Volts

[readydave8]

What is voltage feeding these lamps? Just getting crazy readings from volts meter, kinda like output of fluorescent ballast

 

[ModbusMan]

45 watts / 6.6 amps = 6.8 volts, which "feels" about right given that it looks like a small signaling or panel indicator lamp.

 

[infinity]

If these are airfield type lamps they are typically wired in series with constant current of 6.6 amps.

 

[ModbusMan]

Infinity might be on to something... The Osram spec page specifically calls out airfield operations.

 

[infinity]

These airfield light systems use constant current regulators, 5kv cables, and are wired in series. Here some basic info.

Series Lighting Circuitry: Why Use It?

Although some campus-type facilities use it, series lighting continues to dominate airfield lighting applications. But what exactly is it, and when should you use it?Just imagine...

www.ecmweb.com

 

[n1ist]

For airfield lighting, they use a constant current series loop with a transformer at each light. The lights themselves aren't in series since a burned out bulb would kill the loop.

Edison *did* use a series light bulb loop for street lighting, but used special bulbs that had a piece of paper between the leads feeding the filament. When the bulb burned out, the high voltage would pierce the paper and spot weld the leads. Same like the hairlike thread wound around the filament support in series Christmas bulbs. As long as you don't have too many bypassed bulbs, you are fine.

 

[readydave8]

Yes this is a runway, new lighting system soon but trying to keep old one working until new system comes

We got most of the lights working by changing lamps and sockets, a few new pigtails

3 still not working, I think 2 because bad transformer. If they insist on these 3 working, I'm considering saying I'm not qualified to go further

 

[ggunn]

For airfield lighting, they use a constant current series loop with a transformer at each light. The lights themselves aren't in series since a burned out bulb would kill the loop.

Edison *did* use a series light bulb loop for street lighting, but used special bulbs that had a piece of paper between the leads feeding the filament. When the bulb burned out, the high voltage would pierce the paper and spot weld the leads. Same like the hairlike thread wound around the filament support in series Christmas bulbs. As long as you don't have too many bypassed bulbs, you are fine.

I sometimes use white Xmas tree lights for general lighting. Each bulb that burns out increases the Vd across every other light in the string, and there is an avalanching effect as they burn out faster and faster until the last few all burn out at once like a camera flash. The first time I was in the room when that happened it gave me a bit of a start.