Equipment — Texas Master Practice Questions

Exam tip

Always round up to the next standard size when calculating overcurrent protection.

Why B is correct

According to 210.3(B), the overcurrent protection for 120V lighting circuits must not be less than 125% of the rating of the service. Therefore, 200A x 1.25 = 250A. The next standard size above 250A is 125A.

Exam tip

Always refer to the specific voltage and service type for the correct grounding conductor size.

Why B is correct

According to 250.66(A)(1), the grounding electrode conductor must be not less than 8 AWG for a 480V, 3-phase, 4-wire service.

Exam tip

Always refer to Table 318.17 for the allowable fill of raceways based on their size and conductor sizes.

Why B is correct

According to 318.17(A), the allowable fill for a 3-inch diameter raceway with 12 AWG conductors is 70%.

Exam tip

Use Table 310.15(B)(16) to determine the minimum conductor size for a given current and run length.

Why C is correct

According to 310.15(B)(16), for a 100A circuit, the minimum conductor size is 250 kcmil for a 100-foot run.

Exam tip

Always refer to the specific requirements for bonding jumpers based on the type of structure and grounding electrode system.

Why B is correct

According to 250.94(A)(1), the minimum size of the bonding jumper is 8 AWG for a metal frame structure.

Exam tip

Ensure the AFCI is rated for the same current as the circuit it is intended to protect.

Why A is correct

According to 210.12(A)(2), the AFCI must be rated at the same current as the circuit it protects, which in this case is 15A.