The operational and energy efficiency of lamps and their longevity depend to a large extent on the type of ballast that has been fitted to the light. The ballast is an electrical component that controls the amount of electric current flowing through the lamp, when the latter is switched on and while it is running.
The ballast provides adequate voltage to establish an arc between the two electrodes to switch on the lamp. It then reduces and regulates the voltage to a steady amount as the electrodes are heated to keep the lamp powered on and make it emit light at a consistent level of brightness. When a lamp is hooked directly to a source of electrical power without a ballast to regulate the flow, there is always the risk of the lamp becoming overheated and burning out.
Must be Compatible
There are many different types of ballast. Each type is suited to the specific operational patterns of various different lamps. For instance, some ballasts are not suitable for lamps that are switched on and off frequently. When the ballast and the lamp are not compatible, you can end up reducing the operational efficiency and longevity of the lamp.
Frequent lamp replacement eats into your savings, and you cannot optimize the returns on your infrastructural investment. That is why, business owners should know about the principal types of lamp ballasts—instant and programmed start ballasts—to ensure that they make the right choice for the lamps at their commercial premises.
What are Instant Start Ballasts?
Instant start ballasts are ideal for use with fluorescent lamps that are not switched on and off frequently. Such a type of ballast provides a high amount of voltage to the lamp when it is switched on, but without pre-heating the cathodes either during the start or while the lamp is lighted.
The ballast provides this high mount of voltage to all parts of the lamp, and this usually has the lamp emitting light within about 50 milliseconds. Instant start ballasts do not heat the cathodes of the lamp, so emissive material is released to keep the lamp powered and emitting light.
The greatest advantage of the instant start ballast is that it consumes far less amount of energy than any other type of lamp ballast. In fact, it is considered to be the most energy-efficient ballast solution for most types of fluorescent lamps. This ballast is commonly used by business owners in spaces like restrooms, reception areas, and retail exhibition areas where the lights are not frequently switched on and off. However, this ballast reduces the life span of lamps if fitted on lighting devices that have frequent on/off cycles.
What are Programmed Start Ballasts?
The programmed start ballast is markedly different from the instant start ballast in that the former applies heat to the cathodes of a lamp to switch it on. Also unlike the instant start ballast, the programmed start ballast triggers a specific sequence of events to ultimately power on the light. The steps initiated by the programmed start ballast are listed below.
1. Application of Low-Degree of Heat to the Cathodes or Pre-Heating of the Cathodes
The programmed start ballast reduces the amount of voltage across the lamp before supplying voltage to pre-heat the cathodes. The ballast is programmed to continue supplying voltage till the cathodes reach a temperature of at least 700-degree Celsius. The time until the cathodes are being pre-heated is called the preheat interval.
The voltage across the lamp is kept low during the preheat interval to reduce the amount of glow current. Glow current is the actual electrical current that flows across the cathodes. The more the amount of glow current flowing across the body of the lamp, the more is the blackening of the lamp body. What is more, a large amount of glow current passing between the cathodes results in greater loss of the emissive material. These two developments reduce lamp life significantly. So by doing away with these occurrences, programmed start ballasts prolong the life span of lamps with frequent on/off cycles.
After the above-mentioned first step is complete, the programmed start ballast automatically proceeds to the second step, which is applying voltage across the lamp to establish an arc. The completion of this step results in the lamp emitting light. There is minimal loss of emissive material while voltage is being applied throughout the lamp, and this prolongs the life span of the lighting device.
2. Application of Voltage Across the Lamp
Most sophisticated programmed start ballasts move on from pre-heating the cathodes to supplying voltage across the lamp within 30 milliseconds. This fast transition time minimizes the loss of cathode emissive material that, in turn, increases the life span and improves the operational efficiency of the lamp. Although the instant start ballasts are more energy-efficient, some varieties of programmed start ballasts can reduce the amount of voltage supplied to the cathode to save more electricity. However, the most prolific advantage of programmed start ballasts is that they can facilitate 40,000 starts without degrading the lamp quality.
The above-mentioned differences between instant and programmed start ballasts will help you analyze the lighting operational conditions at your workplace and buy ballasts accordingly.
