My response to question 3:
Yes, I do own a rare North American specification Jefferson Electric high power factor 400W H33 mercury vapor high power factor HX ballast. It has the part number “233-1331”. Usually, most North American 400W H33 mercury vapor HX ballasts that I have read about are low power factor ballasts due to the absence of a capacitor wired in parallel with the mains. Examples of those ballasts can be found in Westinghouse’s OV400 security light, which has the exact same fixture body as a Westinghouse OV15 street light and a few versions of GE’s 400W PowerBracket security light fixtures.
Usually, lag type ballasts for larger mercury vapor lamps in North America are either 240V 60Hz reactor ballasts for 1000W H34 mercury vapor lamps or 480V 60Hz reactor ballasts for 1000W H36 mercury vapor lamps. On an interesting note, I have also found some evidence that North American mercury vapor HX ballasts were even available in 1000W H36 mercury vapor versions under the following part numbers:
GE 9T65Y2250 (1 lamp) 120V 60Hz tap available
Jefferson 232-1366 (1 lamp) 120V 60Hz tap available
Jefferson 232-2366 (2 lamps) 120V 60Hz tap available
Jefferson 233-1366 (1 lamp) 120V 60Hz tap available
I have found out about them after reading a GE brochure about its “I-Line” metal halide retrofit lamps designed for operation on mercury vapor ballasts. There might be more 1000W H36 mercury vapor HX ballasts out there under different part numbers, but they seem to be extremely rare.
See here:
https://www.lighting-gallery.net/gallery/displayimage.php?album=search&cat=0&pos=3&pid=210282I also read that there might also be evidence of 1000W H34 mercury vapor HX ballasts out there after reading a 1961 Westinghouse mercury vapor lamp brochure had data listed for 120V 60Hz high power factor 1000W H34 mercury vapor HX ballasts:
See here:
https://www.scribd.com/document/394833080/Westinghouse-Mercury-Lamp-Brochure-1961Info is found on page 12. Those ballasts seem to be extremely rare nowadays.
On an interesting note, 100V input mercury vapor HX ballasts for 400W mercury vapor lamps, low voltage 700W mercury vapor lamps (130V 5.9A), and low voltage 1000W mercury vapor lamps (130V 8.3A) are pretty common in Japan and much more common than 100V input mercury vapor CWA ballasts in Japan, plus that country in particular has a very wide plethora of high pressure sodium, quartz metal halide, and even ceramic metal halide retrofit lamps specifically designed as retrofit lamps for use on existing mercury vapor ballasts.
However, all Japanese quartz metal halide and ceramic metal halide retrofit lamps for mercury vapor ballasts that I have seen all seem to only be compatible with HX and reactor ballasts and explicitly warn users to not use them on CWA ballasts.
My partial correction for question 1:
In addition, when I recall looking at some specific information about 2 coil autotransformer HID ballasts, I often see that one coil serves as an autotransformer component to step up or step down the incoming line voltage and the other component serves as a “reactor” or choke component to limit the current. I have read that a transformer that consists of one single coil all by itself is known as an “autotransformer”. However, there were some other members even those with specialized knowledge claim that autotransformer ballasts have no real reactor component.
According to the 1961 Westinghouse, here is the description about how HX ballasts work:
“ THE HIGH REACTANCE BALLAST (Fig. 13) is used with circuits that lack sufficient line voltage to start the mercury lamp directly. This type of ballast consists of an auto-transformer section in series with a reactor element. ln power factor corrected high reactance ballasts, a few extra turns of wire are usually added to the auto-transformer section and a capacitor is then connected in parallel with the auto-transformer. The function of the auto-transformer is to step up the voltage to the value required to start the lamp. The reactor section limits the current as required by specifications.”
You can find this engineering bulletin that talks about this situation here:
https://www.scribd.com/document/394833080/Westinghouse-Mercury-Lamp-Brochure-1961The information is on page 12 of the bulletin.
My response to question 2:
As far as I understand, penning start high pressure sodium retrofit lamps specifically designed for use on mercury vapor ballasts are said to only be compatible with HX and reactor ballasts instead of CWA ballasts because these high pressure sodium lamps and standard high pressure sodium lamps have a saturated sodium arc tube chemistry. The thing about high pressure sodium lamps with this arc tube chemistry is that they exhibit an increasing operating voltage during their lifetimes. This is said to be detrimental to mercury vapor CWA ballasts and the saturated vapor high pressure sodium lamps that operate on them because the constant current nature of these ballasts causes the lamps to draw excessive amounts of power whenever the operating voltage increases. This could potentially overload the lamp and possibly overload the autotransformer component of CWA ballasts. However, with HX ballasts and reactor ballasts, the lamp is able to maintain its power draw as its operating voltage increases because the operating current decreases as the operating voltage increases.
However, North American high pressure sodium CWA ballasts are able to safely function with standard high pressure sodium lamps because those ballasts usually have a much lower OCV compared to mercury vapor CWA ballasts. This ensures that the lamp cycles before its operating voltage increases to an excessive level.
Please note that I may be wrong in some of my responses.