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captdan
02/13/2006, 08:55 PM
can a metal halide ballast degrade or do they just go bad. In other words can they perform less than when new or they either run or not . I borrowed a lux meter and was doing some testing and would appreciate any input.

captdan
02/14/2006, 07:28 PM
bump

cuong
02/15/2006, 10:21 AM
metal halide ballast will either run or not. It will not degrade.

Entropy
02/15/2006, 11:49 AM
Depends on the type of ballast. A magnetic ballast is bullet proof IMO, but the capacitor can go bad. E ballasts are all or nothing in most cases.

captdan
02/15/2006, 07:09 PM
anyone else have a comment. by the way it is a magnetic pfo that is in question. it is around 5-6 years old

PaulErik
02/15/2006, 09:51 PM
The parts that wear out depend on the ballast.

If it is a magnetic ballast the capacitor can fail or operate out of spec overtime. The main component is the ballast coil/s these usually just fail but don’t really wear out.

Some magnetic ballasts have more parts and are configured differently.

If the ballast is a High Reactance Transformer – HX type (all PFO 250-watt HQI / some PFO-watt 150-watt HQI / all PFO 250-watt EYE ballasts) the capacitor is only used for power factor correction.

If the capacitor fails or operates out of spec it just causes the ballast to draw more current/amperage because the power factor lowers. This does not mean it will use more wattage. With a totally failed or removed capacitor the power factor falls to 60-50%.

If the ballast is a Constant Wattage Autotransformer – CWA type (all standard and pulse start PFO ballasts / some PFO 150-watt HQI ballasts / all PFO 400-watt EYE ballasts) the capacitor is used for power factor correction and for lamp power regulation.

If the capacitor operates out of spec the lamp will operate out of spec (usually underdrives the lamp) and generally will not light a lamp reliably. If the capacitor fails or is removed the ballast should not be able to light the lamp.

If the ballast is a pulse start or HQI it is equipped with an ignitor. These usually just fail and last 10,000 hours or more. The ignitor is only used for a few seconds to light the lamp. Once the arc is stable the ignitor turns off.

The main component in some magnetic ballasts that can cause a performance problem is the capacitor.

Hope that helps