Is HPS Pulse-Start? If so, Them my ballast could possible run Pulse-Start MH bulbs, and potentially Moon Pulse lamps.
I have several threads about similar problems in my ongoing quest to know what my electronic ballast can run.
Maybe my ballast can run PSMH bulbs but generalizes it to "MH/HPS".

HPS is pulse-start as it requires an ignitor to start. But it have a different arc voltage/current than Eye Moon Pulse and american pulse-start MH lamps, so it would be underdriven on a pulse-start ballast.

HPS is pulse-start as it requires an ignitor to start. But it have a different arc voltage/current than Eye Moon Pulse and american pulse-start MH lamps, so it would be underdriven on a pulse-start ballast.

Good thing my ballast has a  "Super Lumen" mode, It gives 10 to 20 percent more power to the lamp.
But would that be enough?

The OCV (open circuit voltage) of reactor type (single coil) HPS ballasts is far too low to run a metal halide or mercury lamp. The HPS ignitor will just continuously run as the main drive current from the ballast never happens. CWA type HPS ballasts (typically 250w and above) will run metal halide lamps, but they will be overdriven, a 250w MH lamp will be driven at about 300w on CWA 250w HPS gear.

The OCV (open circuit voltage) of reactor type (single coil) HPS ballasts is far too low to run a metal halide or mercury lamp. The HPS ignitor will just continuously run as the main drive current from the ballast never happens. CWA type HPS ballasts (typically 250w and above) will run metal halide lamps, but they will be overdriven, a 250w MH lamp will be driven at about 300w on CWA 250w HPS gear.

What does CWA mean? I need that to understand your post.
And are electronic ballasts any different? Could mine run a PSMH (I want CMH) lamp because it can run HPS?
I'm just getting confused.
And my ballast says MH/HPS,But you say HPS bulbs will be overdriven on MH ballasts, But my ballast is an electronic and is specified for HPS too.

Mercury lamps can be underpowered quite a bit without bad effects. So for example, 400W MP might be fair match for 250W HPS gear - Gotta check and calculate. Actually dont need the MP either, use ordinary Merc lamp and connect without the ignitor



US Mercury and Probe MH lamps are identical in current ratings



Europe HPS and Worldwide Pulse MH are identical in ratings

If you have any HID ballast rated for Europe HPS lamps, it will run properly Pulse MH or MP. Except that some HPS ignitors have hard time starting a MH, but if it starts, itll work ok



US HPS lamps are a type of their own

Up to 150W S55 (including S55) they can't run much anything other than their HPS lamp (or maybe some VVVHO 2ft Fluorescent tube....Does such thing exist at all ?). 150W S56 and above are high OCV ballasts, similar to those of Merc / ProbeMH / PulseMH, but not ther same ratings. But you can count on underpowering a bit a Mercury lamp, as long as you dont overload the ballast with a too low arc voltage lamp



Super lumen mode on ballasts : Carefull. In many "plant grow" sort of ballasts this may be a feature added for the sake of having such feature, while the ballast itself is not really capable of withstanding such power in the long term (so working too hot, isolation degrading over time, and eventual failure)

Electrically the CWA is a step up transformer, series saturable inductor and a capacitor.
The inductor and transformer are integrated into one magnetic component in the form of a transformer with asaturating magnetic shunt between the primary and secondary.
The transformer functionality steps up the mains voltage to the level needed for operating the lamp, for pulse start MH it is around 220..250V.
This then feeds the lamp in series with mainly the capacitor, acting as the main ballasting reactor.
The inductance in series reduces the capacitive reactance (because inductive reactance has an opposite phase), so increases the operating current.
But as the current increases, more of the inductor (in fact the magnetic shunt) saturates, so the inductance get reduced. Because the inductance reduces the ballasting reactance, the lowering of that inductance increases the final reactance and so prevents the current from further rising and so keeps it rather constant over quite wide range of the voltage drop across the complete ballast impedance.
So it is a constant current source, independent on both mains and load voltage (within quite wide limits).
This concept was first designed for the MV lamps, which use to have it's arc voltage fixed and not dependent on virtually anything. So the only remaining external variable on the system was the actual mains voltage. Since the lamp has always the same voltage drop, a constant current means a constant power delivered to the lamp, independent on the mains voltage. Hence the name of "Constant Wattage Autotransformer".

