The ISD-80 Self-Diagnostic Fluorescent Emergency Ballast allows the same fixture to be used for both normal and emergency operation. In the event of a power failure, the ISD-80 switches to the emergency mode and operates one of the existing lamps for 90 minutes. The unit contains a battery, charger, and inverter circuit in a single can and can be mounted in the wireway or on top of the fixture. The ISD-80 can be used with most 2-4 T8 thru T12 and 2-4 14W-54W T5 fluorescent lamps, with an initial output of up to 1100 lumens for one lamp, and features lamp selector leads for optimizing light output for designated lamp types. The ISD-80 will self-test for thirty seconds monthly and for ninety minutes annually and will diagnose potential problems within the light fixture. If problems are encountered, the unit will specify failure of the battery, charge, lamp, or inverter by means of a flashing red indicator. The dual color LED indicator is lit red when charging and lit green when ready. The ISD-80 utilizes AC output to ensure compatibility with new lamp technologies and is suitable for use in damp locations and in enclosed and gasketed fixtures.