Installation Practices and Wiring Flashcards
7 cards from real CAT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Installation Practices and Wiring flashcards as text
What type of cable is typically used for balanced audio connections between equipment in commercial installations?
Answer: Twisted pair shielded cable
Twisted pair shielded cable provides balanced audio connections that reject common-mode noise, making it ideal for commercial audio installations.
What connector is the industry standard for balanced XLR audio connections in commercial audio systems?
Answer: 3-pin XLR
The 3-pin XLR connector is the professional industry standard for balanced audio connections, with pins for ground, positive, and negative signals.
According to NEC guidelines, what is the maximum recommended conduit fill ratio when pulling three or more conductors?
Answer: 40%
NEC guidelines specify a maximum of 40% conduit fill for three or more conductors to allow for heat dissipation and future cable additions.
Which wire gauge is most commonly specified for low-impedance loudspeaker runs in commercial audio installations?
Answer: 14 AWG
14 AWG wire is commonly specified for commercial loudspeaker runs as it provides adequate current capacity while keeping cable resistance losses acceptably low.
What is the primary purpose of inserting a ground lift on a cable connection in a commercial audio installation?
Answer: To break a ground loop and eliminate 60 Hz hum
A ground lift disconnects the cable shield at one end to break ground loops, which are the most common cause of 60 Hz hum in commercial audio systems.
What does the term 'home run' describe in the context of commercial audio wiring?
Answer: Running each device's cable directly back to a central rack or patch bay
A home run wiring scheme runs individual cables from each device directly back to a central location such as a patch bay or equipment rack, allowing independent control of every device.
Which type of conduit is typically required when audio cable runs must penetrate fire-rated wall assemblies in commercial buildings?
Answer: EMT (Electrical Metallic Tubing) with listed firestop
EMT is typically required for penetrations of fire-rated barriers and must be paired with listed firestop sealant to maintain the barrier's fire rating.