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Electrical Ultimate Exam
Question 1. According to the Florida Building Code Chapter 30, what is the minimum required illumination level for a machine-room elevator control panel? A) 5 lux B) 10 lux C) 20 lux D) 30 lux Answer: C Explanation: FBC 30.2.2 mandates a minimum of 20 lux (2 foot-candles) at the control panel to ensure safe operation and maintenance. Question 2. In ASME A17.1, which device is required to prevent elevator operation when phase reversal occurs on a three-phase supply? A) Ground fault interrupter B) Phase-loss relay C) Phase-reversal relay D) Over-current protective device Answer: C Explanation: A phase-reversal relay detects abnormal phase sequence and trips the power, protecting motor and control circuitry. Question 3. NEC Article 620 §620.11 requires a dedicated disconnecting means for the elevator. Where must this disconnect be located? A) Inside the car top operating station (CTOS) B) At the elevator machine-room entrance C) Within the hoistway pit D) On the main service panel only Answer: B Explanation: The primary disconnect must be readily accessible at the machine-room entrance to allow quick isolation of power.
Electrical Ultimate Exam
Question 4. When calculating feeder size for an elevator motor, NEC 620 §620.71 permits a demand factor of 0.5 for the first 75 kW of load. What is the demand factor for the next 25 kW? A) 0. B) 0. C) 0. D) 0. Answer: B Explanation: NEC 620.71 provides a step-up demand factor of 0.7 for the load portion exceeding 75 kW up to 100 kW. Question 5. Which of the following conductor types is not permitted inside a hoistway according to NEC 620.23? A) THHN in rigid metal conduit B) MC cable with steel armor C) NM-B cable D) XLPE-insulated single-conductor cable in PVC conduit Answer: C Explanation: NM-B (Romex) is prohibited in hoistways because it lacks the required fire-resistance and mechanical protection. Question 6. The ASME A17.1 safety chain requires the pit stop switch to be positioned no farther than what distance from the pit floor? A) 12 inches B) 24 inches C) 36 inches D) 48 inches Answer: B Explanation: The pit stop switch must be within 24 inches of the pit floor to ensure immediate activation when the car contacts the pit.
Electrical Ultimate Exam
Question 10. Which NEC article governs the installation of emergency lighting for elevator cars? A) 700 – Emergency Systems B) 620 – Elevators C) 210 – Branch Circuits D) 410 – Luminaires Answer: B Explanation: NEC 620 includes requirements for emergency car lighting, battery backup, and transfer switches. Question 11. In a PLC-based elevator controller, which I/O module type is used to monitor door-lock contacts? A) Analog input module B) Digital input module C) Pulse-width modulation output module D) Relay output module Answer: B Explanation: Door-lock contacts are binary (closed/open) signals, requiring a digital input module. Question 12. The ASME A17.1 fire service operation Phase II requires which of the following actions when the fire service switch is activated? A) Immediate full-speed descent to the lobby B) Disable all car-call functions and enable in-car fire service panel C) Shut down the motor and energize the brakes only D) Bypass all safety interlocks Answer: B Explanation: Phase II provides in-car fire service controls, disabling normal operation while allowing fire-fighter control of the car.
Electrical Ultimate Exam
Question 13. What is the maximum allowable voltage drop for feeder conductors feeding an elevator motor, as recommended by the NEC? A) 2 % B) 3 % C) 5 % D) 10 % Answer: B Explanation: NEC 210.19(A)(1) recommends a maximum of 3 % voltage drop for feeders to ensure motor performance. Question 14. Which of the following is the correct method for testing a pit illumination circuit for proper operation? A) Measure voltage at the pit fixture with a multimeter while the car is stationary B) Verify illumination level of at least 5 lux using a light meter when the car is in motion C) Ensure the pit switch trips when the car reaches the pit floor, then check illumination D) Use a continuity tester on the pit wiring only Answer: C Explanation: The pit stop switch must trip and illuminate the pit when the car contacts the pit floor; this verifies both safety and lighting function. Question 15. When performing lockout/tagout on an elevator’s primary disconnect, which of the following is required by OSHA 1910.147? A) Only a lock is needed, tags are optional B) Both a lock and a tag must be applied to each energized point C) Tagging is sufficient if a lock cannot be applied D) No lockout is needed if the disconnect is in a locked cabinet Answer: B Explanation: OSHA requires both a lock and a tag on each energy isolation point to ensure proper LOTO compliance.
Electrical Ultimate Exam
Question 19. Which of the following statements about the elevator’s emergency battery backup is incorrect according to ASME A17.1? A) Batteries must be able to supply full car lighting for at least 90 seconds B) Batteries must be tested monthly for voltage and capacity C) Battery banks must be located in a fire-rated enclosure D) Batteries may be installed in the car top operating station without fire protection Answer: D Explanation: Batteries must be housed in fire-rated enclosures; installing them in the CTOS without protection violates the code. Question 20. The NEC permits which of the following conduit materials for routing power conductors in a machine-room that is exposed to corrosive environments? A) Rigid PVC conduit B) Rigid steel conduit with a zinc coating C) Flexible metal conduit (FMC) D) Non-metallic raceway (EMT) Answer: B Explanation: Rigid steel conduit with a zinc coating provides corrosion resistance suitable for harsh machine-room conditions. Question 21. Which ASME A17.1 requirement ensures that an elevator cannot move when either hoistway or car doors are open? A) Phase-loss detection circuit B) Door-lock interlock circuit C) Over-speed governor switch D) Emergency stop button Answer: B Explanation: The door-lock interlock circuit disables motor power when any door is not securely closed.
Electrical Ultimate Exam
Question 22. In a dual-system elevator (hydraulic + traction backup), which code section governs the coordination of the two power sources? A) NEC 210.4 – Multi-wire Branch Circuits B) NEC 620.9 – Multiple Power Sources C) ASME A17.1 §4.5 – Redundant Power Systems D) FBC 30.4 – Elevator Power Redundancy Answer: B Explanation: NEC 620.9 addresses the installation and coordination of multiple power sources for elevators. Question 23. Which of the following is the correct procedure for verifying the operation of a car-top operating station (CTOS) during maintenance? A) Disconnect the CTOS and operate the car from the main panel only B) Apply a temporary lockout on the primary disconnect and test CTOS functions at reduced speed C) Use the CTOS to move the car at full speed without any lockout D) Remove all safety interlocks before using the CTOS Answer: B Explanation: The CTOS may be used during maintenance only after locking out the primary disconnect and operating at a reduced, safe speed. Question 24. What is the minimum rating for a ground-fault protective device (GFPD) on a dedicated elevator lighting circuit per NEC 620.91? A) 15 A B) 20 A C) 30 A D) 40 A Answer: B Explanation: NEC 620.91 requires a 20 A GFPD for dedicated lighting circuits to protect against ground faults.
Electrical Ultimate Exam
Question 28. In a relay-logic elevator control, which relay typically provides the “hold” function for the motor starter? A) Auxiliary relay K B) Main contactor C) Over-current relay D) Safety interlock relay Answer: A Explanation: An auxiliary relay (often labeled K1) maintains the control circuit closed after the start button is released. Question 29. When retrofitting an older DC-motor elevator to an AC-induction motor, which code provision must be reviewed to ensure compliance? A) NEC 620.12 – Motor Type Restrictions B) ASME A17.1 §5.6 – Motor Conversion Requirements C) FBC 30.3 – Replacement of Electrical Equipment D) NEC 210.8 – GFCI Protection Answer: B Explanation: ASME A17.1 §5.6 specifically addresses requirements when converting motor types in existing elevators. Question 30. Which of the following best describes the purpose of a “phase-loss relay” in an elevator system? A) Detects open-circuit on any phase and shuts down the motor B) Balances load between phases during operation C) Provides harmonic filtering for VFDs D) Controls the door-lock interlock circuit Answer: A Explanation: A phase-loss relay monitors each phase; loss of any phase triggers a trip to protect the motor and control gear.
Electrical Ultimate Exam
Question 31. The NEC permits the use of which of the following for grounding the metal conduit that serves as a grounding path for elevator wiring? A) No grounding required if conduit is PVC B) A separate grounding conductor of at least 12 AWG copper C) The metal conduit itself, provided it is continuous and bonded at each end D) Only a grounding electrode rod at the base of the hoistway Answer: C Explanation: Metal conduit can serve as an effective equipment grounding conductor if it remains continuous and is bonded at each termination. Question 32. Which NEC requirement specifies that elevator control panels must be equipped with a “disconnecting means” that is “readily accessible”? A) 620.11(A) – Location of Disconnect B) 210.4(B) – Multi-wire Branch Circuits C) 250.68(A) – Grounding Electrode Conductor Connection D) 430.102 – Motor Disconnecting Means Answer: A Explanation: NEC 620.11(A) mandates that the disconnecting means be readily accessible to facilitate safe isolation. Question 33. During a periodic inspection, an inspector notes that the car-top operating station (CTOS) wiring is routed through a non-metallic raceway. Which code violation does this represent? A) Violation of NEC 620.23 – Conduit Material in Hoistways B) Violation of ASME A17.1 – CTOS Wiring Protection C) Violation of NEC 300.22 – Protection of Conductors in Raceways D) No violation; non-metallic raceway is permitted Answer: A Explanation: NEC 620.23 restricts non-metallic raceways in hoistways and machine rooms; CTOS wiring must be in approved metal conduit.
Electrical Ultimate Exam
Question 37. The ASME A17.1 safety chain includes the “final limit switch.” What is the primary purpose of this switch? A) To initiate door closing when the car reaches the landing B) To stop the motor when the car reaches the top or bottom landing C) To provide a backup power source for the car lights D) To detect over-speed conditions during travel Answer: B Explanation: The final limit switch detects the car’s arrival at a landing and shuts down the motor to stop movement. Question 38. Which of the following is a required feature of an elevator’s fire-service recall circuit per FBC 30.5? A) Automatic activation of the emergency brake only B) Ability to recall the car to the main lobby without manual input C) Activation of a dedicated fire-service transformer D) Isolation of all non-essential loads before recall Answer: B Explanation: Fire-service recall must automatically bring the car to a designated floor (usually the lobby) without requiring passenger input. Question 39. When performing a megger test on an elevator’s control cable, the acceptable insulation resistance value for a 500-ft run is at least: A) 1 MΩ B) 10 MΩ C) 100 MΩ D) 500 MΩ Answer: B Explanation: NEC recommends a minimum of 10 MΩ for control cables up to 500 ft to ensure adequate insulation.
Electrical Ultimate Exam
Question 40. According to NEC 620.31, the grounding conductor for an elevator must be sized based on the largest of which two factors? A) Voltage rating of the feeder and number of conductors B) Ampacity of the feeder and the rating of the protective device C) Length of the run and ambient temperature D) Number of floors served and motor horsepower Answer: B Explanation: The grounding conductor size is based on the larger of the feeder’s ampacity or the rating of the over-current protective device. Question 41. Which of the following is the correct NEC-approved method for protecting an elevator’s control wiring from physical damage in the hoistway? A) Installing the wiring in a PVC conduit buried in concrete B) Using flexible metal conduit (FMC) with a minimum 1/2-inch trade size C) Running the wiring loose and secured with zip ties every 12 inches D) Placing the wiring in a non-metallic raceway without supports Answer: B Explanation: Flexible metal conduit provides mechanical protection and is accepted for control wiring in hoistways. Question 42. In an elevator equipped with a regenerative VFD, which component is required to safely dissipate excess energy during a downhill operation? A) Line reactor B) Dynamic brake resistor C) Surge protective device D) Capacitor bank Answer: B Explanation: A dynamic brake resistor absorbs regenerated energy and converts it to heat, protecting the VFD.
