4 wire to 3 wire 250V Outlet? Possible?


Old 01-26-18, 12:01 PM
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4 wire to 3 wire 250V Outlet? Possible?

Please Help! I am trying to change out my 250V outlets to accommodate another 250V outlet that would fit the plugs on the 2 laguna band saws I purchased. When I unscrewed the plate there are 4 wires (see pics), but on the new outlet there is only room for 3 wires. Is it still possible to change these out easily? I have attached pics for clarification. Thanks so much for your help!
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Old 01-26-18, 12:08 PM
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You have what is probably a 208V three phase outlet, and I assume your new saws are 240V single phase. First step is to check with the manufacturer or look at the nameplate stamped on the saw motor to determine if this saw can run on 208V.

Do you have an AC voltage meter to verify the voltage of the existing circuit? If so, turn the circuit on and carefully measure from each of the colors to green, and from each of the colors to each other.
Old 01-26-18, 01:51 PM
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Hi Ben- thank you for your response. I do have a meter and just measured the following-
Green-Black 123
Green-Red 123
Green-Blue 0
Black-Red 214
Black-Blue 0
Blue-Red 0

So does this mean it is 220?
Old 01-26-18, 03:13 PM
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So does this mean it is 220?
Voltage is nominal and listed by the NEC as 120,208,240,277, and 480v. 214 is closer to 208 volts not 240.

Based on your meter readings you only have two hot wires. The receptacle was surly a 3 phase receptacle, but it is possible that they have a phase converter if there is no 3 phase available in the building.

Most equipment will run OK on 208v but you should check with the manufacture first.
Old 01-26-18, 05:50 PM
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I would like to see the front of that first receptacle, it appears from the back to be a 3 phase receptacle like Ibpooks mentioned. Your new receptacles is definitely a 250 volt single phase receptacle.
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