Now when used with other lamps, the CWA keeps doing what the concept is designed for: Maintaining the constant current. But when the lamp had a habit of increasing the arc voltage when the temperature increases (many HPS, as well as CMH lamps), the constant current feed means the increased arc voltage causes an actual increase in the power delivered to the lamp. And because extra powerr means more heat and that higher temperature. So a positive feedback is formed. So there becomes quite some risk of a runaway, when this feedback becomes too strong.
To fight this there are two options:
First make the lamp so, the arc voltage does not respond to the power variation. One way is uto use an unsaturated vapor lamp concept (after all, MV's are of that form; but some HPS are designed that way as well). And option is to make some form of pressure regulating cold spot temperature stabilization within the lamp, usually in the form of an external amalgam reservoir. This was used quite frequently with HPS designs - the small dark metal "bottle" was cooled by IR radiation, which has very steep function of the radiated power vs the temperature, so even with large power change, the temperature does not change that much. Plus as it is kept rather separate from the arc, it does not respond to the direct radiated heat from the tube, what means the heat transfer to that cold spot is not following the lamp power (the arctube temperature follows the 4'th root of the power, but the heat transfer follows just linear thermal resistance rule), so the net result is the arc voltage changing only a little with the actual lamp power, so it remains stable even with the constant current ballast characteristic.

And the second way to get thermally stable setup is to make the ballast load characteristic not a constant current, but more sloped (higher arc voltage causes lower arc current), so keep the power less dependent on the actual arc voltage. But that means departing from the CWA concept.
One way for that is just a series reactor (or if the mains voltage is not sufficient, integrate it with the step up transformer into the "HX transformer" form). This is the simplest way, but lack the ability to absorb mains voltage fluctuations. So it is suitable only for places with sufficiently stable mains voltage (mainly indoor applications or close to buildings).
This is used mainly for the pulse start MH's, as these have no means of pressure regulation as possible with the HPS, just because the complete arctube (mainly the coldest spot) has to operate at way higher temperature. And because it is the simplest ballast form (the HX autotransformer), it is used for the cheap MV yardblasters or similar.
If the mains voltage is varying and yet the CWA can not be used (because of the lamp characteristic), a most complex magnetic regulator ballast was invented: It contains two parts:
First it is the voltage stabilizer. It is in the form of a HX transformer, where across the sewcondary is a resonating capacitor and the secondary core is saturating. At low voltages the secondary does not saturate, so the series LC (the leakage inductance plus the capacitor) are in tune, so boost the voltage. As the voltage rises, the secondary core section saturates, so detunes the LC, so it stops boosting the voltage, keeping that voltage constant, regardless of the mains.
Then second part is a high leak inductance coupling, making the effective ballasting impedance between the stabilized voltage and the lamp. As this is in fact equivalent to the HX autotransformer and/or series reactor, it ensures the stable lamp operation. It is fed from the stabilized voltage, so no input variation.
And as with previous, all the magnetic functions are integrated into one component, this time with a three coils  with magnetic shunts between them.The first connects to the mains supply, the second to the resonant capacitor and 3'rd to the lamp. The first plus second then act as the voltage stabilizer, the 2'nd and 3'rd as the lamp ballast.

Now the electronic: These are usually quite complex regulators (either DC, or HFAC), where is not that much extra complication to first suppress all the mains variations and 2'nd form any load shape desired for a given particular lamp type. On top of that they used to be equipped with quite some monitoring features, which are designed to respond to the lamp aging - e.g. alter the characteristic so, it compensate the lumen depression on an aging lamp, identify the power rating of the connected lamp, so allow the ballast to adopt to it, so bring to it's user a freedom to change the lampp wattage just by replacing the lamp. Or shut down a lamp, that is deemed as too likely to fail in an unpleasant way.
All these make the electronic ballasts really specific only for the designed lamp types, so more difficult to use for another lamp type (even when the ballast characteristic would be compatible, the other lamp may be evaluated as faulty and so the ballast may refuse to operate it).
As the characteristic may be virtually any shape, it really depends on the actual ballast make/model, whether it is usable for something different than it is designed for or not.

