I may have submitted this question before but not sure I did it correctly

A friend of mine has a jointer and a table saw... Duel voltage motors... I noticed that both were wired with only two wires... Someone converted them from to 110 volts to 220... First of all I'm sure this is not safe... My question is... Will this equip. run efficiently, and please explain how the circuit works without the third wire... thank you...

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Why are you sure this is not safe?
Both 120v or 240v only require two wires (plus a ground). A straight 240v circuit or load does NOT require a neutral.

If you had a Dryer or a Range, the newer ones use the 2 hots and a neutral plus the ground, because it has 120 and 240 volt devices, the ground is for safety, and keeps equipment at ground potential.

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Originally Posted by svoboda

I may have submitted this question before but not sure I did it correctly

A friend of mine has a jointer and a table saw.........Duel voltage motors...........I noticed that both were wired with only two wires..........Someone converted them from to 110 volts to 220............

[email protected]

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Dual voltage motors are converted from 110 to 220 by changing the taps in the motor connection box.
There should be a wiring diagram either on the motor nameplate, or on the inside of the connection box cover.

Basically, you connect the motor coils in series for the higher voltage, and parallel for the lower voltage. The motors will burn out if plugged into the wrong voltage.

As others have posted, you need a grounding wire with either voltage.

Forgot to answer your other question:

The motor needs only two wires to operate. The grounding wire is for safety purposes. It normally does not carry current.

The grounding wire is connected to the metal frame of the equipment. If a live wire comes in contact with the metal frame, the grounding wire intentionally creates a short circuit that trips the breaker or blows the fuse.