I’m a helper and worked with an old time electrician and he did something a year ago that still troubles me. We wired a 50 amp 220 volt circuit for some heat pumps. he brought the wires into the panel, hooked them to ground and the breaker and left the white wire capped with a wire nut. He told me it will work fine and forget about it. Did we leave somebody with an open neutral? Is the ground wire the neutral now? Should I try and go back and fix this?
This is correct. Direct connection to a 220/240 appliance takes two hots – one each from opposite ends of the phase – and a ground. No neutral is required. (You may even find a sticker inside the wiring panel to the effect of, “Do not connect any neutral wire.” The mini split I just installed had one, for instance.)
Some people treat ground and neutral as interchangeable since in residential applications with only a single breaker panel they are often bonded at the panel anyhow. While you can get away with this in a variety of scenarios, doing so is not technically correct.