Editorials

ELECTRONIC BALLASTS

Advantages

Electronic ballasts save energy and money, which is always an advantage. They also improve the quality of light. They operate fluorescent lamps at a much higher frequency than magnetic ballasts, usually in the range of 20 to 50 kilohertz. High frequency operation reduces the flicker effect and reduces the amount of humming noise from the ballast. The flicker effect has been known to cause headaches for some people. Reducing flicker can make a space more visually comfortable.

Disadvantages

Some electronic ballast’s have a relatively high level of total harmonic distortion. Some equipment such as computer systems, retail security tag systems and telephone systems are sensitive to such power quality problems. To combat this problem, ballast manufacturers have made great strides in reducing the total harmonic distortion in their products. Consequently, there are electronic ballasts now available that are rated for less than 10% total harmonic distortion. Ballasts have to conform to a set RFI standard in N.Zealand. This does not however eliminate the occurrence of radio frequency interference in certain circumstances.

Cost

Historically this has always been the big negative with the electronic ballast option. But prices have come down dramatically, and electronic ballasted fittings are currently only 10% to 20% more expensive.

Retrofitting compact fluorescent downlights

Changing existing fittings from magnetic to electronic will no doubt become increasingly popular. There is one complication however, and that is the lampholders have to be changed from 2 pin to 4 pin, and also the lamps will have to be replaced with 4 pin type as well.