Grounded Service Conductor / Grounding Electrode Conductor

M

Moistness

Member
Location
PA
Occupation
Senior Design Engineer
Hi all.
I have a question and will get straight to it.
When researching what size the Neutral should be on a simple 200A, 3-wire, 240/120V service, I found myself going around in circles.
A lot of people point to Table 250.66 Grounding Electrode Conductor for Alternating-Current System, but when I look into this, it seems this is a dirrenert conductor altogether. This conductor is only for the ground installed on a bus bar that the Service Neutral is also installed on, and ties to a ground rod, water pipe, or steel structure.

Other people point to table 250.102(C)(1) Grounded Conductors... etc. However, I believe this is for a neutral conductor that is not part of an incoming service, that is why I believe they left out the word "Service" in the Grounded Conductors title.

My question is, can someone point me to a chart that clearly outlines what the Grounded Service Conductor size needs to be? Or that the GEC is the Grounded Service Conductor.

Thank you in advance.
 
It needs to be the larger of the calculated greatest possible neutral load or the required EGC.

The reason for the latter is for fault-clearing, just like the EGC.
 
CoolWill said:
230.42, 220.61, 215.2 are all relevant.
Click to expand...

230.42 is the path I was looking for as it links to 250.102(C)(1) Grounded Conductors.

230.42 is under Part IV, Service-Entrance Conductors, in which the neutral is part of the Service-Entrance Conductors.

230.42 (C) Grounded Conductors states that the grounded conductor shall not be smaller than the minimum size as required by 250.24(D).

250.24(D) Grounded Conductor Brought to Service Equipment shall be installed in accordance with 250.24(D) (1) through (4)

250.24(D)(1) Sizing for a Single Raceway or Cable states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

And finally, I have a chart listing what the Grounded Conductor needs to be.

I apologize for writing all this out, but it helps me. I appreciate the help for all or you that responded.
 
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