How to wire a 8 pin relay, 2 float switches and a solenoid with 2 power supplies

Submitted by ionized_fallout t3_yf61qe in DIY

What I want to accomplish is one float switch at the bottom of a tank and one at the top.

When the bottom switch in the tank reaches the low point it opens a normally closed solenoid and causes water flow to fill the tank. Once the “full” switch at the top of the tank rises I need the solenoid to close.

Any help with this would be greatly appreciated.

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ionized_fallout OP t1_iu1vlu9 wrote

I should specify these are 2 wire float switches and not 3.

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KrazyKuch t1_iu210rv wrote

Google start stop schematic and it will basically show what you need to do... Note both the top and bottom float switched must be mounted so that they both read closed when the vessel has no water.

Wire the bottom float switch to a common and normally open contact on the relay. Then take hot wire and splice it to one wire of the top float. Then take the other wire from the top float and connect it to the common relay point that you used for the bottom switch. On the normally open contact that is used with the bottom float take a wire to the coil contact for the relay, and the other coil contact goes to your neutral from the power supply.

All thats left is to use the other normally open contact on the relay to turn your solinoid off and on

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Krypt0Deadbeef t1_iu2ndnf wrote

You mention two power supplies and an 8 pin relay. What is the part# of the relay, and what are the power supply voltages? I assume the solenoid valves are 120 volts AC.

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PerspectivePure2169 t1_iu2qdf2 wrote

Replying to KrazyKuch (#270,989)

This is the answer. I've done this exact job and the float switch manufacturer had wiring diagrams for all the various pump control options to show how to do it. OP can find one for his or use a generic one.

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Techtopics t1_iu2uqqo wrote

That’s a simple automation circuit with a relay. Part of my job is software development and automation processes. Let me know if you need help with a schematic

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Krypt0Deadbeef t1_iu326lm wrote

Replying to ionized_fallout (#276,321)

When the Low Float rises, CR1 turns on to indicate Not Low. On the 5V section, the circuit is activated if the NC contact of CR1 is true (Not-Not Low, which means Low) and the High Float is Not High (needs to be NC) then the solenoid is powered along with CR2. The Low is sealed in by the CR2 contact so that when the tank starts to fill and the Low Float causes CR1 to change state, the valve stays open. Once the High Float activates, it opens the circuit, closing the valve and removing the CR2 latch.

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