CET Governor & Overspeed Protection 2 — Questions and Answers
Question 1: What ASME A17.1 code section governs governor tripping speeds for traction elevators?
- Section 2.18 (Correct answer)
- Section 3.14
- Section 2.17
- Section 4.2
Correct answer: Section 2.18
ASME A17.1 Section 2.18 specifies the requirements for governor tripping speeds on traction elevators.
Question 2: On a dual-overspeed governor, the first tripping speed typically activates the:
- Safety device on the car
- Brake on the machine
- Emergency stop switch (Correct answer)
- Buffer engagement
Correct answer: Emergency stop switch
The first (lower) tripping speed on a dual-overspeed governor activates the emergency stop switch to cut power and apply the brake.
Question 3: Which type of governor rope is required for use with elevator governors per ASME A17.1?
- Fiber core wire rope
- Independent wire rope core (IWRC) (Correct answer)
- Chain drive linkage
- Synthetic fiber rope
Correct answer: Independent wire rope core (IWRC)
ASME A17.1 requires independent wire rope core (IWRC) governor ropes for their superior strength and resistance to crushing.
Question 4: What happens to the governor rope tension when the car overspeeds and the governor trips?
- Tension decreases to zero
- Tension increases as the rope is gripped (Correct answer)
- Tension remains constant
- Tension reverses direction
Correct answer: Tension increases as the rope is gripped
When the governor trips and grips the rope, tension in the governor rope increases, pulling the safety linkage to engage the car safeties.
Question 5: A governor that is set to trip at too low a speed relative to rated speed would most likely cause:
- Safeties engaging during normal operation (Correct answer)
- Increased motor heating
- Rope slippage on drive sheave
- Hydraulic pressure buildup
Correct answer: Safeties engaging during normal operation
A governor tripping speed set too close to rated speed may cause nuisance safety engagements during normal elevator operation.
Question 6: The governor sheave diameter on a traction elevator must comply with requirements based on:
- The diameter of the governor rope (Correct answer)
- The car weight
- The rated load capacity
- The hoistway height
Correct answer: The diameter of the governor rope
Governor sheave diameter must meet a minimum ratio to the governor rope diameter as specified in ASME A17.1 to prevent rope fatigue.
Question 7: On an elevator with a counterweight safety, what governs the counterweight safety engagement?
- A separate governor dedicated to the counterweight (Correct answer)
- The car governor rope
- A hydraulic pressure switch
- The machine brake
Correct answer: A separate governor dedicated to the counterweight
When counterweight safeties are required, a separate governor rope and governor assembly dedicated to the counterweight must be provided.
CET Governor & Overspeed Protection 2
What ASME A17.1 code section governs governor tripping speeds for traction elevators?