DCI Tools & Equipment Operation 4 — Questions and Answers
Question 1: When using a rotary impact hammer drill to anchor a cable tray bracket into a concrete ceiling, which personal protective equipment (PPE) is mandatory?
- Only safety glasses
- Safety glasses, hard hat, and hearing protection at minimum (Correct answer)
- Only a hard hat
- Gloves and steel-toed boots only
Correct answer: Safety glasses, hard hat, and hearing protection at minimum
Overhead concrete drilling produces falling debris (hard hat), high-velocity chips (safety glasses), and excessive noise levels (hearing protection), making all three mandatory.
Question 2: A fiber optic cleaver is used instead of a scribe-and-break method because it:
- Requires no consumable blades
- Produces a flat, perpendicular end-face required for low-loss fusion splicing or connector termination (Correct answer)
- Is faster for field terminations than scribing
- Automatically polishes the fiber end after cutting
Correct answer: Produces a flat, perpendicular end-face required for low-loss fusion splicing or connector termination
A precision cleaver creates a geometrically flat, mirror-smooth fiber end face, which is essential to minimize insertion loss when splicing or connecting optical fiber.
Question 3: What does an insertion loss test on a fiber link measure?
- The total length of the fiber run
- The total signal power lost between the light source and power meter, expressed in dB (Correct answer)
- The number of splices in the link
- The fiber's core diameter
Correct answer: The total signal power lost between the light source and power meter, expressed in dB
Insertion loss testing injects a known optical power level and measures received power; the difference in dB represents the total link loss from connectors, splices, and fiber attenuation.
Question 4: Why is it important to use the correct blade setting on a termination strip (Krone) punch-down tool?
- An incorrect setting changes the punch-down speed
- The blade must match the IDC manufacturer's specification — incorrect blades can split contacts or fail to fully seat conductors (Correct answer)
- Only one universal blade fits all IDC types
- The setting affects only cut wire length, not contact seating
Correct answer: The blade must match the IDC manufacturer's specification — incorrect blades can split contacts or fail to fully seat conductors
Krone, 110, and BIX IDC contacts have different geometries; using the wrong blade can damage the plastic body or leave conductors partially seated, causing intermittent faults.
Question 5: A cable tray fill calculation indicates the tray is at 40% fill. Under NFPA 70 (NEC), ladder-type cable trays for data cables generally allow a maximum fill of:
- 25% of the tray cross-section
- 50% of the tray cross-section for 4-inch depth trays with single-layer cables (Correct answer)
- 100% — cable trays have no fill limit for data cable
- 75% when cables are bundled
Correct answer: 50% of the tray cross-section for 4-inch depth trays with single-layer cables
NEC Article 392 limits cable tray fill based on tray depth and cable type; for 4-inch ladder trays with multiconductor data cables, single-layer fill up to 50% of the usable interior cross-section is typical.
Question 6: Which tool is used to test a coaxial cable connector's return loss and confirm that F-type or BNC connectors are properly installed?
- Cable toner
- Vector network analyzer or coax sweep tester (Correct answer)
- Optical power meter
- Wire map tester
Correct answer: Vector network analyzer or coax sweep tester
A coax sweep tester or VNA measures return loss across a frequency range, confirming that coaxial connectors are properly crimped and impedance-matched to the cable.
Question 7: When using a manual cable reel stand to pay out cable from a large spool, the spool should rotate so that cable feeds:
- From the bottom of the spool, rolling forward
- From the top of the spool, in the direction opposite the pull to prevent kinking (Correct answer)
- In any direction — spool orientation does not matter
- Clockwise only, regardless of pull direction
Correct answer: From the top of the spool, in the direction opposite the pull to prevent kinking
Cable fed from the top of a properly oriented spool unwinds with the natural lay of the cable, minimizing twist and preventing kinks that could damage pair geometry.
DCI Tools & Equipment Operation 4
When using a rotary impact hammer drill to anchor a cable tray bracket into a concrete ceiling, which personal protective equipment (PPE) is mandatory?