Hi Folks,
I have an incredibly simple circuit that is regularly giving me problems.
I have a small irrigation system, at the base of this is a small sump which needs periodically emptying into the main water holding tanks.
To do this I have installed a small 12v pump, switched by a float switch. The circuit is extremely simple (see diagram attached) comprising a 12v supply, connected to a float switch (NO) then feed to 12v pump. When the tank fills the switch changes to NC and the pump activates, until the water level drops and the switch returns to the NO position.
I installed a Cynergy RSF40 https://uk.rs-online.com/web/p/float-switches/0339730/ float switch This worked initially, but then I found that it would not turn off once the initial contact was made. I tried replacing the unit with the same model, but found that after a short period of time the same thing would happen (in all cases the valve is free from obstructions within the sump).
Testing with a continuity tester, found that both appeared to be working fine.
I then tried an alternative, a top mounted float switch RFS50 https://uk.rs-online.com/web/p/float-switches/0845960/ and this seemed to work, but I have just found that the pump is still running even when the tank is dry (and the switch should be off).
I wish to retain the low voltage (12v) system as it is an area that is potentially exposed to the public and wildlife.
Testing the circuit without the float switch finds the system runs correctly.
Any thoughts on why I might be having this recurring problem? Is the switch arcing across somehow?
Thanks for any tips or advice
Mark
I have an incredibly simple circuit that is regularly giving me problems.
I have a small irrigation system, at the base of this is a small sump which needs periodically emptying into the main water holding tanks.
To do this I have installed a small 12v pump, switched by a float switch. The circuit is extremely simple (see diagram attached) comprising a 12v supply, connected to a float switch (NO) then feed to 12v pump. When the tank fills the switch changes to NC and the pump activates, until the water level drops and the switch returns to the NO position.
I installed a Cynergy RSF40 https://uk.rs-online.com/web/p/float-switches/0339730/ float switch This worked initially, but then I found that it would not turn off once the initial contact was made. I tried replacing the unit with the same model, but found that after a short period of time the same thing would happen (in all cases the valve is free from obstructions within the sump).
Testing with a continuity tester, found that both appeared to be working fine.
I then tried an alternative, a top mounted float switch RFS50 https://uk.rs-online.com/web/p/float-switches/0845960/ and this seemed to work, but I have just found that the pump is still running even when the tank is dry (and the switch should be off).
I wish to retain the low voltage (12v) system as it is an area that is potentially exposed to the public and wildlife.
Testing the circuit without the float switch finds the system runs correctly.
Any thoughts on why I might be having this recurring problem? Is the switch arcing across somehow?
Thanks for any tips or advice
Mark
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