Manual: Laboratory
Chapter: Environment of Care EC
Topic: Automatic Transfer Switch (ATS) transfer time requirements - Testing

What is the requirement for testing essential electrical system transfer switches (automatic and manual)?

Any examples are for illustrative purposes only.

The Joint Commission standard EC.02.05.07 EP7 requires that all automatic transfer switches are tested monthly. Testing activities are to be conducted in accordance with the manufacturer's instructions for use.  There must be documentation of the result. 

The monthly generator load test must include a complete simulated cold start along with automatic and manual transfer of all essential electrical system loads. It is best practice, but not a requirement, to initiate the load test with a different ATS each month.  

The weekly inspection of the emergency power supply system (EPSS) as per EC.02.05.07 EP 4 requires that all associated components and batteries be inspected which include all ATS, battery chargers, radiator, fuel pumps, etc. 

Each ATS is uniquely identified in the equipment inventory so that testing for each unique piece of equipment or device is tested to demonstrate that the testing and inspections have been completed as required. 

The essential electrical system must be maintained to supply emergency power within 10 seconds of loss of normal power. If the 10-second criteria is not met during regular testing, the organization must have a process to confirm on an annual basis that the 10-second criteria can be met. 

Reference: 
NFPA 99-2012, 6.4.4.1.1 
Last updated on May 09, 2023 with update notes of: Review only, FAQ is current
First Published Date: April 11, 2016
Last Reviewed Date: October 25, 2021