Last fall, TED Magazine published my column on fluorescent emergency ballasts, available here.

A fluorescent emergency ballast is basically a ballast with a built-in battery that senses when power is cut to the unit, resulting in relays inside the ballast switching to battery power to operate the lamp(s) and produce code-compliant illumination during an emergency.

Corridor with all lamps ON. Image courtesy of Bodine.

Corridor with all lamps ON. Image courtesy of Bodine.

The approach has several advantages:

* The emergency lighting is “invisible”
* Because the ballast is concealed, a degree of tamper resistance is acquired
* Can be a fast and economical retrofit solution

Ideal applications:

* When retrofitting fluorescent lighting to be more energy-efficient
* Corridors, intersections, stairwells and other fluorescent lighting
* Large office buildings, schools and colleges, hospitals, nursing homes, prisons, auditoriums, stadiums
* Growth application: Hi-bay spaces where MH fixtures are replaced with fluorescent to save energy

Corridor during power cut with emergency lighting in operation provided by a fluorescent emergency ballast. Image courtesy of Bodine.

Corridor during power cut with emergency lighting in operation provided by a fluorescent emergency ballast. Image courtesy of Bodine.

Characteristics (generally speaking, individual products may vary):

* Operate most single- and bi-pin linear lamps
* Operate most 2- and 4-pin CFLs
* Typically operates a single lamp in a fixture to provide 500-3,000 lumens of light output
* Compatible with most 1, 2-, 3- and 4-lamp electronic, standard, energy-saving and dimmable AC-power ballasts
* Compatible with energy-saving controls such as occupancy sensors and photosensors

Special features:

* Self-diagnostic and self-testing emergency ballasts
* Compatibility with low-mercury CFLs via AC output current
* Compact sizing for installation in small fixtures and spaces
* Parallel operation of two lamps
* Delay circuits to ensure compatibility with new ballast technology
* Suitability for special applications such as outdoor egress and damp locations

And what’s next: Emergency battery packs to drive LED lighting in emergency mode for 90 minutes to meet code.

This, and more, here.