Sizing Ground

[SiddMartin]

Two Questions maybe three

1. 300A Panel, taking all the homeruns to a trough in the attic. Put ground bars in the trough to eliminate taking all the grounds down to the panel. What size ground do I need to take from panel to the ground bar in the trough? Do I need to bond each g-bar in the trough? (I have 4)?

2. Each conduit that goes from the panel to the trough, does each conduit need a ground in it? I heard this from another foreman, but could not find anywhere in the code requiring each conduit to carry a ground.


- I would like to run 1 ground sized properly to the g-bar in trough and terminate all homerun grounds there.

 

[stickboy1375]

Use EMT and you wont need any grounds... :grin:

 

[SiddMartin]

Use EMT and you wont need any grounds... :grin:

the conduit from the panel to trough is EMT

 

[stickboy1375]

the conduit from the panel to trough is EMT

still want grounds? The size of the ground would be based on the largest branch circuit.

 

[SiddMartin]

thank ya sir

 

[Rich Elec.]

Take a look at 250.122 (C).
Rich

 

[Dennis Alwon]

the conduit from the panel to trough is EMT

The emt is code compliant as an EGC. You do not need any wires, however if you want to run one then you only need to pull an EGC as large as what would be necessary for your largest conductors based on 250.122. Thus if your largest wire is a #8 in a conduit and is connected to a 40 amp breaker than a #10 EGC is all that is necessary