Author Topic: "Cycling" f15t8?  (Read 2988 times)
Lumex120
Member
*****
Offline

Gender: Male
View Posts
View Gallery

/X rated


UCM30tBQDUECOV6VeG5W87Vg
WWW
"Cycling" f15t8? « on: November 02, 2015, 09:34:14 AM » Author: Lumex120
The f15t8 preheat aquarium light on my fish tank just started flashing on and off randomly. I lifted the cover up, and the lamp's ends would glow red hot, the lamp would strike, and then go out, and the ends would glow again. It seems very similar to a cycling HID lamp. The starter glows when the light is first switched on, but other than that, it doesn't glow. Is this a normal EOL for fluorescents? :-\
Logged

Unofficial LG Discord

Solanaceae
Member
*****
Offline

Gender: Male
View Posts
View Gallery

All photos are brought to you by Bubby industries.


GoL Solanaceae.Keif.Fitz Keif Fitz bubby_keif
Re: "Cycling" f15t8? « Reply #1 on: November 02, 2015, 09:42:07 AM » Author: Solanaceae
Are the ends totally blackened? If so, they're emitter depleted and won't strike as a result.
Logged

Me💡Irl
My LG Gallery
My GoL Gallery

dor123
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Other loves are computers, office equipment, A/Cs


WWW
Re: "Cycling" f15t8? « Reply #2 on: November 02, 2015, 10:29:18 AM » Author: dor123
When an argon T8, short T5 and T12, reaches EOL on preheat circuit, the rectification causes sufficient voltage to flow the glow bottle of the starter, causing it to interrupt current to the lamp to preheat the electrodes and than restrike it in a random periods. This is the normal EOL behavior of a preheat ballast + glow starter. I think since most of your ballasts in the US, are self-starting (Rapid-start, Slimline and trigger start), you never seen an EOL behavior of the more common setup in Europe (Series choke + starter), which the american preheat is the same, with the only difference is that the ballast is autotransformer.
Logged

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.

Lumex120
Member
*****
Offline

Gender: Male
View Posts
View Gallery

/X rated


UCM30tBQDUECOV6VeG5W87Vg
WWW
Re: "Cycling" f15t8? « Reply #3 on: November 02, 2015, 11:00:03 AM » Author: Lumex120
Are the ends totally blackened? If so, they're emitter depleted and won't strike as a result.
The ends have some blackening but not much.

Quote from Dor123 on 9:29 AM
When an argon T8, short T5 and T12, reaches EOL on preheat circuit, the rectification causes sufficient voltage to flow the glow bottle of the starter, causing it to interrupt current to the lamp to preheat the electrodes and than restrike it in a random periods. This is the normal EOL behavior of a preheat ballast + glow starter. I think since most of your ballasts in the US, are self-starting (Rapid-start, Slimline and trigger start), you never seen an EOL behavior of the more common setup in Europe (Series choke + starter), which the american preheat is the same, with the only difference is that the ballast is autotransformer.

Makes more sense. Still was weird how it was similar to an HID lamp cycling.:-\
Logged

Unofficial LG Discord

dor123
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Other loves are computers, office equipment, A/Cs


WWW
Re: "Cycling" f15t8? « Reply #4 on: November 02, 2015, 11:13:10 AM » Author: dor123
This is how an EOL fluorescent lamp behaves on a series choke + glow starter: http://www.lighting-gallery.net/gallery/displayimage.php?pos=-110634
EOL F36T8 behaves slightly different on preheat, because of the higher starting voltage of their krypton buffer: http://www.lighting-gallery.net/gallery/displayimage.php?pos=-106469
Logged

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.

Solanaceae
Member
*****
Offline

Gender: Male
View Posts
View Gallery

All photos are brought to you by Bubby industries.


GoL Solanaceae.Keif.Fitz Keif Fitz bubby_keif
Re: "Cycling" f15t8? « Reply #5 on: November 02, 2015, 11:48:12 AM » Author: Solanaceae
I saw somewhere where a person here had a vintage fluorescent that had an air leak, and it would cycle like a hid lamp, but not quite like the way you describe, Zarlog.
Logged

Me💡Irl
My LG Gallery
My GoL Gallery

Lumex120
Member
*****
Offline

Gender: Male
View Posts
View Gallery

/X rated


UCM30tBQDUECOV6VeG5W87Vg
WWW
Re: "Cycling" f15t8? « Reply #6 on: November 02, 2015, 12:03:01 PM » Author: Lumex120
This is how an EOL fluorescent lamp behaves on a series choke + glow starter: http://www.lighting-gallery.net/gallery/displayimage.php?pos=-110634

That is very similar to what mine is doing, but the delays are slightly longer than they are in that video.
Logged

Unofficial LG Discord

funkybulb
Member
*****
Offline

Gender: Male
View Posts
View Gallery


Re: "Cycling" f15t8? « Reply #7 on: November 02, 2015, 02:12:24 PM » Author: funkybulb
Yes this lamp ran off of emitter when that happens the cathode glows red hot. Also it good way get those starter stuck.
Logged

No LED gadgets, spins too slowly.  Gotta  love preheat and MV. let the lights keep my meter spinning.

Lumex120
Member
*****
Offline

Gender: Male
View Posts
View Gallery

/X rated


UCM30tBQDUECOV6VeG5W87Vg
WWW
Re: "Cycling" f15t8? « Reply #8 on: November 02, 2015, 02:19:33 PM » Author: Lumex120
Yes this lamp ran off of emitter when that happens the cathode glows red hot. Also it good way get those starter stuck.
I replaced the lamp as soon as it cooled off (it was also unusually hot, much hotter than it usually is) with another aquarium lamp. The old lamp was 4000k and had a nice color, but the new one is 18000k and makes the fish look weird, so hopefully I can find another in 4000k.
Logged

Unofficial LG Discord

Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: "Cycling" f15t8? « Reply #9 on: November 02, 2015, 02:38:17 PM » Author: Medved
Hot lamp means there could have been an air leak, poisoning the lamp inner atmosphere. It causes the arc voltage to increase, hence the higher losses (so temperature) and then starter cycling.
How long it has been cycling? If for mote than few hours, I think the starter will be quite worn out, so I would replace it too (degrading starter tend to kill lamps)...
Logged

No more selfballasted c***

Lumex120
Member
*****
Offline

Gender: Male
View Posts
View Gallery

/X rated


UCM30tBQDUECOV6VeG5W87Vg
WWW
Re: "Cycling" f15t8? « Reply #10 on: November 02, 2015, 02:48:20 PM » Author: Lumex120
Hot lamp means there could have been an air leak, poisoning the lamp inner atmosphere. It causes the arc voltage to increase, hence the higher losses (so temperature) and then starter cycling.
How long it has been cycling? If for mote than few hours, I think the starter will be quite worn out, so I would replace it too (degrading starter tend to kill lamps)...

It was doing this for about 45 minutes at the most, because I didn't notice until I came in the room. The starter looks ancient too, so I plan on replacing it soon. As for the air leak, that seems to be the most likely cause, since it was so hot it hurt to touch it.
Logged

Unofficial LG Discord

Print 
© 2005-2024 Lighting-Gallery.net | SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies