216 Questions with 100% Correct
Answers – COMPLETE SOLUTION
Section 1: Safety & Codes
1. Q: What is the primary safety code governing elevator installation and maintenance in
the United States?
A: ASME A17.1/CSA B44 Safety Code for Elevators and Escalators.
2. Q: Before working on an elevator, what is the first and most critical safety action a
mechanic must take?
A: Lock out and tag out (LOTO) the main line disconnect.
3. Q: According to A17.1, what is the minimum required headroom in the elevator
hoistway above the top landing?
A: The minimum headroom is typically the greater of 1) the stopping distance of the car
+ 48 inches, or 2) 11.5 feet (138 inches). Specific rules apply based on speed.
4. Q: What device prevents an elevator car from moving while the hoistway door is
unlocked or open?
A: The door interlock.
5. Q: What is the minimum clearance required between the car sill and hoistway face when
the car is level with a landing?
A: A maximum of 1.25 inches.
Section 2: Electrical Principles
6. Q: In a three-phase power system, what is the typical phase separation in degrees?
A: 120 degrees.
7. Q: What is the purpose of a "ground fault circuit interrupter" (GFCI) on a worksite?
A: To quickly break the circuit if it detects a current imbalance between the hot and
neutral wires, preventing electrocution.
8. Q: What does the "service factor" on an AC motor nameplate indicate?
A: The amount of overload a motor can handle without damage under defined
conditions.
, 9. Q: Which electrical device is used to control a large current with a smaller current?
A: A relay or contactor.
10. Q: What is the unit of electrical capacitance?
A: The Farad.
11. Q: What is the purpose of a "bridge rectifier" in an elevator control circuit?
A: To convert alternating current (AC) to direct current (DC).
12. Q: A voltmeter is always connected in __ with the circuit.
A: Parallel.
Section 3: Motors & Generators
13. Q: In a DC motor, what component reverses the current in the armature to maintain
rotation?
A: The commutator and brushes.
14. Q: What type of AC motor is most commonly used for modern VVVF (Variable Voltage
Variable Frequency) elevator traction machines?
A: A 3-phase AC induction motor.
15. Q: What is "synchronous speed" in an AC induction motor?
A: The speed of the motor's rotating magnetic field, determined by the frequency of the
power supply and the number of poles.
16. Q: What is the primary purpose of the "counter-electromotive force" (CEMF) in a DC
motor?
A: It limits the armature current as the motor speeds up.
Section 4: Machine Room & Sheaves
17. Q: What is the primary function of the elevator "sheave" or "traction sheave"?
A: To transmit motion from the machine to the elevator ropes via friction.
18. Q: What is the minimum required diameter of a traction sheave for a steel wire rope?
A: A17.1 requires a minimum of 40 times the diameter of the rope.
19. Q: What does a "1:1" roping configuration mean?
A: The car and counterweight travel at the same speed as the rope; the sheave is directly
overhead.
, 20. Q: What is a "deflector sheave" used for?
A: To change the direction of the hoist ropes, often to increase the distance between the
car and counterweight or to accommodate a basement machine room.
Section 5: Brakes & Controls
21. Q: What type of brake is required on all traction and winding-drum elevator machines?
A: An electrically released, mechanically applied brake (spring-applied, electromagnetically
released).
22. Q: When power is removed from the machine, the brake must engage. This is known as
a __ brake.
A: Fail-safe.
23. Q: What is the function of the "governor" in an elevator system?
A: To detect overspeed of the car in the down direction and initiate the safety activation.
24. Q: Which safety device stops the elevator car by gripping the guide rails?
A: The safety (or "car safeties").
Section 6: Hydraulic Elevators
25. Q: What is the main component that directly lifts the elevator car in a hydraulic elevator?
A: The piston (ram).
26. Q: What safety device must be installed on the oil line between the valve and the
cylinder to prevent uncontrolled descent?
A: A rupture valve (or piping rupture valve).
27. Q: What is the purpose of the "bypass valve" on a hydraulic elevator?
A: To manually lower the car during maintenance or in case of power failure.
28. Q: In a hydraulic elevator, what component controls the flow of oil to the cylinder to
regulate speed?
A: The flow control valve (often part of the valve manifold).
Section 7: Doors & Operations
29. Q: What device physically locks the hoistway door and is only released when the car is at the
landing?
A: The door interlock.
, 30. Q: What is the minimum required average closing door force for power-operated
passenger elevator doors?
A: Not more than 30 pounds.
31. Q: What safety device reopens a power-operated car door if an obstruction is detected?
A: The reopening device (e.g., door photocell, safety edge).
32. Q: What is the maximum allowable horizontal opening force required to reopen a closed
passenger elevator door?
A: Not more than 50 pounds.
Section 8: Governor & Safeties
33. Q: At what percentage of rated speed must the governor trigger the overspeed switch?
A: Not less than 95% and not more than 115% of the governor tripping speed.
34. Q: What is the device called that is attached to the car frame and is actuated by the
governor rope to apply the car safeties?
A: The governor rope tension sheave assembly, or more specifically, the safety releasing
carrier.
35. Q: On a Type B (Instantaneous) safety, what is the maximum permissible stopping
distance (in G's)?
A: It must not exceed a deceleration of 32.2 ft/s² (1 G).
Section 9: Buffers & Springs
36. Q: What is the purpose of an elevator buffer?
A: To bring a descending car or counterweight to a gradual stop at the limits of travel.
37. Q: What two main types of buffers are recognized by A17.1?
A: Energy accumulation (spring) and energy dissipation (oil/oil hydraulic).
38. Q: For a hydraulic elevator, what type of buffer is required at the bottom of the
hoistway?
A: A Type A buffer (spring or equivalent) is typically required for piston-supported cars.
Section 10: Counterweights & Guide Rails
39. Q: What is the typical weight of a passenger elevator counterweight as a percentage of the
car's rated load?
A: Approximately 40-50% of the car weight + rated load.