CPCT Cabling Standards & Installation Practices 4 — Questions and Answers
Question 1: According to TIA-568, what is the maximum number of consolidation points allowed in a horizontal cabling run?
- None
- One (Correct answer)
- Two
- Three
Correct answer: One
TIA-568 permits a maximum of one consolidation point per horizontal cabling run between the telecommunications room and the work area.
Question 2: Which pair color scheme is used for T568A wiring on an RJ-45 connector pin 1?
- Orange/White
- Blue/White
- Green/White (Correct answer)
- Brown/White
Correct answer: Green/White
In T568A wiring, pin 1 uses the Green/White (green with white stripe) wire from pair 3.
Question 3: What is the primary purpose of firestopping in telecommunications cabling installations?
- To improve cable performance ratings
- To seal cable penetrations through fire-rated walls and floors to prevent fire spread (Correct answer)
- To insulate cables from electrical interference
- To secure cables to structural supports
Correct answer: To seal cable penetrations through fire-rated walls and floors to prevent fire spread
Firestopping seals penetrations through fire-rated building assemblies to restore the fire resistance rating and prevent the spread of fire and smoke.
Question 4: A technician measures PSACR-F during a cable test. What does this parameter assess?
- Power Sum Attenuation to Crosstalk Ratio at Far-End (Correct answer)
- Pair Signal Attenuation and Crosstalk Ratio-Frequency
- Primary Signal Adjustment Correction Factor
- Pair Sum Attenuation Coefficient Reference
Correct answer: Power Sum Attenuation to Crosstalk Ratio at Far-End
PSACR-F (Power Sum Attenuation to Crosstalk Ratio at Far-End) measures the combined far-end crosstalk from all pairs relative to attenuation, indicating noise immunity.
Question 5: Which grounding practice is required for metallic cable trays used in telecommunications installations?
- Cable trays must be isolated from the building ground
- Cable trays must be bonded to the telecommunications bonding backbone (Correct answer)
- Cable trays require no grounding if non-conductive covers are used
- Cable trays are only grounded at the electrical panel
Correct answer: Cable trays must be bonded to the telecommunications bonding backbone
Metallic cable trays must be bonded to the telecommunications bonding backbone per ANSI/TIA-607 to ensure proper grounding and personnel safety.
Question 6: What installation issue is most likely when a cable tester shows high return loss on a horizontal link?
- The cable was installed in a plenum space
- Impedance mismatches caused by excessive bends, kinks, or poor terminations (Correct answer)
- The cable exceeds the 90-meter maximum length
- The wrong wire map standard (T568A vs T568B) was used
Correct answer: Impedance mismatches caused by excessive bends, kinks, or poor terminations
High return loss is caused by impedance discontinuities from sharp bends, kinks in the cable, or poor termination quality that disrupts the cable's characteristic impedance.
Question 7: Per TIA-569, what is the minimum recommended width of a cable tray in a telecommunications pathway?
- 75 mm (3 in)
- 150 mm (6 in) (Correct answer)
- 300 mm (12 in)
- 600 mm (24 in)
Correct answer: 150 mm (6 in)
TIA-569 recommends a minimum cable tray width of 150 mm (6 inches) for telecommunications pathways to provide adequate cable capacity.
CPCT Cabling Standards & Installation Practices 4
According to TIA-568, what is the maximum number of consolidation points allowed in a horizontal cabling run?