Hi all, new to this forum and would consider myself endlessly curious on just about anything electrical. A friend down the street has a box of the Westinghouse H33 street lamp bulbs and I'm just trying to learn more about them. They are 400 watt, about 20,000 lumens. What I have found so far is they use 130 or 135 volts and might or might not have an internal ballast as part of the bulb. I have run across H33 ballast that run on 277 volts.

Don't understand the 130 volts, would think a street lamp would run at the higher voltages.

Would love to get some clarification on the ballast.

And if anyone has any ideas on what to do with them, other then take them to the has mat section of the dump please let me know.

Also - any tips on cleaning, did not want to risk damage to the writing on the top so I did not touch them.

Thanks,Dale   

These run on either H33 or M59 ballasts, which are available in several voltages. Most are multi tap meaning they run on a myriad of different voltages depending on which wires you connect to the mains. This means you can get a proper ballast that will light this lamp from the 120V mains. There is no way to properly light this lamp without a ballast otherwise it will self destruct in an instant.

Thanks for the info. The self destruct sounds scary! Glad I did not try hooking them up.   

Yes, it never happened to me, though. All discharge lamps require a ballast of some sorts, regardless of the type. They have a negative resistance, meaning that as the current flows, the resistance constantly drops, letting more and more current through until something fails, usually the lamp. This happens very quickly, sometimes in a fraction of a second. A ballast provides a means to externally offer resistance to the circuit so that the current is limited and won't destroy the lamp.

As you read posts and picture comments here, you'll get to know about different ballast designs, their advantages and disadvantages, how they work, etc.

Wow ! He has an entire box of them ?

Don't throw them out, whatever you do 

These are historical lamps. If you or your friend don't have a use for them, and you decide you do want to sell/trade any, put a message in the For Sale or Trade board.

Welcome to the site, by the way 

Hi all, new to this forum and would consider myself endlessly curious on just about anything electrical. A friend down the street has a box of the Westinghouse H33 street lamp bulbs and I'm just trying to learn more about them. They are 400 watt, about 20,000 lumens. What I have found so far is they use 130 or 135 volts and might or might not have an internal ballast as part of the bulb. I have run across H33 ballast that run on 277 volts.

Don't understand the 130 volts, would think a street lamp would run at the higher voltages.

Would love to get some clarification on the ballast.

And if anyone has any ideas on what to do with them, other then take them to the has mat section of the dump please let me know.

Also - any tips on cleaning, did not want to risk damage to the writing on the top so I did not touch them.

Thanks,Dale

The 130v - 135v you are referring to is the lamp's arc voltage drop across the operating electrodes. In addition, you can also run this lamp off a 400w M135/M155 pulse start metal halide ballast without the ignitor present in the circuit as well. The lamp you have shown here is extremely rare and is well sought after by many collectors.

Yes he has a box of them, did not count but I think it is one short of a full box.

I'm interested in learning how ballast work, I have a coil/ballast from a high pressure sodium street light that I just tested with my Digital Multi Meter and see the three wires it has are all connected. I had 2.7, 2.8 and .3 ohms. Looks to be an auto transformer. It also had an igniter that I want to try and understand.   

That looks like only part of a ballast. It won't work with that mercury vapour lamp you have. I would try to find a suitable 400W ballast before trying the lamp. Look for ANSI code of either H33 or M59, and for an input voltage of 120V (or multi tap that has 120V among other options, all on the same ballast).

Correct, I had removed the E core for a homemade auto transformer I made more as a learning project then anything else. No intentions to try to use it with the Mercury Vapor bulb. Not even close to the correct size (came from 70 watt HPS) From what I have learned so far it is wired in series and works as an inductor to limit current. The third wire I believe is hooked to the igniter and provides a voltage spike to get things going. But I'm still trying to understand exactly how it works. Will keep reading.   

Dale,

If you're going to sell any of these, I'd definitely be interested. 

BT25

     To understand how a ballast works, you first need to understand how gas discharge lamps (namely fluorescent and HID lamps) work. An incandescent lamp works based on the principle of positive resistance, which means that the lamp must not operate over a certain voltage that is supplied to it. According to Ohm's Law, the current of an incandescent lamp is determined by the voltage that is supplied to it. However, gas discharge lamps function much differently than incandescent lamps. They however function on the principle of negative resistance, which means that these lamps must not have their arcs must not exceed a certain current. If a gas discharge lamp is connected directly to an unballasted mains supply, the lamp will burn out instantly because the lamp will draw an infinite amount of current. Because of this, a device known as a ballast is needed to limit the current of the lamp's discharge. There are many types of ballasts that exist in the world.

