Prior to the late 1970's, ballast manufacturers used a group of compounds called polychlorinated biphenyls, or PCBs, to insulate and cool the inner components in certain electrical products. One common application was to cool the internal capacitor of fluorescent lamp ballasts. These components contained a small amount of PCB oil and most of it is typically absorbed by several layers of paper within the device. Since these compounds were found to be health hazards and were linked to the development of certain cancers, they were prohibited by the US Congress in 1979. The … Continue reading

T5 and T5HO fluorescent high bay fixtures and other T5-based specialty lights are built around a linear fluorescent tube lamp.  Like other types of lamps, the number in the name of the lamp reflects its size.  The “T5” name reflects the diameter of the tube in eighths of an inch.  A T5 lamp is five-eighths of an inch (5/8”).  Similarly, a T8 fluorescent lamp is eight-eighths (or one inch) in diameter and a T12 fluorescent lamp is 12 eighths (or 1-1/2 inches) in diameter.  One of the features that make a T5 bulb and T5-based high bay light fixtures more efficient is the f … Continue reading