Hybrid solar system powering whole house but not central AC when grid is down

[sanf88john]

I am trying to design/build a hybrid system which will help to power whole house using PV when grid is up (including central AC to save electric bill). But when grid is down, I want the system to power everything except for central AC. Is there any hybrid inverter with multiple outputs? (critical load output and another output which is powered only when grid is up). If there are no such hybrid inverter then is it possible to use some kind of 230V "smart" relay breaker switch for central AC which is enabled only when it senses grid power is available?

 

[DThames]

SolArk SmartLoad might be an answer. It might need one of their inverters, I have not checked. I just saw something on it and have yet to dig into the details.

 

[SparkyJJO]

I am trying to design/build a hybrid system which will help to power whole house using PV when grid is up (including central AC to save electric bill). But when grid is down, I want the system to power everything except for central AC. Is there any hybrid inverter with multiple outputs? (critical load output and another output which is powered only when grid is up). If there are no such hybrid inverter then is it possible to use some kind of 230V "smart" relay breaker switch for central AC which is enabled only when it senses grid power is available?

My Outback unit has a programmable AUX output that could be used to drive a relay pack. Possible you could find a 230VAC relay that is controlled by something like that and have the inverter set to open or close the relay (depending on type) when grid is up vs down? I don't know exactly the level of programming I can do on mine, I haven't looked into it very much.

 

[sanf88john]

My Outback unit has a programmable AUX output that could be used to drive a relay pack. Possible you could find a 230VAC relay that is controlled by something like that and have the inverter set to open or close the relay (depending on type) when grid is up vs down? I don't know exactly the level of programming I can do on mine, I haven't looked into it very much.

Outbacks and Solark are top tier inverters and I wouldn't be surprised if these have such options. But for cheaper certified inverters (like EG4 6500ex), yes I found out that there are 230V AC contactor relays (40, 50, 60 amps) which are driven by 24 volts. They are typically used inside central AC systems, but I don't see why they can't be used independently installed inside an electrical box. . But for my purpose, all I need is 24AC power brick plugged into grid enabling the 240V contactor relay. When grid goes down, so does the contactor relays. But I am not sure if local building department will have any objections to such setup.