How HID BULBS/LAMPS AND BALLASTS Work- Metal Halide, High Pressure Sodium, & Mercury Vapor

How HID BULBS/LAMPS AND BALLASTS Work- Metal Halide, High Pressure Sodium, & Mercury Vapor

A lot of apprentices (and journeymen) have trouble understanding what makes HID lighting any different than regular lighting so troubleshooting them can be a bit confusing. Let’s talk about it!



Instagram –
Discord –
Facebook Page –
Facebook Group –
TikTok –

HID lamps are easy to understand once you wrap your head around the idea that the light inside of one is produced from an arc inside of a tube. There are no metal wires inside of an HID lamp like you’d find in a standard incandescent. In fact this is the philosophy behind fluorescent tubes, neon signs, and compact-fluorescent as well. It’s just an arc being struck in a tube, then the arc mixes with certain chemicals to form an arc-stream to produce visible light.

All HID lamps have a few things in common. 1) They use an arc to illuminate rather than a piece of metal. 2) They all use ballasts. 3) They are all used in relatively the same places – sports arenas/stadiums, street lighting, and parking lot lighting.

How these bulbs differ is where things get interesting:

Metal Halide
Metal Halide lamps use halide salts on the inside of the arc tube. Halide salts such as fluoride, bromide, chloride, and iodide are deposited around the inside of the inner arc-tube and when an arc is stricken through the tube, the halide salts start to vaporize into the arc stream. Each halide salt has a certain color profile that it adds to the finished light output, and a specific temperature has to be maintained in order to keep the lamp at the same color consistency. This is achieved by painting the pinched edges of the arc-tube white to reflect light back into the chamber.

Mercury Vapor
Rather than having any secondary elements in the arc tube to control the light color, a mercury vapor relies solely on the blue light emitted from vaporized mercury (which all 3 of these lamps have). What makes mercury vapor the most recognizable is the white coating around the inside of the lamp’s outer envelope. Much like a fluorescent lamp, a mercury vapor lamp utilizes phosphorescence to control the color. Phosphor glows when introduced to UV light, so this coating helps to make the color of the glowing mercury less blue, and more white.

High-Pressure Sodium
HPS lamps are pretty well known for their yellowish/orange color output. This lamp operates similarly to the MH and MV lamps, however, the substances it uses to achieve its color and efficiency are hotter and require more pressure to ignite. Mercury is still inside of the inner arc-tube, however, there is also sodium which is a very hot burning substance. The arc-tubes of HPS lamps are very skinny and made from an opaque ceramic rather than quartz or glass like a MH or MV lamp would be.


#HIDlights #highintensitydischarge #howHIDworks

Subscribe –



  1. M00nshadow 91 on February 8, 2023 at 11:03 pm

    Ive always loved the light of the Mercury Vapor lamps. Great video

  2. Quinten Clark on February 8, 2023 at 11:06 pm

    MURCURY 9:23

  3. jeffrey wolf on February 8, 2023 at 11:07 pm

    Also ceramic metal halide Bulbs are some of the best running lights I’ve ever seen

  4. Cisar Vialpando on February 8, 2023 at 11:08 pm


  5. Jason Clouthier on February 8, 2023 at 11:10 pm

    Wondering if you could hekp me put my mh1000watts together its a m47 n36

  6. Veso266 on February 8, 2023 at 11:12 pm

    Where can I buy theese, I would realy like to have the white one, because I like when its different color at start

    But are theese made for home use?

  7. jeffrey wolf on February 8, 2023 at 11:14 pm

    As a cannabis grower I start with the metal halide 6,500 Kelvin and then the last two weeks of growing flowering I should say I switch back from high pressure sodium 2,100 Kelvin to 10,000 Kelvin metal halide it attacks the plants and makes them make more trichomes. You’re welcome

  8. James Bowie on February 8, 2023 at 11:14 pm

    The ballast is a highly inductive component. The capacitor is there to adjust the power factor towards 1.

  9. gui Luka on February 8, 2023 at 11:14 pm

    Hello. For depending on the bulbs with metal iodides, high-pressure sodium vapors and mercury vapors? Are their internal sources warmer than halogen bulbs? Sodium vapors or metal iodides, more than mercury vapors?

  10. John H on February 8, 2023 at 11:14 pm

    I hooked up my metal hilight in my tent it turns on for 2sec and turns back off all bran new y u think not working

  11. Pavel Peřina on February 8, 2023 at 11:15 pm

    About low/high pressure sodium I expected they are both orange, but one of them with some pink tint and they start differently. I think mercury lamps are not used since late 80s or so or are they?

  12. 2 TIMOTHY 4:7 on February 8, 2023 at 11:23 pm

    Excellent and detailed explanation. I’ve learned something new. Thank you and God Bless you. Steven.

  13. Corpse1984 on February 8, 2023 at 11:23 pm

    Great video, how about a video on wiring/troubleshooting them?

