I accidentally pulled 6-4 wiring to a machine that only needs 240 and no neutral. What to do with the white wire?

I read here that at the machine, I just cap the white wire. When I go to connect the wires in the main breaker panel, do I still connect the white wire to the neutral bus, or do I cap it in the panel as well?

  • best to connect at breaker panel ..... or cap at breaker panel also and label both ends with a reference to the other end being capped ... local electrical code is the final judge. – jsotola May 1 '18 at 22:20
  • Is the breaker for the circuit a two-pole common-trip breaker (the common case), or something else (such as two one-pole breakers linked by a handle tie)? – ThreePhaseEel May 1 '18 at 22:44
  • @ThreePhaseEel The typical 50 amp, two pole breaker – Josh May 2 '18 at 12:58

Cap it at both ends. If you're using a wire nut, also tape the nut on, they have trouble sticking to single wires.

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  • Out of curiosity, what makes this a better idea than, say, grounding it in the panel and capping it at equipment? Is there a security and/or code issue? – Jeffrey May 2 '18 at 13:36
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    It can't flow unexpected current if it's not tied to anything. It also can't violate code for wire colors. Imagine a white wire landed on a ground bus. Next guy needs a neutral, it rings out good, he uses it, gives it no further thought. It's on the ground bus. If you land it on a bus, land it correctly or not at all. – Harper - Reinstate Monica May 2 '18 at 13:50

Land it on the neutral bus

Since you have the correct breaker in there for a mixed 120/240VAC circuit, simply land the white wire on the panel neutral bus -- this way, it'll be readily available for someone in the future who wishes to repurpose this circuit.

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