[Jim Dawson]

A little late to the discussion, but I have been running the DC return to earth ground for years, works for me. One instance of where you would not want to do this is in the case of direct rectified line power without an isolation transformer, Anilam built a lot of systems like this. Grounding that would cause a dead short. As Gerry noted there are some other exceptions, but normally it is a good practice IMHO

[QuinnSjoblom]

A little late to the discussion, but I have been running the DC return to earth ground for years, works for me. One instance of where you would not want to do this is in the case of direct rectified line power without an isolation transformer, Anilam built a lot of systems like this. Grounding that would cause a dead short. As Gerry noted there are some other exceptions, but normally it is a good practice IMHO

Ok, I know you've set up a lot of control cabinets so I'll just continue to do it this way. It's how I'm set up currently and my machine has been 100% reliable.