Quote Originally Posted by Neale View Post
Why leave the 24V supply floating wrt earth? Take the 0V connection to the control box star point and all will be well. Can't see any reason not to ground it. That's what would normally be done - my control box has a 24V smps and a 5V+12V smps and all the 0V connections go straight to the star earth.
Is that really recommended? Doesn't it defeat the purpose of the galvanic isolation?