Tennessee (TN) CE-A, H High Voltage Electrical Contractor Practice Exam | Actual Questions and Answers | Latest Update | 100% Correct

1. Which NEC Article is specifically dedicated to equipment operating at more than 1000 volts? A. Article 110 B. Article 225 C. Article 490 D. Article 710 Answer: C. Article 490 Rationale: Article 490, "Equipment, Over 1000 Volts," covers the specific requirements for equipment, conductors, and systems operating above 1000 volts. Article 110 contains general requirements, Article 225 covers outside branch circuits, and Article 710 covers stand-alone systems. 2. According to the NEC, accessible (as applied to equipment) means capable of being reached for which of the following? A. Operation, renewal, and inspection only B. Operation, renewal, inspection, and maintenance C. Inspection and maintenance only D. Renewal and repair only Answer: B. Operation, renewal, inspection, and maintenance Rationale: NEC Article 100 definitions state that "Accessible (as applied to equipment)" means admitting close approach; not guarded by locked doors, elevation, or other effective means. It specifies it is for operation, renewal, inspection, and maintenance.3. What is the minimum working space depth for a 13.2kV system with exposed live parts on one side and no live parts on the other side (Condition 1)? A. 3 feet B. 4 feet C. 5 feet D. 6 feet Answer: C. 5 feet Rationale: Per NEC Table 110.34(A), for systems 2.1kV to 15kV, the minimum clear working space in front of electrical equipment is 5 feet for Condition 1 (exposed on one side, grounded on the other), 6 feet for Condition 2 (exposed on both sides), and 9 feet for Condition 3 (exposed on both sides with the operator between). 4. The minimum headroom of working spaces about service equipment, switchboards, panelboards, or motor control centers shall be how many feet? A. 5.5 ft B. 6.0 ft C. 6.5 ft D. 7.0 ft Answer: C. 6.5 ft Rationale: NEC 110.26(E) specifies that the minimum headroom of working spaces about electrical equipment is 6.5 feet (2.0 meters). No equipment associated with the electrical installation may be located in this headroom. 5. An identification plate for high-voltage equipment must include which of the following? A. Nominal voltage and phase B. Nominal voltage and available fault current C. Phase and frequency D. Available fault current and frequency Answer: B. Nominal voltage and available fault current Rationale: NEC 110.35 requires that high-voltage equipment (over 1000V) be marked with an identification plate listing the nominal operating voltage and the available fault current, or equivalent information, to inform personnel of potential hazards. 6. What is the primary purpose of grounding electrical systems and equipment? A. To improve power factor B. To limit voltage due to lightning, line surges, or unintentional contact C. To stabilize the system frequency D. To reduce energy consumption Answer: B. To limit voltage due to lightning, line surges, or unintentional contact Rationale: As stated in NEC 250.4(A)(1), the purpose of grounding is to limit voltagesimposed by lightning, line surges, or unintentional contact with higher-voltage lines and to stabilize the voltage to earth during normal operation. 7. A grounded conductor (neutral) of a secondary high-voltage system is required to be run to each service disconnecting means. This is primarily to: A. Provide a path for ground-fault current. B. Bond non-current-carrying metal parts. C. Provide a path for the load current. D. Maintain voltage stability. Answer: A. Provide a path for ground-fault current. Rationale: NEC 250.24(C) requires the grounded conductor (neutral) to be run to the service to provide a low-impedance path for ground-fault current to facilitate the operation of overcurrent devices. 8. The minimum size grounding electrode conductor for a high-voltage service with 500 kcmil phase conductors is: A. 2 AWG copper B. 1/0 AWG copper C. 2/0 AWG copper D. 3/0 AWG copper Answer: B. 1/0 AWG copper Rationale: For high-voltage systems, NEC 250.66, based on Table 250.66, is used. For service phase conductors of 500 kcmil (over 350, up to 600), the required grounding electrode conductor is 1/0 AWG copper or 3/0 AWG aluminum. 9. Which of the following is NOT a suitable grounding electrode? A. Metal underground water pipe B. Concrete-encased electrode (Ufer) C. A driven ground rod shorter than 8 feet D. The metal frame of a building Answer: C. A driven ground rod shorter than 8 feet Rationale: NEC 250.52(A)(5) specifies that driven ground rods must be at least 8 feet in length. Rods shorter than 8 feet do not meet the code requirement for a grounding electrode. 10. What is the maximum resistance requirement for a single made electrode (like a ground rod) if it is the sole grounding electrode? A. 15 ohms B. 20 ohms C. 25 ohms D. There is no maximum resistance for a single rod.Answer: D. There is no maximum resistance for a single rod. Rationale: NEC 250.53(A)(2) Exception states that a single rod, pipe, or plate electrode that does not have a resistance to ground of 25 ohms or less must be augmented by an additional electrode. The code does not mandate a specific resistance for a single electrode, but if it's over 25 ohms, you must add another