I recently purchased a used SA-6E compressor from a dive shop I work with. I had to switch out the NEMA 6-30 plug to a NEMA 14-30. This was done with a complete new plug and cable.

enter image description here

I connected the NEMA 14-30 plug exactly as the old plug was wired. However upon starting the compressor the compressor now stutters. I think it is not drawing enough power, did I wire the plug wrong? I have it plugged into a dryer outlet with a 30 amp fuse.

How many volts/amps does the Nema 14-30 normally put out through the black/red terminals? Does the red terminal/wire put more out?

1 Answer 1


NEMA 14-30 is 120/240V, with neutral to provide 120V from either hot to neutral. Hots are normally black and red and neutral is white.

NEMA 6-30 is 240V only with no neutral. Presumably in the old cord, black and white were the hots.

You need to cap off the new white wire (neutral) and connect the red (hot2) in its place to L2.

  • Thank you for the help I did as instructed and now I am up and running! Oct 29, 2014 at 4:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.