What automatically transfers electrical load between two sources?

The device that automatically transfers electrical load between two sources is known as an automatic transfer switch (ATS). An ATS is designed specifically to monitor the primary power source and, in the event of an outage or a significant drop in power quality, it will automatically switch the load over to a backup power source, such as a generator or another utility line, without requiring manual intervention.

This automatic switching capability is crucial for maintaining continuous power supply to critical systems, making the ATS a vital component in facilities where uptime is essential, such as data centers and hospitals. The ATS ensures that there is minimal disruption to power delivery, allowing operations to continue seamlessly in the event of power failure.

Other devices mentioned in the options serve different purposes. A transfer switch (often referred to simply as a switch) may provide manual or basic automated switching capabilities but does not typically do so automatically in response to power conditions. An uninterruptible power supply (UPS) provides immediate battery backup for a short time during a power outage, but it does not switch between sources. An automatic voltage regulator (AVR) is used to maintain a consistent voltage level and doesn’t handle source switching. Therefore, the ATS is specifically designed for the automatic transfer function, making it the correct choice for this