The Keystone F28T5/HE,
F21T5/HE or F14T5/HE electronic ballast from Warehouse-Lighting can accommodate
one, two, three or four lamps. Weighing 2.21 pounds this is a dependable
ballast with a high power factor and a normal ballast factor. It has a minimum
start temperature of 0 degrees Fahrenheit.
This is a program-start
ballast, which means that it’s easier on lamps than instant-start ballasts.
That’s because it preheats the cathodes at low voltage, decreasing cathode
wear. Although program-start ballasts are less energy efficient than instant-start
ballasts, they make sense for situations in which lamps will be frequently
turned on and off, because lamps in program-start fixtures will last longer
under these circumstances.
The manufacturer of
this 120-277V ballast, Keystone Technologies, was founded by a World War II veteran
and has been in business in Pennsylvania for more than 70 years. Known for its
commitment to quality, Keystone covers this ballast with a five-year warranty.