multi wire branch circuit grounding

[mariocast]

im running 12 120v lighting circuits sharing 4 neutrals from a 208-120 panel. how many egc's do i need?

 

[George Stolz]

How many raceways and type of raceway?

 

[infinity]

For all in one raceway, one EGC.

 

[Smart $]

im running 12 120v lighting circuits sharing 4 neutrals from a 208-120 panel. how many egc's do i need?

How many raceways and type of raceway?

One per raceway or multi-conductor cable

 

[mariocast]

1 2" emt. room for additional circuits.

 

[roger]

1 2" emt. room for additional circuits.

You do realize that the 12 current carrying conductors you are already installing are only good for 50% of their 90 deg rating and if you add 8 more it will even be less don't you?

Meaning if you are using # 12 THWN conductors they are only good for 15 amps before you add any more.

Roger

 

[George Stolz]

But on the bright side, your original answer would be zero conductors - the EMT can be your EGC.