Hey everyone some of you may know that I received 2 ov-25 silverliners a few days ago. And yes they do work but there is a problem. They cycle for some reason. I don’t think it is the bulb maybe the ballast? Whenever I lay them on the ground they stay on longer but when they stand up they do not stay on for very long. It doesn’t usually happen all the time laying down but standing up it will. I’m just trying to figure out why they are doing this. I ordered some new 400W MV bulbs so maybe that will help. Anyone that could help me on this that would be awesome! Thank you

Themally protected ballasts overheating (fault with the ballast or capacitor) ?

Failing capacitors having random breakdowns ?

Wrong supply voltage ?

Themally protected ballasts overheating (fault with the ballast or capacitor) ?

Failing capacitors having random breakdowns ?

Wrong supply voltage ?

Ballast sound very quiet and never get overheated. I don’t think I have the wrong type of voltage because it’ fires up just like a regular mv bulb would. It’s 120V. May need to clean both ballast.

A good place to start is verify the power with a power meter. Also, lamp voltage and current if you're comfortable around that sort of voltage. If nothing else, it gives you a quantitative base line to monitor any potential fixes you want to try.

First check the socket connections: When cold, it works. When laying ion the ground, the lamp heat does not reach the socket, so it remains cold. But when put into normal position, the lamp heat warms up the socket, its materials expand, loose contact, so extinguish the lamp and so on. Dont forget this could well be the main reason why these fixtures were put out of service in the first place...
I have seen many sockets which may appear as having good pressure on all internal connections when you are examining it without the lamp, but that pressure often disappears once the lamp is put in. Mainly all the riveted connections there.

Then check the ballast OCV and then the lamp current.
OCV has to be at least 220V (for MV-only rated ballast) or 300V (MV and MH rated ballast), generally it has to match what the ballast datasheet says. If it differs (and the diference can not be explained by the mains voltage difference), the ballast is most likely faulty.

Lamp current has to be around 3.25A (+/-10% reading is normal, mainly due to nonsinusoidal shape), the voltage measured across the lamp has to be in the 136V ballpark.


What type of ballast it uses?
If CWA, look for capacitor defect - check if it isn't swelling, if it does not warm up (capacitors should not generate any heat), measure its capacitance (if you do not have capacitor meter: Connect in series with an incandescent to the mains, measure voltage across the cap and current, then calculate the reactance and so the capacitance).

If HX: Check, whether the extinguish is not correlated with some high load starting (AC compressor,...). HX use to be sensitive to voltage dips caused by high inrush currents of high power motor loads. Also HX is more sensitive to lamp cathode eventually going bad...

Are Mercs on HX more sensitive to dips than Mercs on series choke on 230V ?

Are Mercs on HX more sensitive to dips than Mercs on series choke on 230V ?

If the OCV of the HX is about 230V, then not. In fact mz main experience comes from the series choke on 230V and a woodchipper: The lamp (Tesla RVLX80, on a VS choke ballast) extinguished even when I just put a bit thicker branch into the chipper, the chipper used an induction motor with a run capacitor phase shifer (so huge current variations on varying load)...
Truth is, replacing with a new Sylvania (European, so SLI lighting, not Osram) lamp, the problem disappeared.

It is the CWA (or a series LC as an equivalent on 230V mains), which is "unusually" immune towards voltage fluctuations...