CET Maintenance, Inspection & Troubleshooting 2 — Questions and Answers
Question 1: During a periodic inspection, an elevator's safeties fail to engage during a drop test. What is the FIRST corrective action?
- Adjust the governor rope tension
- Take the elevator out of service immediately (Correct answer)
- Lubricate the safety jaws
- Increase the counterweight
Correct answer: Take the elevator out of service immediately
A failed safety drop test is a critical failure requiring immediate removal from service until the fault is diagnosed and corrected.
Question 2: A hydraulic elevator exhibits slow leveling at the top floor but normal leveling elsewhere. The MOST likely cause is:
- Contaminated hydraulic fluid
- A worn pump coupling
- Excessive pressure at the top of the cylinder stroke (Correct answer)
- A faulty lowering valve solenoid
Correct answer: Excessive pressure at the top of the cylinder stroke
Near the top of cylinder travel, fluid flow resistance increases, causing sluggish leveling; adjusting the deceleration valve corrects this.
Question 3: What does the term 'car sill gap' refer to in elevator inspection?
- The vertical gap between the car floor and hoistway wall
- The horizontal gap between the car sill and landing sill (Correct answer)
- The clearance above the car top
- The space between guide rail brackets
Correct answer: The horizontal gap between the car sill and landing sill
The car sill gap is the horizontal space between the car sill and the hoistway landing sill, which must not exceed code limits to prevent entrapment.
Question 4: Which test verifies that an elevator cannot be driven beyond the terminal landings under normal operation?
- Slack rope switch test
- Normal terminal stopping device test (Correct answer)
- Final limit switch test
- Buffer engagement test
Correct answer: Normal terminal stopping device test
Normal terminal stopping devices (slowdown switches) must stop the car at or before the terminal landings under normal operating conditions.
Question 5: An elevator repeatedly trips its thermal overload relay. After resetting, the problem recurs within minutes. The BEST next step is to:
- Replace the overload relay with a higher-rated unit
- Check motor current draw and compare to nameplate amperage (Correct answer)
- Bypass the overload temporarily to allow service
- Increase the relay's trip delay time
Correct answer: Check motor current draw and compare to nameplate amperage
Recurring thermal overloads indicate excessive current draw; measuring actual motor amperage versus nameplate rating identifies the root cause.
Question 6: What is the purpose of the 'pit stop switch' on a traction elevator?
- To prevent car movement when personnel are working in the pit (Correct answer)
- To stop the elevator if the pit floods
- To activate the pit lighting circuit
- To cut power to the buffer springs
Correct answer: To prevent car movement when personnel are working in the pit
The pit stop switch interrupts the safety circuit so the car cannot move while a mechanic is working in the pit, protecting against accidental entrapment.
Question 7: During a maintenance inspection, a technician finds that the car gate switch bypasses when the gate is 3 inches open. This is a violation because ASME A17.1 requires the gate to be closed to within:
- 1/2 inch (Correct answer)
- 1 inch
- 2 inches
- 4 inches
Correct answer: 1/2 inch
ASME A17.1 requires hoistway and car doors/gates to be within 1/2 inch of the fully closed position before the interlock circuit can complete.
CET Maintenance, Inspection & Troubleshooting 2
During a periodic inspection, an elevator's safeties fail to engage during a drop test.
What is the FIRST corrective action?