On a three-phase, 4-wire, delta-connected service where the midpoint of one phase winding is grounded, the service conductor having the higher phase voltage-to-ground shall be durably and permanently marked by an outer finish that is _____ in color, or by other effective means, at each termination or junction point.
a) orange
b) red
c) blue
d) any of the above
See answer and applicable Code reference
The correct answer is: a) orange
Article 230 outlines the requirements for service conductors and equipment for control and protection of services. Part IV of this Article covers service-entrance conductors. As per 230.56, "On a three-phase, delta-connected service where the midpoint of one phase winding is grounded, the service conductor having the higher phase voltage-to-ground shall be durably and permanently marked by an outer finish that is orange in color, or by other effective means, at each termination or junction point."