Gateway power cuts ?

hi guys,
I have the Ver 1 gateway and a 13kw AIO. when I turn the main switch i have in my meter box ( i.e simulating a power cut) its around 30 seconds before the AIO cuts in and runs the house ! is the normal ? or should the AIO pick up the house instantly ? GW on V10 Aio on V16 firmware.
I thought it should be more like a UPS i.e instantaneity , thought a comments welcome..

rob

rob c There is a setting that needs to be changed either by your installed or GE support called: "Enable 0 Second EPS Countdown" - I don't think it is set by default.

thanks CW ...