General Order 128
Section III
Requirements for Supply Systems
36.4 Ground or Earth as a Conductor
Ground or earth shall not be used as a normal return or circuit
conductor. In direct current supply systems or in single phase or polyphase
supply systems, a neutral or any other conductor shall be used under normal
use as a return or circuit conductor; however, the grounding of the neutral
or any other conductor is not permitted as a normal return or circuit conductor.
The neutral or any other conductor is permitted to be grounded only for the
purpose of stabilization and protection, and applying impressed current cathodic
protection on portions of circuits used for that purpose.