e-ARC Keeper detects the interruption before it can become problematic to the lamp and immediately begins supplying supplemental power to the electronic HID ballast. It supports the ballast for 30 seconds, enough time for a power disturbance to pass or a generator to engage. e-ARC Keeper, like other ARC Keeper models, eliminates nuisance downtime and restrike periods caused by short duration power disturbances. Also like other ARC Keeper models, e-ARC Keeper allows an HID fixture to serve as an emergency lighting unit. It does so by supporting the HID ballast during the transition to and from generator power. Such transitions without e-ARC Keeper support would extinguish the lamp arc. The Philips Bodine e-ARC Keeper is ideal for retail, office and other environments utilizing low-wattage HID metal halide lighting. It offers versatile mounting options and can be installed on the fixture or up to 250 feet from the fixture.