I am wiring a plug for a Miller 212 230 volt welder. 8 ga. Wire with a 50 amp double pole breaker. My meter shows 120 volts on each hot terminal and the ground is good. Nothing happens when I plug the welder in. I hooked my 230 volt compressor to this receptacle and show 120 volts at each point in the compressor switch, but again, nothing happens. Thoughts.

Can you read 240 volts across both hot legs?