Automatic Transfer Switch (ATS)
What it means.
An automatic transfer switch, or ATS, is the device that detects a utility power failure, disconnects a facility from utility power, and connects it to a standby generator, then reverses the process once utility power is stable. It is the component that actually delivers backup power to the building, not the generator engine itself.
Governing standard
ATS performance and testing requirements are addressed under NFPA 110 (Standard for Emergency and Standby Power Systems), which requires each transfer switch to be operated monthly, and the switch itself is typically listed to UL 1008.
Related service
Hedgehog Power Systems handles this under Control Panel & ATS Modernization.
Also in the glossary.
NFPA 110 Level 1 and Level 2
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Emergency Power Supply System (EPSS)
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Wet Stacking
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Breaker Trip Time Testing
Breaker trip time testing measures how quickly a circuit breaker opens under a simulated overload or fault, co...
Power that stays on.
Preventive maintenance, testing, and repair for standby generators across Illinois and the Midwest. One call reaches a technician, not a call center.