Question

On a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, only the conductor or busbar 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.

a. blue
b. green
c. orange
d. yellow

Answer 1

In a delta-connected system with a grounded midpoint, the conductor or busbar with the higher phase voltage to ground should be marked with an orange color for correct and safe identification.

Step-by-step explanation:

In a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, the conductor or busbar with the higher phase voltage to ground must be marked conspicuously. The correct identification color for this purpose is orange. This color-coding helps ensure the safety and proper identification of electrical components. It’s important to note that wire insulation colors can vary by region, so always verify local standards. The earth/ground wire, which is often green, yellow, or a bare wire, may sometimes have a striped coating to aid those who are colorblind.