Mercury (MoonPulse) are the lowest common denominator of all HID lamps - Flat V/Temp and V/I characteristics, accept quite wide margin of arc currents without damage, and so on. Would they be a problem with any (even Electronic) ballast ?

So the impression I'm getting is that I can't run a PSMH lamp on my ballast unless it's a very simple one.
But I can run a Moon Pulse? Or MV?

I see you're located in the USA. So, unless you're after some kind of unusual or specialized setup (such as aquarium and grow lights) if you match the ANSI codes on both the ballast and the lamp, you should be good. I believe some models of grow lights and aquarium lights have ANSI codes as well. The only exception being newer probe start MH ballasts that cannot have mercury lamps listed but can run them no problem (a legislation issue).

As far as the Moon Pulse lamp goes, it is designed for a pulse start ballast and should have a proper ANSI code for the PSMH ballast it is designed to run on.

As others have already said, unless you are into European gear and lamps, HPS and MH are not really interchangeable.

I see you're located in the USA. So, unless you're after some kind of unusual or specialized setup (such as aquarium and grow lights) if you match the ANSI codes on both the ballast and the lamp, you should be good. I believe some models of grow lights and aquarium lights have ANSI codes as well. The only exception being newer probe start MH ballasts that cannot have mercury lamps listed but can run them no problem (a legislation issue).

As far as the Moon Pulse lamp goes, it is designed for a pulse start ballast and should have a proper ANSI code for the PSMH ballast it is designed to run on.

As others have already said, unless you are into European gear and lamps, HPS and MH are not really interchangeable.

My ballast says nothing about ANSI codes anywhere, It just says "MH/HPS".
Anybody know anything about my ballast? It's a Lumatek LK400.
Here's a link.

Oh, I see. That is a special grow light or aquarium ballast. I notice they have a toll free telephone number on their website. You could always call and ask. I'm guessing, however, that any PSMH of appropriate voltage would work with this ballast. Normally they have a selector switch for HPS and MH types, so you should be good to go.

Oh, I see. That is a special grow light or aquarium ballast. I notice they have a toll free telephone number on their website. You could always call and ask. I'm guessing, however, that any PSMH of appropriate voltage would work with this ballast. Normally they have a selector switch for HPS and MH types, so you should be good to go.

I'm afraid to call that number.
And you can't change from HPS and MH, Just the wattages.
Does it matter that it says "MAX. 4000V"?

Electronic ballasts rated for both HPS and MH do exactly that, they can properly run both lamp types granted they are the same wattage. Electronic is a completely different animal than magnetic. Most combinations that would never work with magnetic gear do just fine on electronic, because thats what they were designed to do. I have a 250w electronic ballast that is rated for any 250w HPS, PSMH, CDM, and HMI...how about that for versatility!

With HPS or MH magnetic, your lamp interchangeability options are basically nil. Some situations work, but for the most part the ballast's ANSI code is about all it will correctly operate. Mercury lamps will operate on MH ballasts of the same wattage, but thats about it. This is why many companies make MH conversion lamps to retrofit existing HPS ballasts, or conversion HPS lamps that work on MV or probe MH ballasts.

The only situation I know of a PSMH will work normally on an HPS ballast are the 250w ANSI M80 rated lamps, these lamps arent listed as conversion lamps yet operate on the exact specs of a 250w S50 CWA. The now out-of-production M80 ballasts are basically the same specs as an S50... I never understood the application or reason behind the M80 ballasts and lamps

So, Let's get a final answer, What lamps can this ballast run other than MH and HPS?