If you own a building with an emergency generator electrical system integrated into its frame, routine automatic transfer switch maintenance is critical to ensure that you can function properly while utilizing the system. Automatic transfer switches monitor the voltage levels of the building's normal power supply and switch to emergency power when these voltage levels fall below a certain preset threshold. If a particularly severe storm or rolling blackout disrupts your main power source, an automatic power transfer switch will seamlessly and efficiently activate your emergency power system. So how do you test the performance of auto transfer switch?