Ok, the SH10000 is a 45A unit, on a 15/45 meter this would be the smallest unit I would install to cover the whole house, the next size up (15000 / 68A?) would likely be the ideal unit with no danger of overloading it with your beastly A/C.

excellent crossy thank you...and everyone else who posted on this thread...I'm sure you all know how helpful you are but I'm gonna say it anyway...you guys are really helpful...I woulda been lost without this forum...thanks again...

oh, and crossy...I shut the AC off and turned it back on...3 min warm up and it only dropped to 185v for a split second and jumped back up to 220 instantly...I think we've done it! Now I can look forward to thousands of baht extra on my leccy bill...

thanks again...I'll report back once it's all wired up correctly...hopefully with good news... and we can close this thread...

success!!

The monkeys from the installation company never showed up...no money in it = typical Thai business practice...

So I wired it up mysef and crossyed my fingers and viola...it works like a charm...

it's now wired through a 32amp wall mounted breaker and on it's own circuit with a new 32amp consumer box breaker using 4sqmm wire...

there is an instantaneous drop to 185-ish volts when the compressor kicks in and right back up to 220v...

I haven't got the AVR yet, but I will...but for now it's working and I can live with it...

to all who contributed to this thread, I thank you. You're advice is invaluable and special mention goes out to Crossy...

Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You Thank You

PermaNewb

Great.

To be honest, unless you have other unwanted effects, I'd save the money for the AVR at least for now. Prolonged low voltage does induction motors no good whatever, but a short dip on starting shouldn't cause serious issues.

Here in Phuket, 2 of my small hotels are right 'at the end of the line' as far as the 3-phase supply is concerned. We can start our air-cons OK with a voltage drop down to about 180 volts and then recovers back up to something between 190 - 220 volts.

We use low BTU air-cons to avoid overloading the electricity supply. Our local PEA warned us that 'supply collapse' will definitely win us no friends at the PEA office......

So I limit the number of air-cons and instant water heaters on each phase. Luckily, many guests don't like air-con and prefer fan rooms