Page 80 of 456 Installing AC power
Figure 26
Multiple column – ground and logic return distribution
Large System
Cord or conduit
AC input
Service
panel 
120 V receptacle
IG or ACEG 
Safety ground (#6 AWG, min)
Logic return
LRE
reference (#6 AWG)
208/240 V receptacles 
(30 A L6 - 30
or
IG - L6 - 30)
AC conduit
AC conduit
