Question

A single overload device protects a continuous duty 3 HP, 208-volt motor with a nameplate rating of 19.2 amperes and a service factor of 1.15. The overload will be selected to trip at how many amperes?

1. 21.50 amperes
2. 22.08 amperes
3. 23.37 amperes
4. 24.00 amperes

Answer 1

The overload device for a 3 HP, 208-volt motor with a 19.2 ampere nameplate rating and a service factor of 1.15 should be selected to trip at 22.08 amperes.

Step-by-step explanation:

The student's question involves selecting the correct overload device for a continuous duty 3 HP, 208-volt motor with a nameplate rating of 19.2 amperes and a service factor of 1.15. To determine the current at which the overload device should trip, we use the formula:

Itrip = Nameplate Current × Service Factor

By multiplying the nameplate rating (19.2 amperes) by the service factor (1.15), we get:

Itrip = 19.2 A × 1.15 = 22.08 amperes

Therefore, the overload device should be selected to trip at 22.08 amperes, which corresponds to option 2.