Copper Installation Flashcards

What does a 'split pair' wiring error show on a cable tester wire map?

Answer: Correct wire map but failed NEXT test

A split pair shows a correct wire map continuity but catastrophically fails NEXT because the pair twist is broken by mixing conductors from different pairs.

When using a 110-type punchdown block, what type of punchdown tool blade is required?

Answer: 110-type blade

A 110-type blade is specifically designed for 110 connecting blocks and cuts the conductor flush while seating it into the IDC contact.

What is the recommended maximum gap between cable support fasteners (J-hooks or staples) on a horizontal cable run?

Answer: Every 4 to 5 feet

BICSI and TIA guidelines recommend supporting horizontal cable every 4 to 5 feet (1.2–1.5 meters) to prevent sagging and cable damage.

What is 'DC loop resistance' in a copper cable?

Answer: The total resistance of both conductors in a pair measured as a loop

DC loop resistance is measured by connecting the two conductors of a pair at one end and measuring the total resistance of the complete loop at the other end.

Which standard defines the telecommunications pathways and spaces for commercial buildings?

Answer: ANSI/TIA-569

ANSI/TIA-569 (Commercial Building Standard for Telecommunications Pathways and Spaces) covers conduits, cable trays, and equipment room design.

What is the purpose of the blue cable on a T568B-wired horizontal run?

Answer: It is part of pair 1 designated for voice or PoE

In T568B, the Blue/White-Blue pair is pair 1 (pins 4 and 5) and is traditionally used for analog voice or the spare pair in 10/100BASE-T.

A cable is labeled '23 AWG, UTP, Cat6, CMR.' What does 'CMR' indicate?

Answer: Communications Multipurpose Riser — rated for vertical runs in riser shafts

CMR (Communications Multipurpose Riser) is an NEC cable jacket rating suitable for use in vertical riser shafts between floors of a building.