4 wire cable usage

[Calvin D. Cowles]

There were 2 4 wire (red, black, white & ground) cables (12AWG) with both reds and blacks connected to breakers (4 110v circuits). So single neutral and ground for 2 branch circuits, twice. I feel I should know if this is OK but....I ain't sure.
Shared neutrals/grounds? Don't remember the rules! Help appreciated.
BTW, branches were ceiling fixtures.

[Robert Meier]

What you've described is a MWBC or multiwire branch circuit which is fine as long as the two circuits sharing a neutral are not on the same phase.

[Calvin D. Cowles]

Thanks Robert,
My memory came back after I posted this!

[John Allingham]

Originally Posted by Robert Meier

What you've described is a MWBC or multiwire branch circuit which is fine as long as the two circuits sharing a neutral are not on the same phase.

You mean same bus, right. Single phase system.

[Robert Meier]

Originally Posted by jallingham

You mean same bus, right. Single phase system.

Yes, not connected to the same phase within a panel but this usage (a MWBC) is not limited to a single phase system. There is some debate as to whether or not in a 120/240 volt system we can call them phases since they're both physically on the same single coil of a transformer. We generally use the word phase even if by some definitions it's not entirely correct.

[Joe Funderburk, CMI]

A common example is the dishwasher and disposal on a multi-wire circuit. Always make sure a handle-tie exists on the breaker.