Installation Techniques 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 Techniques flashcards as text
When installing a PIR motion detector near an HVAC vent, what problem may result if the detector is aimed directly at the vent?
Answer: The changing air temperature from the vent may cause false alarms
PIR detectors sense changes in infrared radiation; HVAC vents create rapid temperature fluctuations that can be misinterpreted as a person moving through the detection zone.
What is the standard color-coding convention for the positive (+) conductor in a typical 22 AWG, 4-conductor alarm cable?
Answer: Red
Industry convention assigns red to the positive (+) power conductor in alarm system wiring, though local documentation always takes precedence.
A passive infrared detector is rated for 'pet immunity up to 50 lbs.' What does this specification mean during installation?
Answer: Small animals below the weight threshold stay below the detection zone when the unit is mounted correctly at the specified height
Pet-immune PIRs use a lowered sensitivity zone near the floor; when mounted at the correct height, animals below the threshold remain below the active detection curtain.
When running low-voltage alarm wire parallel to 120 VAC electrical wiring inside a wall, what minimum separation is required per NEC guidelines?
Answer: At least 2 inches of separation or a physical barrier between them
NEC Article 725 requires a minimum physical separation or barrier between power-limited (Class 2/3) low-voltage wiring and line-voltage conductors to prevent induction and insulation damage.
A magnetic door contact is installed, but the panel shows the zone as open even when the door is closed. What is the most likely cause?
Answer: The magnet and switch are too far apart or misaligned
Magnetic contacts require the magnet to be within the specified gap distance (typically 3/8 inch or less) to close the reed switch inside the contact body.
What tool is specifically used to punch down alarm wiring onto a 66-block or 110-block terminal strip?
Answer: Punchdown tool (impact tool)
A punchdown (impact) tool seats the conductor into the IDC (insulation displacement connector) terminal and cuts off the excess wire in one motion.
When installing a control panel in a commercial building, what is the primary reason the panel enclosure must be grounded?
Answer: To provide a safe fault current path and reduce electrical noise
Grounding the metal enclosure provides a low-impedance fault current path that causes overcurrent protection to trip and protects personnel from shock.