some sort of inverted float switch?

[beanybot]

Hi, my first post here so saying hello aswell

I was really hoping someone could help me with a bit of trouble im having. (probably fairly easy for you guys).

Im looking for an inverted float switch. I guess thats what it might be called, Im not sure.

Basically what I want is a float switch connected to a pump that will come on to keep something full, rather than keep it drained (as you would typically find on a float switch in a boat for example).

The pump is pumping a liguid (vegetable oil) into a filter sock (7inch by 15inch) which in turn hangs down the top into an oil drum. The problem is it takes quite a while to filter through the sock (much slower rate than the pump pumps at) so basically I dont want to have to stay there all day turning the pump on and off. It would be ideal if i could get a float switch that would come on the fill the filter and then as the level rises to the top it cuts off. then halfway down comes on again. and so on and so on.

I hope you guys will know of something.

Thanks alot !

 

[Biggles..]

Standard wieghted float swithes can do either just depen on if they're wired no or nc(normally open/closed)
size and length of float are probably the problems as they're normally used in large tanks.

 

[Onetap]

Bio-diesel I presume.

You really need two float switches, the lower one starts the pump and latches a relay in, the upper one breaks the circuit and stops the pump. I'd suggest pumping the oil into a tank, say a 4-gallon F&E tank to give the pump a reasonable run time. Rapid start/stops will burn the motor out. The outlet from the tank could have a valve on it to restrict the flow to a trickle into the filter sock.

CPC and Radio Spares sell float switches. A high level alarm might be worthwhile, depending on how big a crisis a spillage would be.