CET Governor & Overspeed Protection 3 — Questions and Answers
Question 1: What is the purpose of the governor rope tension device (tensioning sheave)?
- To maintain proper rope tension and prevent slack (Correct answer)
- To increase governor tripping speed
- To act as a secondary brake
- To guide the rope around the car frame
Correct answer: To maintain proper rope tension and prevent slack
The governor rope tensioning sheave keeps the rope taut so the governor can accurately sense car speed and grip the rope when tripping.
Question 2: Which condition would require immediate replacement of a governor rope?
- Minor surface oxidation
- Six broken wires in one lay length (Correct answer)
- One broken wire in any strand
- Slight kinking from installation
Correct answer: Six broken wires in one lay length
ASME A17.1 requires governor rope replacement when six or more broken wires are found in one lay length of the rope.
Question 3: What is the minimum factor of safety required for a governor rope under ASME A17.1?
- 5
- 8
- 10 (Correct answer)
- 12
Correct answer: 10
ASME A17.1 requires a minimum factor of safety of 10 for governor ropes based on breaking strength versus maximum rope load.
Question 4: On a centrifugal governor, what component physically grips the governor rope when the tripping speed is reached?
- Flyweights
- Jaws or gripper (Correct answer)
- Tension spring
- Ratchet pawl
Correct answer: Jaws or gripper
When the flyweights expand outward from centrifugal force, they actuate jaws or grippers that clamp onto the governor rope.
Question 5: A governor that has been tripped during a safety test must be manually reset before returning the elevator to service because:
- The gripper jaws remain locked on the rope until manually released (Correct answer)
- The motor overloads are tripped
- The buffer switches need resetting
- The control circuit fuses have blown
Correct answer: The gripper jaws remain locked on the rope until manually released
After a governor trip, the jaw mechanism remains engaged and must be manually reset to release the governor rope and allow elevator operation.
Question 6: How is governor tripping speed verified during a periodic test?
- By measuring governor sheave RPM with a tachometer at rated speed
- By overspending the car until the governor trips and recording car speed (Correct answer)
- By checking the flyweight spring tension only
- By reviewing the manufacturer's nameplate only
Correct answer: By overspending the car until the governor trips and recording car speed
Governor tripping speed is verified by running the elevator at increasing speeds until the governor trips, with car speed measured by an independent means.
Question 7: What must be done to an elevator after a governor and safety test is completed successfully?
- Inspect and reset the governor, reset safeties, test normal operation before returning to service (Correct answer)
- Replace all governor rope segments
- Install new safety jaws and retest
- Submit the elevator for re-certification immediately
Correct answer: Inspect and reset the governor, reset safeties, test normal operation before returning to service
After a safety test, the governor must be reset, safety devices inspected and reset, and normal operation verified before the elevator returns to passenger service.
CET Governor & Overspeed Protection 3
What is the purpose of the governor rope tension device (tensioning sheave)?