hi Matthias,

Thank you for your response. It’s a pity though, that it would take some time for the switchover to occur, but still definitely better than the current situation.

Regarding your question, no, all three phases go through these cycles of high and low voltages, but fortunately they‘re such that at least one of them would be in ‘normal’ range when my main supply is too high. This does mean that there would still be some times when my ’selected back-up phase‘, to be connected to AC-2-in, is also high when the other one is high, but in the long run it would still be an improvement relative to the current situation.

I think that even if you switched to a different phase ahead of the inverter, it would still drop out until it resynchronizes to the new phase.

You might look for an automatic voltage stabilizer to monitor and adjust your incoming power line. These are typically autotransformers or transformers that switch in/out to boos/buck the line voltage. Searching the web for "automatic mains voltage regulator" may turn up something useful.

Thank you Kevin. I have looked into AVRs about two years ago, when I first wanted to solve the voltage issue. At the time, the voltage fluctuations were even more crazy, ranging to about 305V. Most AVRs (or at least affordable ~15kVA ones), we’re only rated for up to about 260V and the one sales person told me it would switch out at higher voltages and other brands might just get damaged at the higher voltage end. So I ended up buying the Quattro and batteries to protect my equipment and also assist with load shedding here in South Africa, whilst I knew I’d add solar panels to the system in the not too distant future. Now I have done so, and want to maximize the use of those panels, while not wasting battery reserve on the non essential loads when municipal power is really not available. Hence my need to still make use of the AC-2-out functionality on the Quattro. I could otherwise just have put all the loads on AC-1-out, but it would risk depleting the batteries at times I’d like to conserve for essential use and would occasionally also result in overloading the Quattro (when council has high voltage and therefore power assist is not available).

Many thanks Cristian. This certainly looks like an option to seriously consider. I didn’t know that these selectors existed. I will definitely look into it. So far, whenever I have tested the voltage at my distribution board, there has always been at least one phase within the acceptable range. So, although it seems that the 0,5-0,8 seconds these things take to switch between phases, will cause my AC-2-out to drop out, it will at least be available again within about 2 minutes.

Thank you very much for the suggestion.