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Transformers & Special Locations
2. What size primary fuse is required to protect a 5 kVA, 208 V, 3(I) transformer?
A. 13.5 A
B.20A
C. 17.5 A
D.15 A
3. What is the maximum size fuse that may be used to protect a 60 kVA, nonsupervised transformer having a 4,160 V primary and 5% impedance?
A.25A
B.20A
C. 35 A
D. 30A
4. Two electricians are discussing hazardous locations. Electrician A says that a motor installed in a Class II, Division 2 can be totally enclosed and fan cooled. Electrician B says that the installation requirements for motor controllers in a Class 3 location can be more relaxed than for a Class I location. Which of the following statements is correct?
A. Both electricians are correct.
B. Only Electrician A is correct.
C. Neither electrician is correct.
D. Only Electrician B is correct.
6. In Class II, Division 2, conditions fuses, switches, circuit breakers, and similar devices must be installed in enclosures that are
A. dust tight.
B. vapor proof.
C. airtight.
D. watertight.
7. Which of the following is not a requirement for receptacles located at patient bed sites?
A. GFCI-Type
B. Minimum of eight per patient bed site
C. Listed as hospital grade
D. Tamper resistant for pediatric locations
8. According to the NEC, which of the following transformer types is not required to be installed in readily accessible space?
A. LFLI type, 600 V or less
B. Dry type, 35 kV or less
C. Dry type, 600 V or less
D. LFLI type, 600 V or less
9. Which of the following should not be connected to the life safety branch circuit within a health care facility?
A. Elevator
B. Nurse call system
C. Stairway lighting
D. Alarm system
10. A hazardous location in which flammable gases or vapors exist in sufficient quantities to cause an explosion, as defined by the NEC?
A. Class II
B. Class I
C. Class III
D. Unclassified
11. Which of the following is not a general provision requirement for transformers per the NEC?
A. Ventilation that prevents temperature rise in excess of the transformer rating
B. Lockable disconnecting means for remote locations
C. Primary and secondary voltage rating on nameplate
D. Temperature class marking for oil-insulated transformers
12. Two electricians are discussing transformer installations. Electrician A says that there is no size requirement for the door sill of a transformer vault as long as the sill would contain the oil from the largest transformer. Electrician B says that the AHJ can require fire rating of three hours for vault doors on an exterior wall. Which of the following statements is correct?
A. Both electricians are correct.
B. Only Electrician B is correct.
C. Neither electrician is correct.
D. Only Electrician A is correct.
13. To properly protect the 4160 V primary of a 100 kVA, 3, nonsupervised transformer with 8 percent impedance, which of the following fuse sizes would you select?
A.40A
B. 50 A
C.45A
D. 60A
14. According to the NEC, which of the following protection techniques is permitted for Class I, Division 1 or 2 Locations?
A. Explosion-proof equipment
B. Dust-tight equipment
C. Nonincendive equipment
D. Hermetically sealed equipment
16. Which of the following is a NEC violation for wiring installed in a place of assembly?
A. Temporary wiring not protected by GFCis
B. Permanent wiring using AC cable containing an insulated EGC
C. Permanent wiring in nonmetallic raceway encased by one inch of concrete
D. Temporary wiring laid directly on the floor
17. With the exception of class 2 or class 3 transformers, if the disconnecting means for a transformer is not in sight of the transformer, the disconnecting means is required to be
A. moisture resistant.
B. lockable.
C. weatherproof.
D. bonded.
18. What is the T Code for equipment having a maximum surface temperature of 392°F?
A. T4
B. T3
C.T3A
D. T4A
19. To be in compliance with the NEC, transformer vaults must have a fire-resistance rating of __ _ hours and concrete floors that are at least inches thick, unless protected by automatic sprinkler systems.
A.3,4
B. 2, 3
c. 1, 3
D.4,4
20. Two electricians are discussing guarding requirements for transformers. Electrician A says that a warning sign indicating the operating voltage of live parts on a transformer is required if the live parts are exposed. Electrician B says that dry-type transformers can be installed without an enclosure. Which of the following statements is correct?
A. Only Electrician A is correct.
B. Both electricians are correct.
C. Only Electrician B is correct.
D. Neither electrician is
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