  14. abby ghani on February 8, 2023 at 11:24 pm

    i have a light pole that has hid light ignites but won’t light up completely, is it the ballast or the condenser

  15. Dan nye on February 8, 2023 at 11:24 pm

    Can someone explain the ballast for the mercury vapor bulbs. Its a single transformer that starts at a higher voltage but once the bulb warms up the voltage changes and it is said that it regulates the current. How is this possible with a single transformer?

  16. greg cook on February 8, 2023 at 11:24 pm

    You don’t mention cannabis at all when talking about HID bulbs!?

  17. Marc Wolfe on February 8, 2023 at 11:24 pm

    I’m doing a lot of research just to make a bat signal halloween decoration from an old tennis court light. Originally ran on 380-480V and I’m trying to figure out how to power off of 110 or 220V.

  18. Josh Benton on February 8, 2023 at 11:28 pm

    Cool video about the "HID" lamps. Two things though, (1) the ballast provides the necessary starting voltage for the lamp and limits the current. The ballast does not spike any voltage to the lamp, (pulse start metal halide & high pressure sodium vapor lamps only). The igniter / starter does the "pulsing" to get the lamp going. Mercury vapor lamps and most metal halide lamps are "probe start" , they have a "third electrode" with a resistor in series with the main electrode. (The igniter is just a capacitor case full of "leading peak" capacitors that builds up an electrical charge, greater than 2KVs to reach "electrical breakdown" in the ark stream. Some lamps can operate on "choke" ballasts, while some may need autotransformer ballasts (CWA or HX). (2) The capacitor is for power factor correction for the ballast creating a "lag" in the circuit. The capacitor reduces this lag and increases the power factor of the circuit. Without the capacitor, the power factor would be considerably low ( about .55 or .65 if your lucky). Adding the capacitor to the circuit raises the power factor to about .90 or even .95. And last but not least, be GENTLE handling these HID bulbs, they’re vacuum jacket bulbs and can explode if enough force is exerted on the bulb glass.

  19. Rasheed Grant on February 8, 2023 at 11:29 pm

    I’ve swapped out a few metal halides for a client and there was a loud coming from a couple of the posts that I didn’t work on. What’s is the cause of that loud hum? It had the igniter setup and the lights still came on and worked fine.
    Very interesting and helpful info here and a troubleshooting video on these lighting systems would be much appreciated.
    Thank you!

  20. MCTech05 on February 8, 2023 at 11:30 pm

    Youtube is sooooo full of shit with these BS ads about their political agenda they truly SUCK!!!!!

  21. Victor V on February 8, 2023 at 11:30 pm

    my hps bulb will not light up. bought a new one and it will not light up. I put in a regular light bulb and it lit up. Is it safe to leave the regular light bulb in it?

  22. MrNater1978 on February 8, 2023 at 11:30 pm

    Would u possibly be able to help me with wiring one of those mercury halide lamps up?

  23. Mr. C on February 8, 2023 at 11:33 pm

    Bitchen vid Dustin

  24. ACvoltage Electrics on February 8, 2023 at 11:34 pm

    Great explanation!

  25. Shah Zaman veloge on February 8, 2023 at 11:36 pm

    Brother show me metal hailid how to connect whit balast and egnetor and capacitor 1000w teubler lamp

  26. Tourista on February 8, 2023 at 11:36 pm

    I know this is an older video but it was awesome and informative. I have an old 200 watt HMI (hydrargum medium arc iodide) studio light and it is basically a fancy compact metal halide lamp “daylight” color fixture. The fixture will not arc and doesn’t make the traditional “Zzzh” sound like it should since it has to have an ignitor. The ballast is electronic and dimmable and uses long cable for wiring. My question is: how can I troubleshoot this light? I have narrowed it down to it NOT being the ballast causing the issue. In the fixture onboard I think it’s just an ignitor and ignitor timer that I have researched on. I haven’t dissected the fixture yet. Also, as a nice useless trivia fact, in studio lights they call the lamps globes. I have no idea why. Anyway I replaced the globe with a new one and it still doesn’t work. Any ideas would be great!

  27. Galligar Camelot on February 8, 2023 at 11:37 pm

    Cool video. .How and where are the capacitors wired with the light and the ballast ?

  28. Black Powder and Lights on February 8, 2023 at 11:39 pm

    they really went backwords in the 70-80s with HPS lights.. the orange light is terrible when driving at night, you cant see parked/broken down cars very well, you cant see pedestrians walking across the streets.. the orange glow hides dark objects too well.. and shadows everything.. they may have alot more lumens per watt than the mercury vapor they replaced.. but mercury vapor lights have better visibility due to having nearly all the color spectrum we can see.. This white light, is why everything is being replaced with LED.. now we have white lights that save energy. despite HPS still having more lumen per watt than even leds… Lumens lux par mean nothing if you CANT see it. This is why im lighting my property with 4 MV lamps.. sure 700 watts is alot of power.. about 20$ a month in energy for me… But the cost even with cheap 70w dusk to dawn LEDs isnt worth it.. itd cost me $500 to get 4 new leds.. and itd take 4 years to see me save money on power for that $500 cost… then another 4 years to even save $500 in power.. Will those chinese led fixtures last 4 years or 8 years or even 12 months ? i doubt it.. Which is why im sticking with my mercury vapor lamps.

