Can I run a probe start 175w MH lamp on an H39 ballast?

Pros and cons.

I have some mercury fixtures that have ballast that are extremely difficult to get to, to replace. With mercury lamps becoming scarce I'd like to know if I can run probe start MH lamps on them. Or, does anybody know of any led bulbs that will run directly off an H39 ballast. I've seen some that run off MH ballasts but I'm not sure if they'd work on mercury ballasts.

Any info is much appreciated, thank you.

The H39 provides 240V OCV. Probe-start MH lamps requires 380V OCV, so the lamp will have ignition problems. Yo can run 175W probe-start MH lamp on an M57 ballast without problems.

First, nice to see you active again.

Second, I tried running a probe start metal halide in my yardblaster and it cycled. I was told it was because of the kind of ballast in it. From what I hear, you can put an FS2 starter in series with a 240v incandescent lamp and have it connected to the socket as it will create a starting kick that will reliably start a probe start metal halide. If you have a little money to spend, an inexpensive retrofit might be a better option. This way you can run both mercs and metal halides in the fixtures.

It's nice to be back, I know it's been awhile, just so busy with work.

The fixtures in question in fact are at work. They are old mercury recessed fixtures on the outside of the building and the only way to access the ballast is rip a hole in the ceiling. They are basically sealed in this ceiling.

I read somewhere the mercury lamp ban was repealed, is this true? And if so what exactly does that mean, will we see a full return of mercury lamps or the most common types? I'm hoping so, so I can continue to use them in these fixtures. The current lamps are about 5 years old and they are just now starting to dim a bit. I think I'll replace them all soon anyway so they are nice and bright again, with new mercury lamps.

It looks like the ban is repealed indeed. Though i am not following exactly what is going on. See : http://www.lighting-gallery.net/index.php?topic=4549.0

Sometimes installs like this with recessed can and inaccessible ballast are installed by placing the ballast in the ceiling through the hole, then inserting teh can after it. So the ballast can be accessed by removing the lantern

Setups where the balalst is inaccessible can sometmes be installed unsafely in the 1st place - Ballast laying open (without box) in the void, dust or insulation covering the ballast, cables touching it and so on - in which it can be a fire hazard, especially as it ages. Definitely have a peek inside if you can



MH vs Merc starting : The MH can require a bit higher starting voltage but i guess there is an appropriate ignotor (some 700V) to solve this problem, without hacks of starters and incandescents

Cylcling can happen if the MH lamp's arc voltage goes too much up for the installation - In a ballast with lower OCV this means sharper drop in current supplied to the lamp, and can get to the point where the lamp goes out

The ban was repealed, so you will be able to maintain these lights for many more years. I thought they were floodlights or yardblasters, but I know how hard it is to get to ballasts in recessed fixtures (experienced it.)

For many more years, except if you cant get proepr quality lamps.... Take care

I read here some time back about 175W Merc lamps that were made with lower voltage arctubes, that caused overheating of ballasts. In a setup like here such lamp could potentially be a fire hazard in addition to damaging the ballast itself

Second, I tried running a probe start metal halide in my yardblaster and it cycled. I was told it was because of the kind of ballast in it. From what I hear, you can put an FS2 starter in series with a 240v incandescent lamp and have it connected to the socket as it will create a starting kick that will reliably start a probe start metal halide. If you have a little money to spend, an inexpensive retrofit might be a better option. This way you can run both mercs and metal halides in the fixtures.

If the problem is with the MH cycling, the starter won't help anymore.
The starter is helpful only when the only problem is the lamp ignition. If it ignites, the function of the starter is over and you really have to look for another ballast.
I would guess because of the CWA nature (a series LC operated below resonance as the ballasting impedance) of providing higher voltage for the arc reignition after the current zero cross compare to just an inductive impedance (HX transformer and/or series inductor on 240V), it is well possible a cheap HX designed for mercs may have troubles with MH's, while the CWA's will most likely operate the MH's well, once the lamp ignites.