Which component alerts the operator to a loss of power in the system?

Which component alerts the operator to a loss of power in the system?

• A. PIR
• B. BMS
• C. SMPS
• D. Tamper Junction Box

Answer: (C)

The essential idea here is how power loss is detected and signaled to the operator. The switched-mode power supply includes built-in power supervision: it constantly monitors its input power and, if AC input is lost or drops out of tolerance, it generates a fault indication to the control/monitoring unit. That signal triggers the operator alert so you know the system isn’t powered. The other components don’t provide a direct power-loss alert: a PIR only detects motion, a BMS focuses on battery health/status, and a Tamper Junction Box monitors tamper events. So the device with the inherent power-loss signaling is the power supply.

The essential idea here is how power loss is detected and signaled to the operator. The switched-mode power supply includes built-in power supervision: it constantly monitors its input power and, if AC input is lost or drops out of tolerance, it generates a fault indication to the control/monitoring unit. That signal triggers the operator alert so you know the system isn’t powered. The other components don’t provide a direct power-loss alert: a PIR only detects motion, a BMS focuses on battery health/status, and a Tamper Junction Box monitors tamper events. So the device with the inherent power-loss signaling is the power supply.