I just bought a new Delta Unisaw, but am having trouble wiring it. It is a 20 amp 230 volt saw. The existing wiring in the shop has 2 black wires coming off a double 30 amp breaker, at 120 v each. I attached 1 wire to one side of the socket, and the othjer wire to the other. When I measure the voltage across the tabs I get 240 volts, but my saw still won’t turn on. Can anyone help me?
Thanks
ORV
Replies
you have a good ground?
Not sure, i wired the ground of the switch to the box. Does it not work without a good ground?
What do you mean wired the ground to the box? BTW 220 has no neutral, so with no ground there is no circuit.
At the breaker there is only 2 wires, both black. In the box I have 3 blacks, a white and 2 green. I figured out that the two blacks carry 120 each from each side of the breaker. I left the white and extra black wires alone. The I wired a 120 black to each terminal of the outlet, then I twisted the two greens together, tied them to the ground screw of the outlet and screwed them (also) to the back of the metal box that houses the plug.
Is your saw a dual voltage saw which is wired internally for 120 volts?
John
Thanks everybody, I just got it figured out, embarrassing as it is. One side was prone to popping off the screw, but only after the outlet was installed. I screwed it down but good now, and it works great. What a fabulous saw!
Thanks again.
ORV
Excellent! Enjoy your saw :)
"BTW 220 has no neutral, so with no ground there is no circuit"
That's not true. The ground (green or bare wire) is there strictly for safety reasons. It is not normally part of the circuit. In a 220V circuit, current flow between the two hot conductors.
You're absolutely correct.
However, some 220 circuits (for a dyer, as an example) do contain a white wire. This is because some components (timer, light in the inside) run on 120 volts and use one of the hot wires plus the neutral for this purpose.
(I added this not for you but the other poster who claimed 220 had to have a neutral.)
John
Yup, and such circuits are termed "240/120V". But a unisaw ain't one of them.
And to confuse things further, such 240/120V appliances used to be able to tie the neutral to the appliance frame, and use it as a ground -- a practice of dubious safety, done just to save running another wire and using bigger connectors. Fortunately, the NEC was changed to disallow this.
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