CAT Electrical and Wiring Fundamentals Flashcards
6 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 6 CAT Electrical and Wiring Fundamentals flashcards as text
What voltage level is most commonly used for residential security alarm control panels?
Answer: 12V DC
Most residential alarm panels operate on 12V DC supplied by a plug-in transformer and backed up by a 12V sealed lead-acid battery.
What is a 'home run' wiring method in alarm installations?
Answer: Each device is wired directly back to the panel with its own dedicated wire run
A home run configuration gives each zone or device its own dedicated wire back to the panel, making troubleshooting and zoning simpler.
What causes voltage drop in long alarm wiring runs?
Answer: Wire resistance increases with length, reducing voltage at the device
Longer wire runs have more resistance, which causes a measurable voltage drop that can prevent sensors or keypads from operating correctly.
Which battery chemistry is most commonly used for alarm system standby power backup?
Answer: Sealed lead-acid (SLA)
Sealed lead-acid batteries are the industry standard for alarm backup power due to their reliability, cost, and compatibility with trickle-charging circuits.
What is the function of a tamper switch on an alarm device or enclosure?
Answer: Trigger an alert if the device cover is removed or the enclosure is opened
Tamper switches detect unauthorized physical access to alarm devices or panels and send a tamper signal to the monitoring center.
What is the minimum wire size permitted for power-limited fire alarm circuits under NFPA 70 (NEC)?
Answer: 26 AWG
NEC Article 760 permits power-limited fire alarm (PLFA) circuits to use wire as small as 26 AWG, though 18–22 AWG is typical in practice.