I wonder if HID lamp ignitors designed for HID lamps with 52-55v arc tubes interchangeable with HID lamp ignitors designed for HID lamps with 100-130v arc tubes and 200-265v arc tubes?

They aren't interchangeable. The ignitor have its rated voltage it is designed to work.

They aren't interchangeable. The ignitor have its rated voltage it is designed to work.

In what ways are these ignitors not interchangeable? For example, what happens if an ignitor for 55v HPS lamps is used on a ballast designed for 100-130v HID lamps?

It gets deeper than that

The ignitor's function is :

1. Detect whether the lamp is working

2. Generate high voltage if the lamp is not working

3. Pass through the current for the working lamp



The detection of lamp working is done by measurement of the voltage across the lamp. The ignitor got to stay off at the highest voltages the lamp arc is supposed to get to (including rising voltage of aging HPS lamps), but activate at the minimum Voc (with big margin for reliable working at low line voltage)

In 230V ignitors (rectified line voltage is 320VDC) the line is drawn at about 220VDC. This is suitable for all lamps that run on chokes at 230V, and probably for all lamps that use Voc close to 230V (including lamps on HX ballasts in the US). However, ometimes aging lamps actually do reach to peaks (reignition peaks after zero crossing) around that voltage, which causes some ignitors to start generating high voltage on a working lamp. The interference is then visible in the light output, and with lamps nearing EOL can make the lamp extinguish (before the lamp would get cycling on its own)

In 120V ignitors - Everything that works at 55V arc and 120Voc gotta have lower reaction voltage - Probably around 100..120VDC. An ignitor for 230V will do nothing



The generation of high voltage and the pulse shape and voltage achieved varies between different ignitor types



2 wire ignitors use the voltage kick from the ballast, generated the same as in Fluorescent (without the preheating). This is suitable for assisting lamps that need only a little pulse, like some Probe Start halides. Such ignitors may have limits on the ballast short circuit current they can handle, which goes up more or less with lamp arc current

Ballast dependent ignitors (the ignitors with 3 wires, that connect to a tap on the ballast) discharge a capacitor into a tap on the ballast for making a pulse, and use the ballast to step up the pulse to the high voltages needed for Pulse Start lamps. They require that the tap is positioned correctly for this type of ignitor, to get the correct step up coefficient. They are generally suitable for wide range of lamp wattages, as long as the lamp arc voltage and Voc match, as they dont handle directly the lamp current



Superimposed ignitors also generate high voltage by discharging a capacitor into a tap, but they contain the pulse transformer inside the ignitor itself, separating this task from the ballast. The ballast is then only used for the actual ballasting

Ignitors may have different shape of the high voltage pulse. Some ignitors (like ES-50) generate widely spaced, single high energy pulses. Those work well with HPS but can have unreliable hot restarting of Pulse Start MH. Some ignitors (many superimposed ones) generate blocks of small pulses on each AC halfwave. Those work well with all HID lamps



Superimposed ignitors pass thorugh the lamp current when the lamp works. The current goes through the secondary winding of the pulse transformer inside the ignitor all the time, even when no pulses are generated. The winding must be with thick enough wire to handle this current. So, don't exceed the maximum current rating of superimposed ignitors



Also, many ignitors have capacitors that are subjected to ballast Voc. and some contain more complicated electronics (many ignitors have a microcontroller in them..) that use the voltage across the lamp as a supply voltage. The ignitor is capable of filtering out the high voltage pulse from those circuits so that is not a problem. However, connecting it to a Voc higher than it is meant for, may destroy those components, especially in a "lamp failing to start" condition like a hot restart



Many ignitors are not meant for continuous generation of high voltage on a lamp that fails to start. They can overheat or components overstressed by high voltage can fail. Ignitors that use the ballast as the pulse transformer also subject the ballast insulation to overvoltage. Some ignitors and ballasts can handle this well for years, some others will be damaged even just from running for a few weeks with a cycling lamp

Many "smart" ignitors contain a feature that switches them off after failing to start a lamp in a set time or if the lamp is detected to be cycling

Ballast dependent ignitors... discharge a capacitor into a tap on the ballast for making a pulse, and use the ballast to step up the pulse to the high voltage...

Why doesn't that couple back onto mains as obscene EM noise?

In what ways are these ignitors not interchangeable? For example, what happens if an ignitor for 55v HPS lamps is used on a ballast designed for 100-130v HID lamps?

I once accidently used a 35-150w HPS ignitor on a metal halide ballast and it only worked once. Ignitor died.


Now here is a question for you all. I'm asking it anyway even though I expect the answer to be no. Can you use a metal halide ignitor on 250w or higher HPS systems?

The power line is a low impedance source, so on the large scale, it enforces the voltage to remain 120V (230V) regardless of what the connected devices try to do (their impedance is high, wo they are too "weak" to affect the power line). Besides, in this sense the ballast dependant and superimposed ignitors are not different - In all of them the pulse appears in series with the circuit, it's just whether it appears on the ballast itself or on an additional transformer

On the small scale there is some EMI pushed into the power line (can be heard on a radio and maybe even induced into line audio etc). Having a capacitor across the power input (the PF capacitor) helps as it bypasses the pulse from traveling through the power line. (For this a small capacitor of <1 uF is sufficient, the high size of PF capacitor is needed only for the actual PFC function)



If the ignitor you want to use suits the following checklist, the answer could be yes : I assume both are ballast dependant ignitors

 - Can withstand the Voc of the ballast (i guess the Voc of the 2 ballasts to be not too far off each other anyway)

 - Will stay off at the lamp arc voltage. As long as the HPS's voltage is not higher than that of the max halide the ignitor is meant for, this is satisfied

 - Is wired the same way to the ballast, and the tap location throughout the winding is correct :

In many European ballasts, the tap is positioned so that it divides the winding to 80% and 20% parts of the number of turns. But for different ignitor types, the ballast is connected either with end nearest the tap to the lamp, or reversed and connected with the other end to the lamp - You check on the schematic provided with the ignitor how to use the ballast for this ignitor

You can't do this with an autotransformer ballast, so the ignitor must really be intended for the tap position as is in the ballast. Check out in the schematic on the ballast vs. on the ignitor how the tap is positioned in each. They have to match

As ballast dependant ignitors dont handle the lamp current directly, the possibly higher current draw of the HPS does not affect the ignitor