TENNESSEE (TN) CE-A, H HIGH VOLTAGE ELECTRICAL CONTRACTOR COMPLETE EXAM QUESTIONS AND 100% VERIFIED ANSWERS (PASS GUARANTEE)

TENNESSEE CE-A, H HIGH VOLTAGE ELECTRICAL CONTRACTOR




1. Q: What is the minimum burial depth for rigid metal conduit containing
600V circuits under a building? ANSWER 0 inches (no minimum burial
depth required under buildings per NEC Table 300.5)
2. Q: What is the maximum voltage allowed for high voltage systems
covered under NEC Article 490? ANSWER Over 1000 volts nominal (high
voltage is defined as over 1000V)
3. Q: What is the minimum working space depth required in front of
equipment operating at 2400V to ground with exposed live parts on one
side? ANSWER 4 feet (Condition 1, per NEC Table 110.34(A))
4. Q: What size equipment grounding conductor is required for a 400-
ampere circuit using copper conductors? ANSWER 3 AWG copper (per
NEC Table 250.122)
5. Q: What is the minimum height of working space for equipment
operating at 5000V? ANSWER 6.5 feet (per NEC 110.34(E))
6. Q: What is the maximum distance between supports for rigid metal
conduit? ANSWER 10 feet (per NEC Table 344.30(B)(2))
7. Q: What is the ampacity of 4/0 AWG THHN copper conductor at 75°C?
ANSWER 230 amperes (per NEC Table 310.16)
8. Q: What is the minimum size copper grounding electrode conductor for
a service with 500 kcmil conductors? ANSWER 1/0 AWG (per NEC Table
250.66)
9. Q: What is the minimum cover requirement for direct-buried cables
rated 600V in a trench under a street? ANSWER 24 inches (per NEC Table
300.5)

,10. Q: What is the maximum number of quarter bends allowed in a conduit
run between pull points? ANSWER Four quarter bends (360 degrees total)
per NEC 358.26
11. Q: What is the minimum separation required between high voltage
conductors over 22kV and ground in outdoor substations? ANSWER Per
NEC Table 110.34(E), minimum clearances must be maintained based on
voltage levels
12. Q: What color must the grounded conductor be for systems under
1000V? ANSWER White, gray, or three continuous white or gray stripes (per
NEC 200.6)
13. Q: What is the minimum bending radius for single conductor cables
rated 5kV to 35kV without lead sheath? ANSWER 12 times the diameter of
the conductor (per NEC Table 300.34)
14. Q: What is the required illumination level for service equipment areas?
ANSWER Not less than 300 lux (30 foot-candles) per NEC 110.26(D)
15. Q: What is the maximum allowable voltage drop for feeders and
branch circuits combined? ANSWER 5% (NEC recommends, not required)
16. Q: What is the minimum size copper conductor allowed for service
entrance conductors? ANSWER 8 AWG copper for overhead service (per
NEC 230.23(B))
17. Q: What temperature rating must be used when sizing conductors for
most terminations? ANSWER 75°C unless equipment is marked otherwise
(per NEC 110.14(C))
18. Q: What is the minimum depth of working space required for
equipment rated 13kV with exposed live parts on both sides? ANSWER 5
feet (Condition 2, per NEC Table 110.34(A))
19. Q: How often must ground resistance testing be performed on made
electrodes? ANSWER NEC does not specify frequency, but requires resistance
of 25 ohms or less
20. Q: What is the ampacity adjustment factor for 7-9 current-carrying
conductors in a raceway? ANSWER 70% (per NEC Table 310.15(C)(1))
Section 2: High Voltage Installation Requirements

, 21. Q: What is the minimum clearance required for high voltage overhead
service drops? ANSWER Varies by voltage; 18 feet minimum for up to 15kV
over residential areas
22. Q: What type of overcurrent protection is typically used for high
voltage circuits? ANSWER Fuses, circuit breakers, or current-limiting devices
rated for the voltage and current
23. Q: What is the minimum approach distance for qualified workers on
13.8kV energized parts? ANSWER Approximately 2 feet 2 inches depending
on specific conditions (OSHA 1926.1408)
24. Q: What is required for metal enclosures of high voltage equipment?
ANSWER Must be grounded, properly bonded, and provide adequate protection
25. Q: What is the minimum insulation resistance for high voltage cables
before energization? ANSWER Typically 1 megohm per 1000 volts, but
manufacturer specifications should be followed
26. Q: What is the purpose of a surge arrester in high voltage systems?
ANSWER To protect equipment from transient overvoltages by diverting surge
current to ground
27. Q: What is the minimum working space width in front of high voltage
equipment? ANSWER 3 feet or width of equipment, whichever is greater (per
NEC 110.34(A))
28. Q: What is required for doors providing access to high voltage rooms?
ANSWER Must be equipped with panic hardware and open in the direction of
egress
29. Q: What is the maximum allowable temperature rise for transformer
oil under full load? ANSWER Typically 65°C above ambient, per IEEE
standards
30. Q: What is the minimum separation distance between high voltage
buses operating at 15kV? ANSWER Determined by NEC Table 110.34(E)
based on voltage and conditions
31. Q: What type of grounding is required for high voltage transformer
neutrals? ANSWER Solidly grounded, impedance grounded, or ungrounded
based on system design
32. Q: What is the minimum mechanical protection required for
underground high voltage cables? ANSWER Concrete encasement or
equivalent protection where subject to physical damage