ganjero...Sanjay's tests were performed on the Galaxy, Lumatex and another newer form of electronic ballast whose name escapes me. Apparently, Galaxy and Lumatek have created these new e-ballasts to specifically run Radium and Ushio bulbs.
I realize what you're saying, just can't believe anyone would run these expensive bulbs on such a low par producing ballast.
They fire them up but that doesnt mean they are running to specs like you mentioned on your first post.
Here is something about ballasts and those new e ballast (it's a quote from Paulerik)
"M80 is an ANSI (American National Standards Institute) code specification. Each ANSI specification states the following:
Lamp starting requirements and limits (open circuit voltage, starting current, starting voltage, starting voltage pulse height, pulse width and pulse position).
Lamp warm-up parameters (reignition voltage and sustaining voltage).
Lamp operating parameters (operating current, operating voltage, operating wattage, operating current crest factor, sustaining voltage and voltage rise effect).
Each ANSI code specification varies. Lamp and ballast ANSI codes should always be matched to assure reliable, safe and expected performance. The ANSI code system is designed for matching ballasts and lamps properly.
Magnetic ballasts are designed to limit lamp operating current. An ANSI M80 specification specifies a nominal 3.0 amps to the lamp. The lamp operating voltage is set by the lamp specification/design. The lamp operating voltage can be altered by the lamp's chemistry and discharge chamber (arc tube) size. The lamp operating wattage is set by both the ballast (available current) and lamp (set voltage). With magnetic ballasts it is important to match the ballast specification with the proper lamp. They both work very closely together.
Electronic metal halide ballasts are designed to output a specified wattage and maintain the wattage within a few percent. Generally electronic ballasts are designed to output the lamp's nominal rated wattage and designed to meet the other requirements for the specified lamp.
I personally do not see lamp manufacturers approving the use of some of these electronic ballasts. The switchable electronic ballasts are a nice idea but it still will not allow all lamps to operate as intended or designed. ANSI specifications state the lamp nominal operating wattage. ANSI M58 (probe start 250-watt), ANSI M138/M153 (pulse start 250-watt) and ANSI M80 (pulse start 250-watts) are all specified as 250-watts nominal. However some lamps are designed to a higher operating nominal wattage and some lamps are designed to a lower operating nominal wattage. Note when comparing magnetic ballast's input or even output wattage the ballast circuit type (CWA, CWI, Reactor or High Reactance Autotransformer) has to be taken into account. Each ballast circuit performs differently overtime and has different characteristics. One ballast may draw or provide less power when the lamp is new and increases overtime. Another type can draw or provide more when the lamp is new and actually decreases overtime. Light output initially and overtime will vary with each ballast type as well.
For example the Radium 250-watt lamp is designed to operate at 270-watts nominal when operated with a ballast designed to limit/provide lamp operating current to 3.0 amps same as an ANSI M80 ballast. The Radium 250-watt lamp is designed with a higher lamp operating voltage. When used with the recommended/approved magnetic ballast the lamp is allowed to operate at the designed wattage. The Radium 400-watt lamp is designed to operate at 360-watts when operated with a ballast designed to limit/provide lamp operating current to 3.5 amps. The closest and recommended ballast available in North America is a magnetic ANSI M135/M155 ballast which is designed to limit lamp operating current to 3.25 amps. The Radium 400-watt lamp is designed with a lower lamp operating voltage. When used with the proper magnetic ballast the lamp is allowed to operate at the designed wattage. The magnetic ANSI M80 and ANSI M135/M155 ballasts not only allow the Radium lamps to operate at the designed wattage but also meets all other parameters (starting, warm-up and operating).
Output wattage is only a part of an electronic ballast. An electronic ballast has to be designed to meet the starting, warm-up and operating requirements and limits for a lamp. Most of the electronic ballasts currently available in the hobby do not state which lamps or ANSI specification they are technically designed for or meet. It would be nice to have an electronic ballast that could meet the requirements and limits for all lamp types or ANSI specifications but this is unfortunately impossible. Commercial electronic ballasts from major North American companies such as Advance Philips, Sylvania, Universal and Venture Lighting state which lamps they are designed for and which specifications are met.
Input power and light output tests only show a part of the story. It appears some of these newer electronic ballasts available in this hobby might be pushing the limits. The numbers Sanjay has released do not add up correctly. In my opinion it seems some companies are pushing lamps above the rated lamp wattage to provide higher light output, which makes their ballast appear better than others on paper. Also note generally when you drive a metal halide lamp at higher wattages the efficiency goes up because the lamp's spectrum in broadened. This can also greatly increase the risk of a lamp violently failing. Major lamp manufacturers will not approve the use of a ballast that operates a lamp past the wattage rating because of the increased risk, light color shift and unknown long-term performance. A test showing the output power (lamp operating power) would be nice but it would not be easy unfortunately. The voltages and frequencies these ballasts operate at make it more difficult to get reliable readings and require specialized equipment and testing rigs. Some of the major lamp manufacturers I've personally spoken with haven't been able to test these newer ballasts for approval. It seems as some ballast companies are not wanting to.
If you know which lamp you want to use, it would be best to use the recommended and approved ballast. This assures reliable and safe operation overtime. Not every ballast is the same. With magnetic ballasts you have different circuit types and with electronic ballasts you have different designs but more importantly both magnetic and electronic ballasts should be match with the proper lamp. Each type has its own ups and downs.
Hope that helps some"
