I'm getting a wet/dry filter with a new 240 tank. But the ? Is the room where the fish tank is going to be, sometimes the power goes out. And I was trying to find out if the water keep flowing or if it will stop?
Normally the water drains into the sump until it reaches the top of the overflow box or the mouth of the return line (always remember your return line will siphon water out of the tank).
When the power comes back on the pump will start pumping water back into the tank until it starts overflowing into the overflow box again.
Well firstly I would get an electrician to look at your power circuit...sounds to me like you have overloaded the circuit...
Adding a wet/dry along with a new 240 tank will only overload that circuit more so I would be getting that checked out asap.
When the power does go out...the pump in the wet/dry will stop working (obviously).
Water will then continue to flow into your sump. How much water continues to flow into your sump will be determined on how you have set up your overflows or how big your sump is...