Hello,

I am wiring a vacuum pump for a vacuum-form table to a 220v. 3 wires coming of the wall - black and red (I assumed are hot) and white (neutral). I also have a vacuum switch (installed between the pump and the tank) and a main switch (to turn the table on and off).

The pump wiring diagram has a L1 and L2 posts. I guessed that will take the 2 hot wires. So where should I connect the neutral wire.

Since I plan to wire the whole set up in a loop, I assumed the vacuum switch and the main switch will only take one of the hot wires. Is that correct?

Let me know if my description doesn't make sense.

Please help.

Thanks

Usually if a 3 conductor with ground cable is used, it is for an appliance with both 200 and 110 components. The red and black are connected as L1 and L2 to the 220 v components. Either or both may be broken by a switch to control the circuit. A 2 pole switch provides a complete disconnect in the off position. Either the red wire or the black is connected to the hot side of any 110 component, and the white to the other side. Usually there is a bare ground wire connected to any metal housing of switch frame. If nothing except the 220 V vacuum pump requires electricity, I don't think you use the white wire. If a switch only has 2 contacts, just run the red or black wire through it. Post back if I haven't answered your question.

So let me know I understand your explanation.

See diagram on the pump.

Black wire goes to L1. Red wire goes to vacumm switch to main switch to L2. White wire goes to neutral/ungrounded post on the pump.

OR

Black goes to L1, red goes to L2 and white goes to vacuum switch to main switch to neutral/ungorunded post on the pump.

Thanks

The diagram was hard for me to read. I think it was instructions for running the motor on 110 or 220. Connect the wires in the motor as listed under high and then the black wire goes to L1. Red wire goes to vacuum switch to main switch to L2. Leave the white wire unconnected at the pump motor. Just use it if something else needs 110.

Hello,

Here I post the diagram again.

I thought the red and black are hot wires and the white is neutral. So to complete the circuit we have to some how connect the white wire.

Your latest picture is even smaller. Unless you have both 110 and 220 components, you only need 2 wires plus a ground. Many 220 appliances such as hot water heaters and air conditioners only have 2 wires plus the ground. Motors that can run on either voltage, still only use 2 wires on either voltage.

What do you meant by 2 wires? 2 hot wires (combine both the red and bLack) to one post L1 and the white wire to L2. L1 also said ungrounded wire.

OR

Connect black to L1 and red to L2 - don't use the white wire.

This pump can be wired to 110 or 220v.

Thanks

OR

Connect black to L1 and red to L2 - don't use the white wire.

This pump can be wired to 110 or 220v.

Yes. To wire the pump for 220, connect the various colored pump wires as listed in the high column in the diagram.

If you have doubts you can bring the pump to a pump shop and have them wire it up for you (if possible).