Electrical Ultimate Exam
Question 46. Which of the following is the proper NEC-approved method for grounding a metallic conduit that serves as the equipment grounding conductor for an elevator? A) Apply a grounding clamp at each conduit bend B) Bond the conduit at each termination point with a grounding screw or clamp C) Install a separate grounding wire inside the conduit D) No grounding is needed if the conduit is continuous Answer: B Explanation: NEC requires bonding at each termination to ensure the conduit provides a reliable grounding path. Question 47. When sizing a feeder for a dual-machine-room elevator (two separate machine rooms), which factor must be considered per NEC 620.71? A) The sum of both machine-room loads without demand factor B) The larger of the two loads, applying the demand factor only once C) The average of the two loads, then applying the demand factor D) Each machine-room feeder is sized independently, no combined calculation required Answer: B Explanation: NEC 620.71 allows the larger load to dictate feeder size, applying the demand factor only once for the combined system. Question 48. The NEC requires that all elevator control panels be equipped with a label indicating which of the following? A) Manufacturer’s warranty period B) Maximum allowable temperature for operation C) Voltage rating, phase, and disconnect location D) Number of floors served Answer: C Explanation: Labels must identify voltage, phase, and disconnect location to aid safe operation and maintenance.
Electrical Ultimate Exam
Question 49. Which of the following devices is used to prevent an elevator from moving when the hoistway door is open? A) Phase-loss relay B) Door-lock interlock switch C) Over-speed governor D) Emergency stop button Answer: B Explanation: The door-lock interlock ensures that power is removed when any hoistway door is not securely closed. Question 50. In a hydraulic elevator, the pump motor is typically protected by a thermal overload relay set to trip at what percentage of the motor’s full-load current? A) 80 % B) 100 % C) 115 % D) 150 % Answer: C Explanation: Thermal overload relays are commonly set to 115 % of full-load current to allow short overloads while protecting the motor. Question 51. Which ASME A17.1 requirement specifies the minimum clearance between the elevator’s emergency brake assembly and any combustible material? A) 1 inch B) 3 inches C) 6 inches D) 12 inches Answer: C Explanation: A 6-inch clearance is required to prevent ignition of nearby combustible materials.
Electrical Ultimate Exam
Question 55. Which of the following best describes the function of a traveling cable in an elevator system? A) Supplies power to the motor from the main service panel B) Carries low-voltage signals and power between the car and the machine room while moving with the car C) Provides a permanent grounding path for the car frame D) Acts as a fire-rated protective conduit for the hoistway Answer: B Explanation: The traveling cable supplies power and signals to the car and moves with it, allowing continuous operation. Question 56. According to ASME A17.1, what is the minimum required voltage for the car-top operating station (CTOS) power supply? A) 120 V AC, 1 phase B) 208 V AC, 3 phase C) 240 V DC D) 480 V AC, 3 phase Answer: A Explanation: The CTOS is typically powered by a standard 120 V AC, single-phase supply for control and illumination. Question 57. Which NEC article requires that all elevator control circuits be equipped with a lockout/tagout (LOTO) procedure documented in the maintenance manual? A) 620.11 – Disconnecting Means B) 300.4 – Protection Against Physical Damage C) 210.5 – Branch Circuit Ratings D) 430.102 – Motor Disconnecting Means Answer: A Explanation: NEC 620.11 emphasizes the need for documented LOTO procedures for disconnecting means on elevator systems.
Electrical Ultimate Exam
Question 58. When installing a new VFD for a traction elevator, the NEC requires a dedicated grounding electrode for the VFD enclosure. What size copper conductor is minimum for this grounding electrode? A) 6 AWG B) 8 AWG C) 10 AWG D) 12 AWG Answer: B Explanation: NEC 250.118 requires at least 8 AWG copper for grounding electrodes of VFD enclosures. Question 59. In an elevator’s emergency operation, the battery backup must be capable of providing power for at least how many seconds after loss of the main supply? A) 30 seconds B) 60 seconds C) 90 seconds D) 120 seconds Answer: C Explanation: ASME A17.1 specifies a minimum of 90 seconds of emergency power for lighting and communication. Question 60. Which of the following is the primary purpose of a phase-reversal relay in an elevator motor circuit? A) To balance load between phases B) To prevent motor damage from incorrect phase sequence C) To reduce harmonic distortion D) To provide a backup power source Answer: B Explanation: The relay detects and prevents operation when the three-phase supply is connected in the wrong sequence.
