I have ten different units each unit have the own panel and they are feed from the main disconnect with a 50 amp breaker each unit,and each panel have only one bar and I would like to know if I can put the neutral and the ground on the same bar? Each unit have the own meter I don't know if that makes any difference.

Is the feeder cable from meter to panel 3 wire or 4 wire?

Is 4 wires

You do know that neutral and ground are not the same thing, right?

Yes I know! But,I like to know if I can put the neutral and the ground in this case because the panels in each unit have only one bar, or should I just wire the grounds together with the ground coming from the main disconnect? Is 4 wires coming from the meter to the main disconnect. THANK YOU

The neutral bar needs to be insulated from any equipment grounds, and an equipment ground bar bolted to the panel metal box with machine screws is need for all grounds.

Thank you. So in this case the panels in each unit are sub panels? I just want to understand why is that in the main panel you can put the neutral and grounds to gether and the subpanel not?

If you accidentally end up with an open neutral the ground will act as a neutral and allow power to back feed to appliances and fixtures that are grounded. This could make it possible to get shocked by touching the metal cabinet of, say a washer, dryer, stove.

My instinct is when someone asks why or what will happen if grounds are connected to a neutral when not allowed, no matter what the explanation is, it will get done that way.

In addition to Ballengers advice, there are several techincal and safety reasons that the neutral and ground shall only be connected at the Main Breaker.

Short answer is, per the National Electric Code, the neutral and ground shall only be connected at the Main Breaker, and not allowed anywhere downstream of that point.

And that would make any difference if it was 3 wires? In the gronud and neutral been in the same bar? Jus want to know why is that in the main panel is allow to bee in the same bar?I always knew that you not allow to put the neutral and grouds in the same bar in the subpanel but, I din't know why.Thank you guys for you help I appreciate