What is the use of relay in ups?

A relay in an Uninterruptible Power Supply (UPS) serves as an automatic switch that controls the flow of electrical power between the UPS and the connected load. It ensures that power is seamlessly transferred from the utility supply to the battery backup when a power failure occurs, and vice versa when normal power is restored. This rapid switching helps maintain a continuous power supply to critical devices, preventing interruptions and potential data loss. Additionally, relays can help manage different operational modes of the UPS, such as charging and inverter modes.