Licensed Electrical Contractor Electrical Contractor Electrical System Design & Installation 3

Question 1

When sizing a transformer for a new commercial installation, which NEC article governs the installation requirements for transformers rated 1000 volts or less?

Accepted Answer

Article 450

Answer

Article 480

Answer

Article 440

Answer

Article 430

Question 2

For a parallel conductor installation using two sets of 500 kcmil conductors per phase, what is the NEC requirement for conductor arrangement?

Accepted Answer

Each phase must have the same length, type, and termination method

Answer

Conductors may be different lengths if total ampacity matches

Answer

Only the same insulation type is required

Answer

No special requirements apply to parallel conductors

Question 3

What is the NEC-required working space clearance in front of a 480V electrical panel?

Accepted Answer

3 feet

Answer

2.5 feet

Answer

4 feet

Answer

3.5 feet

Question 4

When designing an emergency power system for a commercial building, which NEC article specifically covers emergency system requirements?

Accepted Answer

Article 700

Answer

Article 701

Answer

Article 702

Answer

Article 708

Question 5

In a commercial electrical design, what is the minimum circuit ampacity required for a continuous load per NEC Section 210.20?

Accepted Answer

125% of the continuous load

Answer

100% of the continuous load

Answer

115% of the continuous load

Answer

150% of the continuous load

Question 6

What is the maximum number of disconnecting means permitted for a single service per NEC Section 230.71?

Accepted Answer

6

Answer

4

Answer

3

Answer

8