What is the wait time to shut off electrical power after EGI?

What is the wait time to shut off electrical power after EGI?

• A. 5 seconds
• B. 10 seconds
• C. 15 seconds
• D. 20 seconds

Answer: (B)

A controlled shutdown sequence is used after EGI to ensure a safe and orderly transition from power. The wait time gives the system a moment to complete the transfer and de-energize in a controlled way, rather than cutting power immediately. Ten seconds is chosen because it provides enough time for relays and interlocks to open, for loads to transfer or discharge as needed, and for voltages and stored energy in capacitors or inductive circuits to settle. This reduces the risk of arcing, equipment stress, or residual energy that could cause harm to maintenance personnel or damage components. If the wait were too short, there could still be partially energized circuits or backfeed conditions during shutdown. If it were too long, unnecessary downtime and potential delays in safe operations could occur. The ten-second interval strikes a balance between safety and efficiency, ensuring a stable, safe power-down after EGI.

A controlled shutdown sequence is used after EGI to ensure a safe and orderly transition from power. The wait time gives the system a moment to complete the transfer and de-energize in a controlled way, rather than cutting power immediately.

Ten seconds is chosen because it provides enough time for relays and interlocks to open, for loads to transfer or discharge as needed, and for voltages and stored energy in capacitors or inductive circuits to settle. This reduces the risk of arcing, equipment stress, or residual energy that could cause harm to maintenance personnel or damage components.

If the wait were too short, there could still be partially energized circuits or backfeed conditions during shutdown. If it were too long, unnecessary downtime and potential delays in safe operations could occur. The ten-second interval strikes a balance between safety and efficiency, ensuring a stable, safe power-down after EGI.