don93s
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| I was wondering...I have an 18w LPS (SOX) lamp that has low hours. Recently I fired it up and noticed there is metallic sodium stuck behind both electrodes. I've never run it base down so I'm wondering how it got there. I've been running it several hours base up but the sodium doesn't seem to be moving away. Question is...how bad is this and how long would it take for the sodium to attack the electrode seals?
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« Last Edit: August 26, 2011, 08:38:21 PM by don93s »
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SOX55W
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120V 60Hz here!
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| Sodium vapor will condense on the glass behind the electrodes because it's cooler there. The electrodes are sheathed in borate glass to protect them from the sodium, and I believe should generally be ok. Both of my lamps did that after only a few hours, so I'm guessing it's normal and not to worry.
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Bring SOX lamps back!!!
FYI, LED's are NOT the most efficient lighting technology available! Don't know how people keep coming to that conclusion!
My other interests: sports cars, refrigeration, microcontroller projects, computer hardware, and any sort of custom fabrication.
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dor123
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| All the sodium tube made from borate glass, as this glass resistant to sodium.
If the sodium accumulates behind the electrodes when operating in base down, the sodium may attack the seals.
I don't know where the cold spot of the sodium tube is located.
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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Ash
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| Maybe in the spikes it has along the side ?
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don93s
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Sodium vapor will condense on the glass behind the electrodes because it's cooler there. The electrodes are sheathed in borate glass to protect them from the sodium, and I believe should generally be ok. Both of my lamps did that after only a few hours, so I'm guessing it's normal and not to worry.
I took a closer look under a magnifier...and you're right. The electrode supports are coated in glass. I guess as long as the sodium doesn't get above where the coating ends, should be ok. |
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SuperSix
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| Is this a GE SOX lamp by any chance? They seem to suffer badly from this problem and often fail early because the sodium eventually reaches the seals and destroys them.
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Atlas Lamps - Seeing Is Believing!
http://www.youtube.com/user/P42STUFF
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don93s
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Is this a GE SOX lamp by any chance? They seem to suffer badly from this problem and often fail early because the sodium eventually reaches the seals and destroys them.
This is a Mazda lamp made in Belgium. Don't know anything about them though. |
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Ash
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| Mazda HPS / MV made in Belgium around late 80s / early 90s is Philips
I dont know about LPS
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MetalHalideHater
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| My Philips 35w has this, but it has 15000 hours on it. It does not seem to majorly affect it in any way though.
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Medved
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| Till it does not touch the unprotected part of the seal, then it goes quickly...
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No more selfballasted c***
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SOX55W
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120V 60Hz here!
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In my modern philips lamps, the electrode sheaths extend just about up to where the cathode is crimped to the lead wires. It's probably close enough that they stay hot enough to keep sodium from condensing on it. Good info here if you haven't seen it before. |
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Bring SOX lamps back!!!
FYI, LED's are NOT the most efficient lighting technology available! Don't know how people keep coming to that conclusion!
My other interests: sports cars, refrigeration, microcontroller projects, computer hardware, and any sort of custom fabrication.
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AngryHorse
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Rich, Coaster junkie!
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| Sodium behind the cathodes is a normal manufacturing opperation, the old Thorn Linear SLI/H have it here also, it will migrate after a few 100 hours use.
Sodium only causes a lamp to pack up if it gets ON the cathodes themselves, where it distroys the emmiter in the coils.
Some new Philips SOX have sodium on the tube, all around the cathodes, (like a mirror), but once running, migrates to the ends of the tube.
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Current: UK 230V, 50Hz
Power provider: e.on energy
Street lighting in our town: Philips UniStreet LED (gen 1)
Longest serving LED in service at home, (hour count): Energetic mini clear globe: 57,746 hrs @ 15/12/24
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Ash
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| Does the lamp use emitter all the time or only when starting ?
I have a HPS here that is not cycling, but very obviously rectifies (50HZ flicker even when fully run up), i wonder if something similar happened to it
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dor123
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| Ash: SOX uses emissive coating all the time, like in the case of fluorescent lamps.
LPS and fluorescent belongs to the same family of low pressure discharge lamps.
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.
I only working with the international date format (dd.mm.yyyy).
I lives in Israel, which is a 220-240V, 50hz country.
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AngryHorse
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Rich, Coaster junkie!
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| That is correct, they use some on starting, and a tiny amount throughout life when running, its coated onto the cathodes and looks like a white powder.
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Current: UK 230V, 50Hz
Power provider: e.on energy
Street lighting in our town: Philips UniStreet LED (gen 1)
Longest serving LED in service at home, (hour count): Energetic mini clear globe: 57,746 hrs @ 15/12/24
Welcome to OBLIVION
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