Arc-flash relays can be utilized to sound an alarm when an arcing fault occurs so the worker who is working on the energized equipment can gather his or her tools and get out of the arc flash boundary before being injured.

• A. True
• B. False
• C. They primarily trip the circuit but may also provide alarms
• D. They are not used for alarm functions

Answer: (B)

Arc-flash protection relays are designed to detect arcing faults and rapidly trip the circuit to interrupt the fault and reduce the energy released in the arc. That quick tripping action is the primary safety function, aimed at protecting workers by stopping the fault before severe injury can occur. Alarms can be included as a secondary feature to alert personnel or control rooms, but they should not be relied upon to protect a worker or to evacuate them from the arc-flash boundary. In real scenarios, the arc can cause harm in a very short time, and waiting for an alarm is not a reliable protection strategy. Therefore, the statement is not correct.