Help with wiring SMC valves

[Layed90]

As the title says I am replacing my fill valves, which make a terrible squeak noise when I air up, with new SMC fills.

The SMCs have two wires: 1 ground and 1 switch power I believe. My old valves have 3 wires connected to it that the previous owner installed. Anyone know what the third wire could be? Should I just splice it into the switch power when I connect them to my new valves? I'm stumped.

Thanks.

 

[Layed90]

Here are a couple pics showing the 3. The dump valves have only 2 wires so I don't know what this third one is about. You can see the grounded wire on the bag plate.

You must be registered for see images attach

You must be registered for see images attach

 

[Sierra]

With the smc valves, you have a 12v positive for activation and a ground. The other valve looks to have a positive, neutral, and earth ground. Just ground the black wire and then wire the red wire to your switch box that sends 12v to the valve when activated.

 

[Layed90]

So just hook up one of the black wires to the SMC red wire and hit the fill switch. 50/50 shot I guess haha. Thanks for the info.

What should I do with the earth ground? What exactly does that do differently than the standard ground wire?

 

[skylark]

So just hook up one of the black wires to the SMC red wire and hit the fill switch. 50/50 shot I guess haha. Thanks for the info.

What should I do with the earth ground? What exactly does that do differently than the standard ground wire?

It puts you on the ground! Just kidding, I don't have a clue.

 

[Layed90]

Lol umm thanks. Anyone with an actual clue? Could I splice the neutral wire with the ground/12V, or just ignore it? Not sure both are necessary.

 

[Sierra]

You tie the neutral and the earth ground together. Do not tie the neutral to the 12v positve.

The 3 wire valves are probably supposed to be used in industrial setting.

The neutral wire is for ground fault tolerance. In the event that a short happens, you will not get shocked when touching the valve or appliance. It is not meant to take take the full grounding load that the earth ground does. It can as long as you do not exceed the amp rating on that circuit.

Electric stoves, clothes washers and many other appliances with metal cases use this so that in the event that there is a short in the electrical you will not get shocked and it will blow the breaker.

 

[Layed90]

Thanks man appreciated