What is Ballast Factor (BF)

Horace He

Last Updated: August 1, 2023

What is Ballast Factor (BF)

Ballast Factor (Bf) is the quantify the efficiency and light output of a lamp-ballast combination in comparison to a reference ballast. It is expressed as a numerical value typically ranging from 0.70 to 1.2, representing the amount of light a lamp will emit when operated with a specific ballast. The calculation of the ballast factor involves dividing the lumen output of a lamp-ballast combination by the lumen output of the same lamp(s) on a reference ballast. A ballast factor less than 1 indicates that the fluorescent system will produce less light (lumens) compared to the reference ballast, while a factor greater than 1 signifies that it will produce more light.

In addition to its impact on light output, the ballast factor indirectly affects energy consumption. Generally, a lower ballast factor results in reduced wattage consumption by the lighting system. This means that selecting a ballast with a lower ballast factor can lead to energy savings.

To better understand the concept of ballast factor, an analogy can be drawn from the automotive world. Similar to how different engine sizes affect fuel efficiency and power output, a lower ballast factor offers higher energy efficiency but may result in lower light output. Conversely, a higher ballast factor may consume more energy but provide increased performance or higher light output.

Frequently Asked Questions

How Often Do Ballasts Need to Be Replaced

According to the Certified Ballast Manufacturers Association, magnetic ballasts typically have a lifespan of approximately 75,000 hours, which translates to an average of 12 to 15 years under normal usage conditions.

How Do You Use Ballast Factor

The ballast factor is a measurement that indicates the proportion of light emitted by a lamp when it is operating in a particular fixture. It is typically provided in the model specifications and can range from 0.70 to 1.20. To utilize this measurement, you need to multiply the lumens rating of the lamp by the ballast factor of the fixture.

What Is the Ballast Efficacy Factor

The ballast efficacy factor refers to the ratio of the light output to the power input of a fluorescent lamp ballast, which is determined by conducting tests according to the specifications outlined in ANSI standard C82.

What Voltage Should I Get Out of a Ballast

The voltage output of a ballast should typically fall within the range of 300 to 1000 volts, varying according to the specific model of the ballast.

What Size Ballast Is Best

The ideal size for ballasts ranges from 1.9 cm to 5.1 cm gauge. It is not recommended to use stones that are larger than 5.1 cm as the interlocking of stones of this size is superior to larger stones. Therefore, the most optimal ballast consists of stones that vary in size from 1.9 cm to 5 cm.

How Do You Determine the Normal Ballast Resistance

To determine the normal ballast resistance, one can measure the voltage across the ignition coil. If the ballast resistor is functioning properly, it will reduce the voltage level to 7-8V. Conversely, if the ballast is faulty, the voltage level of the ignition coil will be higher. The resistance of the ballast resistor can be checked using an ohmmeter.