CET Escalator & Moving Walk Systems 3 — Questions and Answers
Question 1: What is the function of the comb plate on an escalator?
- Guides the handrail into the newel
- Meshes with step cleats at the landing to prevent foot entrapment (Correct answer)
- Supports the step axle bearings
- Controls step leveling at the upper landing
Correct answer: Meshes with step cleats at the landing to prevent foot entrapment
The comb plate's fingers interlock with step cleats at each landing, bridging the gap and preventing feet or objects from becoming trapped.
Question 2: An escalator's step band must be capable of supporting a minimum load of how many pounds per square foot of step surface?
- 75 lbs/ft²
- 100 lbs/ft² (Correct answer)
- 120 lbs/ft²
- 150 lbs/ft²
Correct answer: 100 lbs/ft²
ASME A17.1 requires escalator steps to support a minimum live load of 100 lbs per square foot to ensure structural adequacy under passenger loads.
Question 3: Which safety switch stops an escalator when the skirt panel is deflected inward by an obstruction?
- Comb impact switch
- Skirt obstruction switch (Correct answer)
- Step level switch
- Handrail entry guard switch
Correct answer: Skirt obstruction switch
Skirt obstruction switches detect when objects or clothing are drawn between the step and skirt panel and immediately stop the escalator.
Question 4: During a comb plate impact, what action must the escalator take?
- Reduce speed by 50%
- Activate an alarm only
- Stop immediately (Correct answer)
- Reverse direction
Correct answer: Stop immediately
A comb impact switch triggers an immediate stop to prevent injury when an object or foot strikes the comb plate with sufficient force.
Question 5: What is the maximum permitted gap between the escalator step riser and the step tread of the following step in the incline section?
- 3/16 inch (Correct answer)
- 1/4 inch
- 3/8 inch
- 1/2 inch
Correct answer: 3/16 inch
ASME A17.1 limits the gap between step components to 3/16 inch (4.76 mm) to prevent entrapment of small feet or footwear.
Question 6: On a pallet-type moving walk, what retains the pallets in their proper lateral position along the track?
- Guide shoes riding on the truss chord
- Pallet axle flanges engaging guide rails (Correct answer)
- The handrail drive belt
- Comb plate teeth
Correct answer: Pallet axle flanges engaging guide rails
Pallet axle flanges or guide wheels engage dedicated guide rails in the truss to keep each pallet laterally aligned throughout the circuit.
Question 7: Under ASME A17.1, an escalator machine room or machinery space must have a minimum headroom clearance of:
- 6 ft 0 in
- 6 ft 6 in (Correct answer)
- 7 ft 0 in
- 7 ft 6 in
Correct answer: 6 ft 6 in
ASME A17.1 requires at least 6 ft 6 in (1981 mm) of clear headroom in escalator machine rooms to allow safe maintenance access.
CET Escalator & Moving Walk Systems 3
What is the function of the comb plate on an escalator?