Purpose of Electronic Ballasts

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

Considerations for Choosing the Right Ballast

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 Comparison

Feature	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