Float switch with a 300ft wire

[RANDY SCHMIDT]

I have a 140' well pumping to a storage tank. The float switch is connected to a relay to engage the well pump. Right now they are within 10' of each other. I want to move the tank 300' away, up the hill so I can have some gravity feet to the house in the event of a power failure. Can the float switch & relay operate OK with 300' of wire between the two? I plan to use either 14ga or 12ga underground UF rated wire.

 

[Reach4]

120 volt or 240 volt relay? Should not be a problem.

 

[Sponsor]

 

[Valveman]

I have had problems with impedance between long strands of wire keeping the pump from shutting off. Switched to DC voltage to solve the problem.

 

[Reach4]

I have had problems with impedance between long strands of wire keeping the pump from shutting off. Switched to DC voltage to solve the problem.

Wasn't your problem run a lot longer than 300 ft?

 

[Valveman]

About 400' if I remember correctly.

 

[Reach4]

About 400' if I remember correctly.

Pretty close to 300. OK.

Was this a very sensitive relay maybe?

 

[Valveman]

Standard relay and control wiring.

 

[RANDY SCHMIDT]

Looks like its doable but I might need to switch to a DC relay if the pump doesn't turn off. I was actually more concerned that the resistance would not engage the relay. After looking at the wire chart looks like a 600' length of 14ga is about 2 ohms which should be OK.








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[Reach4]

If you can twist the current-carrying power wires to the pump, they will couple less power to nearby wires.

Separation of relay wires from power wires helps too, of course.

 

[Fitter30]

Heres a wire calculator. 120 vac x 1 amp x 300' you could use 16 guage
12vdc. X 200ma. X 300'. 14 gauge
https://www.inchcalculator.com/voltage-drop-calculator/