Interior decorators use ballast cross reference charts when substituting fluorescent lighting ballasts with equivalent parts from another manufacturer. These charts provide important information necessary for the safe installation and operation of fluorescent lighting systems.
Fluorescent lighting ballasts perform three critical functions. Proper ballasts supply the correct start-up voltage to each lighting array, quickly reduce the voltage to prevent burnout once the lamps are lit, regulate the current during operation, and compensate for differences between the required voltage and the voltage in the electrical lines. Using incorrect ballast components wastes electricity and can damage the lights. It may also create safety hazards.
Noise production is an important factor in lighting ballast selection. Ballast noise is rated on a scale from A to D. Units rated A produce very little noise, while those rated D generate much more. Electric ballasts typically produce considerable noise during operation. The buzzing sound these ballasts create increases as the units' temperature increases, which means that uninsulated electric ballasts made from cheap materials tend to produce more noise than more expensive models. Another type of ballast is the magnetic ballast. Units in this category generally produce less noise than electric ballasts, which makes them very popular in libraries and other spaces where noise is undesirable.