Emergency Lights in Generator Rooms

Q: In regards to emergency generator backup lights, I seek clarity how long does the battery have to last? I’m assuming that the battery should be able to be tested annually for 90 minutes like those inside my hospital.

A: Section 7.9.3 of the 2012 LSC is clear: All required battery powered emergency lights must be tested monthly for 30 seconds and annually for 90 minutes. The NFPA 110 requires a battery powered emergency light in the generator room, so it is a required light that needs monthly and annual testing.

The code requires the light to operate for 90 minutes.