     To start off, the simplest ballasts are known as chokes, which are known as "reactors" or "inductors" in some countries. The only function of a choke is to limit the current to the lamp that is connected to it. In order for gas discharge lamps to function properly on a choke, the mains voltage must be at least 1.7 times as high as the lamp's voltage drop across the arc in most cases except for most low pressure sodium lamps, which typically require a mains voltage that is several times as high as the lamp's voltage drop unless a special ignitor is used. A choke typically consists of a single iron core with copper wire wound around it to provide an inductive kick to assist in the ignition of certain gas discharge lamps. To install a choke, you simply wire it in series with the lamp. Chokes are among the most common ballasts in the world because most countries use a mains supply between 220v-240v for most electrical applications, which is a sufficient mains supply for running a gas discharge lamp with a stable arc.

     A second type of ballast that is used to power gas discharge lamps are resistive ballasts. A resistive ballast functions just like a choke ballast except that it does not provide any inductive kick whatsoever. In order for gas discharge lamps to run off resistive ballasts, the mains voltage supplied to them must be at least 2 times as high as the lamp's voltage drop since the absence of an inductive kick makes it more difficult to start gas discharge lamps on lower mains voltage supplies. Resistive ballasts often consist of resistors and incandescent lamps wired in series with the gas discharge lamp. It is true that you can actually use incandescent light bulbs as ballasts for gas discharge lamps provided that you have a sufficiently high mains voltage and that you wire the incandescent light bulb in series with the lamp. In the case with your 400w H33 mercury vapor lamp, you can also use a 240v mains supply and a certain combination of incandescent bulbs wired in series with the lamp to run it properly. This type of ballasting circuit is commonly used in self ballasted mercury vapor lamps and some early fluorescent fixtures such as the Mazda Netaline from the UK, which uses a resistive wire to ballast a F40T12 fluorescent tube off of a British 220v-240v mains supply.

     A third type of ballast is known as an high reactance autotransformer (HX) ballast. These are the simplest and most efficient types of autotransformer ballasts that only consist of a step up or step down transformer and a choke integrated into one complete unit. Those types of ballasts are usually needed whenever you have a mains supply that is too low to sustain the lamp's arc with a choke by itself or a mains supply that is too high for the lamp's internal components to handle. HX autotransformer ballasts are most commonly found in countries that use a mains supply that is between 100v-127v for most electrical applications since most gas discharge lamps cannot sustain an arc at that mains voltage with a choke alone. In addition, some countries with 220v-240v mains for most applications typically use HX autotransformer ballasts for most low pressure sodium lamps due to their high mains voltage requirements or some high wattage gas discharge lamps.

     A fourth type of ballast is known as a constant wattage autotransformer (CWA) ballast. Those ballasts are essentially HX autotransformer ballasts that require a series capacitor to operate the lamp properly. A CWA ballast works by using a capacitor wired in series with the lamp or between the transformer and choke of the ballast to provide better current regulation than HX autotransformer ballasts, choke ballasts, and resistive ballasts.

     I hope that with this information, you can get a better understanding of how ballasts work, daleorlfl. Other people are welcome to elaborate on my explanations since I seem to only have a very basic understanding of how ballasts work due to the fact that I did not take any electrical engineering classes.

Thanks for the info. I'm starting to understand how the ballast work. Looks like the sample from a small HPS lamp I was checking out with the DMM is a Reactor Ballast. Searches on any of the ballast types pulls up a lot. Found a good read at: https://www.cooperlighting.com/s/technical-support/pdf/ballast%20rundown%20streetworks896e.pdf there is a schematic of the Reactor Ballast in this .pdf The ohm reading I got match this one. Turns out the HPS ballast provide a high 2500 volt pulse to start the arc. On the next street over from my house there is a HPS street lamp that comes on for a bit then off and restarts. The .pdf above covers this in case anyone is curious why HPS lamps do this.

 

It's called end of life cycling, due to voltage rise.  The only way to correct this is to replace the lamp.