ballasts

Where are you located? What is your line voltage?

--- sam | Sci.Electronics.Repair FAQ:

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Are you sure the ballast is wired right? Most North American twin lamp autotransformer ballasts wire the lamps in series, the output of the secondary is on the red and blue wires, the yellow wires are only a small winding to provide cathode heat to the middle cathodes.

Yellows on one side, one lamp to reds and another if present to blues on the other sides. 120 vac. I checked voltages except the actual drive, supposed to be about 380 vac unloaded. I will measure that next. I had to defeat contacts to get access. Its all in a big hood. It worked, now it still does ot even with new parts. I don't imagine there is a problem with the socket since the filiments light. Its also a UV lamp.

I wired up a strobe once. It would not work in the dark. As soon as you gave it enough light it would fire.

greg ]

I am reading the lamp FAQ.

The measurements on the orginal ballast are off. I may have a bad new ballast

greg

I am looking at the orginal ballast and another single lamp with RR BBuWG

On the later I measure HV when the lamp in inserted, but there is no HV open, and the lamp is a perfectly working model. I'm not sure I understand the no HV concept. Its not present on the orginal non working model 2 lamp ballast.

greg

I ordered another ballast, slightly different. The second ballast didn't seem to have enough oomph. I did read a open starting voltge almost 200 volts. It just got loaded down with the tube even though its for a bigger tube ??

I had wonderd if a UV lamp has slightly different requirments, as I found an old separate listing for Advance UV ballasts. Don't know.

greg

ot

Look for an AC disconnect on one of the socket pins.

--- sam | Sci.Electronics.Repair FAQ:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

two

the

since

gave

ballast

Don't know for sure but a UV lamp is just a normal lamp without the phosphor and probably in a quartz envelope?

BTW, how sure are you that the lamp is good? Sorry if this was mentioned already.

--- sam | Sci.Electronics.Repair FAQ:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

I am not totally convinced they are good. We tried 3.

greg

That won't work unless the ignition capacitor within the ballast is shorted, which I've seen once, the yellows go to an isolated filament winding, they're not part of the ballast secondary. Put the red wires on one end and the blue wires on the other and the lamp will light. Better yet, use a ballast designed to operate a single lamp, they're cheap.

That might have worked. The orginal ballast was bad. The replacement just did not do the job. I fixed the problem when I installed an instant start ballast. The guy at Grainger suggested a lower power single unit. I had to join the reds and the yellows, as the 600 volt starting voltage apparently does not need filiments.

greg

small

supposed

seem

I assume you have tested for continuity of the filaments at both ends?

--- sam | Sci.Electronics.Repair FAQ:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

Did you even read what I posted? There's a capacitor between the yellow wires and either the red or blue wires to help ignite the first lamp in the series chain, you'll measure a voltage between the other colors and the yellows because of this, but it'll load down with a lamp connected. It sounds to me like the ballast is behaving precisely as it should, you're just not connecting it right. It's not designed to operate a single lamp, it connects both lamps in series, if one is not there, the other will not light.

That will work, though if the lamp is not designed for it, it will fail quickly due to cathode sputter. Instant start ballasts need lamps specifically designed to be operated without supplemental cathode heat.

Did you even read what I posted? That sounds like good info, but I was trying to go by the orginal installation, which was exactly as I was trying to do,. The two blue wires had wirenuts and went noplace. The orginal ballast had no filiment voltages present. The new ballast lit the filiments very nice, and now after the third ballast, everything is bluish.

greg

I'll see if I can come up with a number.

greg