CET Traveling Cables & Wiring Methods 1 — Questions and Answers
Question 1: What is the primary function of a traveling cable in an elevator system?
- To provide emergency braking support to the car
- To carry electrical power and control signals between the fixed hoistway wiring and the moving car (Correct answer)
- To balance the weight of the elevator car during travel
- To transmit hydraulic pressure to the car platform
Correct answer: To carry electrical power and control signals between the fixed hoistway wiring and the moving car
The traveling cable provides the continuous electrical connection between stationary building wiring and the moving elevator car, carrying both power and control signals throughout the travel range.
Question 2: Traveling cables used in elevator installations must be:
- Listed specifically for elevator use and capable of withstanding repeated flexing (Correct answer)
- Standard THHN building wire bundled in flexible metallic conduit
- Solid conductor wire rated at 600V minimum per NEC
- Any UL-listed wire of sufficient gauge for the connected load
Correct answer: Listed specifically for elevator use and capable of withstanding repeated flexing
Elevator traveling cables must be specifically listed for this application due to the unique demands of continuous flexing, torsion, and hoistway environmental conditions that standard wire cannot withstand.
Question 3: The traveling cable loop in the hoistway must be arranged so that when the car is at the lowest landing:
- The loop rests on the pit floor to provide maximum slack for movement
- The loop bottom clears the pit floor and all other obstructions in the pit (Correct answer)
- The loop is kept taut with no excess cable to prevent sway
- The cable attaches directly to the pit floor for additional support
Correct answer: The loop bottom clears the pit floor and all other obstructions in the pit
The cable loop must never contact the pit floor or any other obstruction to prevent abrasion, pinching, and damage that would create electrical hazards and operational failures.
Question 4: How must traveling cables be attached at the car and at the overhead support point?
- With cable ties spaced every 12 inches along the cable run
- With strain relief so that conductors are not subjected to tensile stress at terminations (Correct answer)
- Welded directly to the car sling frame for a permanent connection
- With spring-loaded connectors that allow free movement in all directions
Correct answer: With strain relief so that conductors are not subjected to tensile stress at terminations
Strain relief prevents mechanical tension from being transferred to the electrical connections, protecting conductors and terminals from fatigue failures caused by the cable's weight and motion.
Question 5: Per ASME A17.1, traveling cables must maintain adequate clearance from:
- Only the hoistway walls on both sides of the car
- All hoistway equipment, structural members, and moving components except at designated attachment points (Correct answer)
- Only the counterweight and counterweight guide rails
- Only the car guide rails and buffer springs
Correct answer: All hoistway equipment, structural members, and moving components except at designated attachment points
Traveling cables must be routed to maintain clearance from all equipment and structures in the hoistway to prevent damage from abrasion, pinching, or entanglement during car movement.
Question 6: The traveling cable loop transition point (where the cable changes from hanging down to running upward) should ideally be located:
- At the lowest landing to minimize cable stress during high-speed travel
- Near the midpoint of the car's travel range to minimize cable movement and mechanical stress (Correct answer)
- At the top of the hoistway to reduce the unsupported length of cable
- At the machine room floor level for easy inspection access
Correct answer: Near the midpoint of the car's travel range to minimize cable movement and mechanical stress
Positioning the loop transition near mid-travel minimizes the total range of cable movement and reduces cumulative mechanical stress on conductors over the life of the installation.
Question 7: During inspection of traveling cables, which condition requires immediate removal from service?
- Minor surface discoloration from age and normal oxidation
- Exposed or damaged conductors, severe kinking, or cracked insulation (Correct answer)
- Slight stiffness observed in cold ambient temperature conditions
- Cable length providing 8 inches of excess loop at lowest landing
Correct answer: Exposed or damaged conductors, severe kinking, or cracked insulation
Damaged insulation, exposed conductors, or physical deformation create immediate shock hazards and unreliable electrical connections that must be corrected before the elevator is returned to service.
CET Traveling Cables & Wiring Methods 1
What is the primary function of a traveling cable in an elevator system?