Three Phase ground leads, location, theory

I am presently wiring a three phase RPC and installing a three phase panel with breakers to feed my present and future needs. The RPC is a 240 single phase input with 240 three phase output.
The leads coming out of the RPC to the three phase panel are two blacks, red and green.
Do I land the green from the output of the RPC to the ground lug that is not insulated from the panel or do I land it on the neutral bar that is insulated from the panel ?
My confusion lies in that no matter how I land it, how does the ground system work , since the panel isn't grounded to earth or the single phase sub panel right beside it ??? I keep thinking that I should be grounding the panel somehow ?
Thank you in advance, Mark

The green wire should be your "equipment grounding conductor".

it gets "grounded" to all the accessible metal in the system...... Boxes, conduit, machines, etc, and goes back to the ground rod (or water pipe connection). So it goes to the 'connected to-the-box" bar.

The isolated "ground bar" is really the neutral bar. Sounds like you do not have a neutral anywhere. You don't need one. So don't connect anything to it.

The two blacks should be the incoming 220V (both hot) and the red should be the "manufactured" phase.

If you do NOT have a green wire and/or continuous metallic conduit or EMT back to the service box, you need to install a green wire, picking up all the enclosures, machines, etc.

JST said:

The green wire should be your "equipment grounding conductor".

it gets "grounded" to all the accessible metal in the system...... Boxes, conduit, machines, etc, and goes back to the ground rod (or water pipe connection). So it goes to the 'connected to-the-box" bar.

The isolated "ground bar" is really the neutral bar. Sounds like you do not have a neutral anywhere. You don't need one. So don't connect anything to it.

The two blacks should be the incoming 220V (both hot) and the red should be the "manufactured" phase.

If you do NOT have a green wire and/or continuous metallic conduit or EMT back to the service box, you need to install a green wire, picking up all the enclosures, machines, etc.

Click to expand...

Thank you for the quick reply. I'm running EMT to all machines and they all have 4 wires, so I will run the greens all back to the panel for the 3 phase and land them to the ground bar.
I have a single phase 100 amp sub panel right beside this three phase panel. It has a separate ground on the panel enclosure,coming from the main, the neutrals are separate. I'm wondering if I can run a #8 wire from one panel to the other to accomplish the grounding ?? The main panel is a 200 amp service, ground rod and eufer ? grounding also through the rebar in the footings.

The 100 amp single phase sub-panel should have a grounding conductor run to it, from
the main panel, sized for the breaker that is feeding that panel.

The green grounding wire from your sub-panel, to the converter, should be sized
according to the conductors that are feeding the converter, that is the same thing
as saying they should be sized for the breaker in the sub-panel that is feeding
the converter. I don't know what size breaker that is.

Then each load machine should have grounding conductors run to them from the
converter, sized for the largest overcurrent protection that is in the converter or
up stream from it.

The design point here is, you want to the green grounding wire at any point along
the path to the load machines, to be large enough to trip the upstream protection
if there should happen to be a fault downstream.

Many folks will say that the EMT is enough for the grounding conductor by itself
and some codes allow this. I like to put the full-size green grounding wire into
the pipe as well though.

Belt & suspender kinda guy.

Jim