Ballasts start lamps and provide the proper voltage to establish an arc between the lamp's two electrodes. There are two types of starting methods.
Instant Start: the least expensive method, starting lamps without delay (< 0.1 seconds) or flicker
- Best suited for applications with limited switches (the number of on/off cycles ) each day
- Ballasts provide a starting voltage sufficiently high enough to start a discharge through the lamps without the need for heating lamp electrodes
- Elimination of electrode heating maximizes energy savings – typically saving 2 watts per lamp compared to rapid start ballasts
- Lamps operated by instant start ballasts typically operate 10,000 to 15,000 switch cycles before failure
Program Rapid Start: allows more starts per lamp, therefore maximizing lamp life
- Designed to provide maximum lamp life in frequent lamp starting applications such as areas where occupancy sensor controls are used
- Start lamps quickly (1.0 – 1.5 seconds) without flicker
- Lamps operated by programmed start ballasts typically operate 50,000 switch cycles before failure
Determining Light Output
- Ballasts regulate the electric current flowing through the lamp to stabilize light output
- Ballast Factor (BF) is a measurement of light output
- Multiplying the BF times the rated lamp lumens will determine actual light output of a given system operated on commercial ballasts.
Rated lamp lumens x Ballast Factor (BF) = Light
Ballast Factors Low: .71 to .78 BF Normal: ∼.88 BF High: 1.15 – 1.25 BF
- A lower than normal BF can save energy but reduces lamplight output to below normal
- A higher than normal BF is used when maximum light from the lamp being used is desired
Determining Lamp Energy Usage
- The amount of energy the lamp is going to use changes depending on the type of ballast being used
- System wattage is determined by lamp and ballast combo
Feature ComparisonFeature | Standard Elect | Centium | Optanium |
---|
Voltage | 120 or 277 | 120/277 Intellivolt | 120/277 Intellivolt |
Efficiency | Better | Good | Best |
Safety Type CC Rating | No | No | Yes |
Cold Start | 0° | 0° | -20° |
Anti-Striation* | No | No | Yes |
*Striation is the spiraling or swirling of fluorescent lamps at initial turn on