[RE-wrenches] Parts List For AC Couple Disconnect

[Mark Frye]

Folks,

Can anyone share a parts list for setting up a AC couple disconnect?

I want to couple a non-frequency response grid-tied inverter to a 
battery based stand-alone inverter.

I have only 8 amps output from the GT inverters, so can use 10A relay 
contacts.

I want a device to monitor AC voltage and latch a coil on when it raises 
above a set point (250VAC). I then want a timer to release the latch 
after about 1 hour.

Sound about right? Are any vendors selling such a device? How about a 
parts list from Digikey?

Thanks,

Mark Frye