NEC 250.102(C)(1)

Status
Not open for further replies.

Zyb

Member
Location
Maine
Occupation
Design Engineer
For the ground wire on line side tap, do I need to use 250.122 or 250.102 table? Thanks

1673634975550.png
 

packersparky

Senior Member
Location
Wisconsin
Occupation
Inspector
250.102(C). Also #2 is not large enough. You need a 2/0 copper or 4/0 aluminum. The total kcmil of your conductors is 750 kcmil.
 
  • Like
Reactions: Zyb

Zyb

Member
Location
Maine
Occupation
Design Engineer
250.102(C). Also #2 is not large enough. You need a 2/0 copper or 4/0 aluminum. The total kcmil of your conductors is 750 kcmil.
Does it need to be one 2/0 copper ground or I can use (3)#2 cu? means one #2 each parallel. thank you
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Consulting Electrical Engineer - Photovoltaic Systems
Does it need to be one 2/0 copper ground or I can use (3)#2 cu? means one #2 each parallel. thank you
There needs to be a full sized (2/0 in this case) ground in every conduit of a parallel set.
 
  • Like
Reactions: Zyb

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
There needs to be a full sized (2/0 in this case) ground in every conduit of a parallel set.
This appears to be a supply side bonding jumper and, unlike an EGC, only needs to be sized for the ungrounded conductors that it is installed with.
In this case a 2AWG supply side bonding jumper in each raceway, on the line side of the 800 amp OCPD, assuming that is 3 raceway installation. It will need a 1/0 equipment grounding conductor in each raceway on the load side of the OCPD.

This exact layout really points out how flawed the code is in this area. The worst case, in my opinion, are the conductors on the line side of the OCPD, and we only need a 2 AWG in each raceway, but on the load side of the 800 amp OCPD, we need a 1/0 in each raceway.
 
Status
Not open for further replies.
Top