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.
- Length: 18.55"
- Width: 1.31"
- Height: 1.03"
- Mounting: 17.53"
- Weight: ;2.21 ;lbs