HELP!!! with DYI overflow

[vmprlrd]

I would like to build my own DYI over flow and i have done a lot of reading online but i an confused by few things.
1) what is the point of soo many loops in all the pvc over flows?
2) i live in an area where if it storms a lot, i could easily loose power. If i am not home is there any way where i can rig it so that the water inot the sump will shut off automatically once it reaches certain level so that the sump doesn't flood my room?
3) how do i know how strong of a pump to buy to pump the water back into the tank? thanks for answering these questions.

 

[Sploke]

1) if its the type I'm thinking of, the U loops are to make sure the siphon loop does not lose suction so if the pump goes off, the overflows starts working again as soon as the pump comes back on.

2) If your overflow is set properly, it won;t let very much water flow back into the sump, so you just need to make sure you keep enough space in your sump to handle this backflow.

3) If your overflow is rated for 600gph, make sure you get a pump that isn't rated for any more than that after head losses.

 

[owl]

1-to keep water suction always on , if it dosn t have these so many loops , when the water comes under the level u have to make the suction again and again !
2-that s why it has so many loops ! so when the power goes off and the return pump dosn t work the over flow will stop suction when the water reaches the edge of the inner pipe , so u ll not gonna have a flood , the water in the tank will stay in the tank and the water in the sump will stay in the sump , as soon as power backs on and water backs in tank the suction will start again automaticly ( cuz of those so many loops )
3-the overflow rates depends on pipe diameter , buy a pump that has abit less gph than ur overflow
if the overflows gph be more than ur pump it dosn t goin to be a problem but if the pump gph is greater than the over flow it will be BIG problems ! :
1-all the water in the sump/canister will go to the tank and it may become a flood ...
2-when all waters go in the tank there ll be no more water in the sump and the pump will work dry and u know the results ...

anyway ,u ll adjust the levels easily if u do well
just keep in mind to completely make the over flow airproof otherwise u ll loose the suction after while ,
adjust the overflow edge exactly where the edge of the water in ur tank is (maybe bout 1 or 2mm lower but i don think more !), and adjust the water level in the sump/canister 2" to 3" from the edge , to make some room from the remainin water that come from overflow if the powers goes off
good luck