CAT Installation Practices and Wiring

Question 1

What type of cable is typically used for balanced audio connections between equipment in commercial installations?

Accepted Answer

Twisted pair shielded cable

Answer

Coaxial cable

Answer

Flat ribbon cable

Answer

Category 5e unshielded cable

Question 2

What connector is the industry standard for balanced XLR audio connections in commercial audio systems?

Accepted Answer

3-pin XLR

Answer

1/4" TRS

Answer

RCA phono

Answer

BNC

Question 3

According to NEC guidelines, what is the maximum recommended conduit fill ratio when pulling three or more conductors?

Accepted Answer

40%

Answer

25%

Answer

60%

Answer

75%

Question 4

Which wire gauge is most commonly specified for low-impedance loudspeaker runs in commercial audio installations?

Accepted Answer

14 AWG

Answer

22 AWG

Answer

18 AWG

Answer

8 AWG

Question 5

What is the primary purpose of inserting a ground lift on a cable connection in a commercial audio installation?

Accepted Answer

To break a ground loop and eliminate 60 Hz hum

Answer

To increase signal level across the run

Answer

To convert an unbalanced signal to balanced

Answer

To step up the cable impedance

Question 6

What does the term 'home run' describe in the context of commercial audio wiring?

Accepted Answer

Running each device's cable directly back to a central rack or patch bay

Answer

A cable run that loops back to its starting point

Answer

The longest single cable run in a system

Answer

The primary mains audio feed path

Question 7

Which type of conduit is typically required when audio cable runs must penetrate fire-rated wall assemblies in commercial buildings?

Accepted Answer

EMT (Electrical Metallic Tubing) with listed firestop

Answer

Schedule 40 PVC conduit

Answer

ENT (Electrical Non-metallic Tubing)

Answer

Corrugated flexible plastic conduit