Overflow non flood device

[robert]

Originally Posted by medican

hello......

Thats a great idea, so good that I was going to do the same thing to my tank. Then I got to thinking......... .......... I will be using a CPR 102 overflow and it is made to restart by using a powerhead to suck the air out of the top to start the siphon again. Now if the power goes out it will drain the back of the overflow trip the float switch and shut down the pump, now when the power goes back on and the pump does not start the over flow will not fill and it will not start to flow till you fix it.......

OK, here is my setup description. I have float switch in my main tank to protect against plugged overflow. When overflow stops the level of water rises, pushes the float switch up and float switch turns off the pump to avoid main tank spill over. Now, my tank is pre-drilled, but same idea would work on your overflow box. Switch is in the tank thou, not in the back of the overflow box.

Now, properly designed overflow box doesn’t loose the siphon when water level goes down, or power goes off for that matter. I know that CPR do, which is not proper design IMO. Let’s say that your overflow box “dries” and water in tank goes down when power goes off. Float switch, attached to your return pump, is in on position. Power comes back and your return pump together with siphon start pump goes on. If siphon start is behind the return pump, float switch would rise again and turn off the return pump until the proper siphon level is established to take the float switch to on position again.

Note: You might have problem if you use the same pump as return pump and siphon start pump, which is IMO and IME bad idea, regardless the install of float switch.