    The only thing LED i switched too are from incandescent interior lights, or halogen flood lights

  29. MetalPete the metalfan on February 8, 2023 at 11:39 pm

    Very useful video since I had a fascination with these as a kid but had no resources to learn about this or anyone to ask that could explain like this. I mostly was interested in seeing the startup of these lights. Every gym I went to school at had the metal halides and many indoor pools I went swimming at as a kid also had these. My middle school pool had incandescent cylinder fixtures with self ballasted mercury vapor bulbs in them which they looked like incandescent when started up then faded to mercury vapor color.

  30. Ryan Journeyman Wireman on February 8, 2023 at 11:40 pm

    I must admit Electrician U isn’t exactly my style … but this was by far one of the best electrical videos I have seen for some time…

  31. noneyabusiness on February 8, 2023 at 11:42 pm

    Great Rundown!

  32. mrneako on February 8, 2023 at 11:43 pm

    Are there regular 110v hps bulbs that operate safely in a normal wall circuit standard plug that can be use without running it through a ballast? or does this kind of lighting require it to be ran through 220v through a ballast? thanks

  33. Mahmoud ALLAN on February 8, 2023 at 11:43 pm

    Great Video,
    Is it possible to change the mercury lamp with MH? without changing ballast and capacitor.

  34. Sparky1500 on February 8, 2023 at 11:43 pm

    Another reason high pressure sodium lamps use a ceramic arc tube instead of quartz, is not just because aluminum oxide ceramic can withstand higher heat, but hot sodium is very reactive and chemically attacks and degrades glass and quartz, and aluminum oxide ceramic was found to be the only material that can remain transparent, while resisting temperatures around 2,300°F and being chemically inert with sodium.

    When the low pressure sodium vapor lamp was introduced in the 1930s it was already known that efficiency and color rendering could be improved by increasing the temperature and pressure in the arc tube, but no material was suitable. So in 1955 General Electric discovered aluminum oxide ceramic, and in the late 1950s, built the first prototype high pressure sodium lamp. Available commercially around 1965, by the 1970s they have almost completely replaced mercury vapor lamps used for street lighting.

  35. Daniel Wilson on February 8, 2023 at 11:45 pm

    He is really intelligent

  36. Icebreaker L. on February 8, 2023 at 11:47 pm

    Clear as mud. Go and take engineering classes you’ll fail all of them.

  37. Rager on February 8, 2023 at 11:47 pm


  38. David Sullivan on February 8, 2023 at 11:48 pm

    This is very helpful for me. Thank you for sharing.

  39. Frank Reynolds on February 8, 2023 at 11:48 pm

    I really want him to smash the bulbs

  40. MrNater1978 on February 8, 2023 at 11:51 pm

    hey bud…my yard light quit working..i tried to replace the bulb I got one of the middle halide was to replace it but still not working. been looking at the innards of .. it only has a ballast and the daylight sensor.. there is no capacitor in there.. it worked at one point but now it’s not do you have any ideas?

  41. BIRD KING on February 8, 2023 at 11:51 pm

    Replaced lots of the solid state starters and ballasts about thirty years ago. And some of them took long time to start glowing.

  42. Edmonton Rails on February 8, 2023 at 11:53 pm

    Best video I’ve seen explaining the different lights. It’s a common misconception that LEDs are more efficient than sodium lights. LED streetlights "save energy" by lighting a smaller area to a lower level of luminance, a practice justified by the thoroughly-debunked application of a Scotopic/Photopic ratio. In reality LEDs, especially those that produce warmer light, are less efficient at producing light than sodium vapor lamps.

  43. Corpse1984 on February 8, 2023 at 11:57 pm

    Do you have a troubleshooting video on these lights? 347v to be specific

  44. Simon Merciers on February 8, 2023 at 11:57 pm

    Working with MH requires a transformer/capacitor or transformer/ballast? Does a ballast act similar to a capacitor? Could a video be made for wiring MH transformer with a capacitor for inputs of all common voltages and outputs?

  45. Joseph DESTAUBIN on February 8, 2023 at 11:59 pm

    I’m pretty sure that if there was not an inert gas inside the inner chamber It would last only seconds perhaps only minutes. Oxidation does quite the job at high temperatures on all kinds of metal.

  46. T Reed on February 9, 2023 at 12:01 am

    I should’ve stayed in school, cuz I can’t find murcury anywhere on the periodic table

  47. Kathryn Nowack on February 9, 2023 at 12:01 am

    Hey Dustin, I’m a union stagehand who works in electrics, but my passion is follow spot operation. Most spots operate on a HID lamp.

    It would be amazing to see a video about carbon vs xenon lamps.