What happens if power is not restored within 90 seconds after an auto fail condition?

If power is not restored within 90 seconds after an automatic fault condition, the appropriate response is that the Automatic Transfer Switch (ATS) transitions to provide load. This operation is crucial in ensuring that critical loads receive power without significant delays, which is essential in many applications, particularly in facilities where continuous operation is vital.

The transition to provide load allows the system to engage backup power sources seamlessly, thus maintaining service continuity. The design of such systems prioritizes quick recovery from outages to minimize disruptions, which is why an ATS plays a critical role in automatically switching the power source.

In contrast, resetting the system automatically, shutting down the generator, or having the Human-Machine Interface (HMI) enter maintenance mode are not standard responses when a fault condition is detected and power is not restored promptly. These actions would not effectively address the need for continuous power supply and would potentially lead to increased downtime and risk, highlighting the importance of the ATS’s functionality in maintaining operational stability.