I am about to install a 3-wire well pump system, which involves a pressure switch and a control box. My question has to do with the wire I need to run from panel to control box, pressure switch, and pump. I know that I need to use 8/3 from the pump to the pressure switch/control box, but don’t know whether the panel to the pressure switch/control box can be 8/2 or also needs to be 8/3. I also am unclear on what is wired first from the panel, the control box or the pressure switch. Any sites that might have schematics would be appreciated, I haven’t found one. Thank you.
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Your question is confusing,,,,
It sounds like you have a three phase motor.
Anyway, google Franklin Electric,,,, you should find some diagrams there.
H
It is not a 3 ph pump, it's a 3-wire system that utilizes a control box to house the capacitors and relay, rather than having them in the submersible pump itself. The Franklin suggestion was good, they do have diagrams of their control boxes, and it does appear that the incoming wire need only be 8/2. The additional wire that goes from the pump to control box is a control wire of sorts. I still would like to find a diagram that included the control box, pressure switch, and pump to I can plan the layout.
Have you looked inside the control box? Often the wiring diagram is in there. That's big wire for a well pump.
You might try the control box manufacturer website.
You're running up against a couple conventions in the fine art of control wiring.
Control drwaings typically show the control wiring alone, only indicating the relay where the control circuit closed the pump circuit, to make the pump run. The pump wires themselves are not shown.
Let me make a few guesses, and see if it helps you any.
First, I assume by 'well' that you are taking water out of the ground and sending it somewhere. I also am assuming that there is some other place - perhaps a pressure tank or cistern - where it is determined whether or not you need more water, and tells the pump to operate.
In between those two places - at least in terms of the wires - is the control box.
So your control box should have THREE sets of wires entering it. The first brings in the power that makes it all work. This will be a circuit big enough to power the pump. This will have a 'hot' wire, a neutral, and a ground.
The second set goes from the control box to your actual controller - be it a float, pressure switch, whatever. Unless the pump itself draws less than 20 amps, this is not usually a 'full voltage, full current' circuit. Instead, it's supplied by a transformer in the control box, and needs just enough power to be able to tell if a switch is closed, then operate a relay (or starter). If it's low voltage, this cable might be little more than a 2-wire phone cable. (Three wires: pump on, pump off, and common).
The last set of wires is full size, and will supply power to the pump iteslf. They will not be shown on the wiring diagram, but the diagram will indicate the relay / starter where the attach.
NOW: As for the relay or starter ... there are two separate elements to it. There is a coil that creates a magnetic field, that in turn closed the contacts. The control circuit only powers the coil. The pump wires, as well as the actual power supply wires, attach to different screws, that go through the contacts.
If you haven't found the wiring diagram yet, I'll tell you how these are usually wired.
You don't say what kind of pump you have but I'm assuming it is a typical 240 volt submersible pump with a control box in the house.
If that's the case, you would have a 240 volt double circuit breaker in the box to feed all of this and then you may be required to install a manual disconnect switch near the control box.
So you would go from panel to (disconnect if required) and then to the pressure switch and then to the control box. All of this so far would be 2 hots and a ground wire.
You run that into the control box and run the 4 colored well pump wires out of the control box to the pump. The 4 that go to the pump are usually red, black, yellow, and a green grounding wire. You should see that diagram in the control box. Just hook the colors to the right terminals and you're good to go.