CAT CAT Electrical and Wiring Fundamentals

Question 1

What wire gauge is most commonly used for low-voltage alarm system wiring?

Accepted Answer

22 AWG

Answer

22 AWG is the standard low-voltage wire gauge used in most residential and commercial alarm system installations.

Question 2

What is the purpose of an end-of-line (EOL) resistor in a security alarm circuit?

Accepted Answer

Supervise the circuit so the panel can detect a cut or shorted wire

Answer

An EOL resistor allows the panel to continuously monitor the circuit integrity and distinguish between a fault, tamper, or alarm condition.

Question 3

Which type of wiring configuration is required by NFPA 72 for Class A fire alarm circuits?

Accepted Answer

Loop/return path so the circuit survives a single open fault

Answer

Class A wiring provides a redundant return path so the system continues to operate even when one section of wire is broken.

Question 4

What does a supervised circuit in a security alarm system detect?

Accepted Answer

Wire cuts and short circuits

Answer

A supervised circuit continuously monitors wiring integrity and alerts the panel if the wire is cut (open) or shorted.

Question 5

Why is shielded cable recommended for alarm keypad wiring?

Accepted Answer

To reduce electromagnetic interference that could cause false signals

Answer

Shielded cable blocks EMI from nearby electrical sources, preventing corrupted data signals on sensitive alarm communication lines.

(CAT) Certified Alarm Technician Practice Test