When using an NEMA 18-60R receptacle, 3-phase, 4-wire, 120/208V, there is 3 hots and a neutral, where is the ground and how would the equipment that is plugged into this receptacle be grounded?
It can't. This config is a non-grounding one. It's a 4-pole, 4-wire config; you need a 4-pole, 5-wire config, which I haven't located yet, but they do make them. There will be either a pin or sleeve-contact for grounding.
John snuck in ahead of me. The number he supplied is a twist-lock plug.
Larry,
On my NEMA charts there is no configuration for a straight blade 21-60. You're probably right about its existance but it would be a non-standard configuration.
Hubbell makes a 4 pole, 5 wire Grounding "Hubbellock" Device
Cat # HBL 26520. The outer "shell" is the ground.
Its UL & CSA, but I don't believe it has a NEMA config. attached