CET CET Machine Room & Pit Equipment 1 — Questions and Answers
Question 1: What is the minimum headroom clearance required above elevator machine room equipment per ASME A17.1?
- 6 feet
- 7 feet (Correct answer)
- 8 feet
- 9 feet
Correct answer: 7 feet
ASME A17.1 requires a minimum headroom clearance of 7 feet (2134 mm) above the working surfaces in machine rooms.
Question 2: Which device in the elevator pit is used to slow and stop the car or counterweight in the event of an overspeed descent?
- Oil buffer
- Car safety device (Correct answer)
- Pit stop switch
- Bottom limit switch
Correct answer: Car safety device
The car safety device (safeties) clamps onto the guide rails to stop the car when the governor detects an overspeed condition.
Question 3: What is the purpose of the pit stop switch on a traction elevator?
- Stops the car at the lowest landing
- De-energizes the elevator for pit maintenance (Correct answer)
- Activates the oil buffer
- Resets the safety circuit after overspeed
Correct answer: De-energizes the elevator for pit maintenance
The pit stop switch is a red emergency stop switch that cuts power to the elevator to allow safe maintenance work inside the pit.
Question 4: What is the minimum pit depth required for most standard traction elevators under ASME A17.1?
- 12 inches
- 24 inches
- 48 inches (Correct answer)
- 60 inches
Correct answer: 48 inches
ASME A17.1 typically requires a minimum pit depth of 48 inches (1219 mm) for standard traction elevators to accommodate buffers and clearances.
Question 5: What type of lighting is required in an elevator machine room?
- Emergency lighting only
- Permanent artificial illumination of at least 19 foot-candles (Correct answer)
- Natural lighting with a window
- Portable task lighting only
Correct answer: Permanent artificial illumination of at least 19 foot-candles
ASME A17.1 requires permanent artificial lighting providing a minimum of 19 foot-candles (200 lux) at the floor level in machine rooms.
Question 6: What is the function of the oil buffer in the elevator pit?
- Lubricates the guide rails
- Absorbs kinetic energy to decelerate the car or counterweight (Correct answer)
- Stores hydraulic fluid for the drive system
- Provides a cushion for normal floor-level stops
Correct answer: Absorbs kinetic energy to decelerate the car or counterweight
Oil buffers absorb and dissipate the kinetic energy of an elevator car or counterweight running into them, preventing sudden impact.
CET CET Machine Room & Pit Equipment 1
What is the minimum headroom clearance required above elevator machine room equipment per ASME A17.1?