NEC 690.16 - How can I combine three 450V strings with overcurrent & disconnect?

[laszlo]

Vic,

I have spent a great deal of time researching offgrid A/C solutions -- this was at the time when PV was still very expensive >$5 watt.  What I ended up using in the house is the Mitsubishi Mr. Slim, ductless, 26 SEER, mini-split air conditioner, and it has worked out great for me. 

Looking at your system from your profile, you have plenty of power to run an A/C but even with that sort of power available  I recommend the Mr Slim since it's a high quality heat pump system system that will make you comfortable year round.

What I am getting now for the house is a heat-pump based water heater -- this also cools and dehumidifies the house so you get a water heater as well as air conditioner in one. I have a solar (thermal)  water heater as well, but this heat pump water heater is actually making sense now with the PV prices so low.

Hi Robin,

Thanks for the guidance.   Keeping the electronics and batteries COOL is a good thing.  Have A/C in the power room,  here,  and it takes priority over the A/C in the dwelling.  Altho,  for the new system/location,  still do not quite have the new arrays on the roof,  so not enuf power to run A/C,  yet.

Vic

[Vic]

Hi laszlo

Thanks for the info.  YES,  mini-split A/C is on my shopping list.  Because my spaces are small,  have been looking at the mid-sized Sanyo split Heat Pump (multi-zone),  but the favored supplier has been out-of-stock for months.  These units are only about 17 SEER,  but think that goes with the small units.

Our climate in Northern Calif is fairly moderate,  and this year has been more moderate than normal,  which means that will probably have big-time heat for the next few years.  The new cabin project has only about 500 Ft Sq,  on two floors,  plus about 160 Ft Sq for the power room,  so three zones should do it.  Thanks for the info,  Oh,  BTW,  my existing system has panels that were about $4.75/ watt,  delivered (altho they are very rugged Shell SQ series,  and have REAL junction boxes!).

OK.  Thanks again,  Vic