What will happen if I drive a 15W lamp on a 17W ballast? « on: May 17, 2018, 03:01:54 PM » Author: F96T12 DD VHO
Btw, when I ask "What will happen" I'm asking about the lamp and/or the ballast Here's the story: I have a 2' fixture but I don't have a F15 fixture to drive a TL-D 15T8 (F15 T8 BLB), so the 2' fixture I have has a F17 ballast in it I'm going to take the ballast out and put it on a board and put the lamp holders according to length (I have not done this but I plan to, just asking you guys before I take action and possibly ruin a lamp)
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	Re: What will happen if I drive a 15W lamp on a 17W ballast? « Reply #1 on: May 17, 2018, 07:34:59 PM » Author: xmaslightguy
Assuming its an electronic ballast, it'll light @ around 13w. No harm will come from a short test Look at the ballast and see what lamps it lists... (in particular look for F15T8 or F13T8-18" )
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	Re: What will happen if I drive a 15W lamp on a 17W ballast? « Reply #2 on: June 04, 2018, 05:52:41 AM » Author: suzukir122
What kind of ballast is it? Regardless, it's only a 2 watt difference. More than likely, no harm will be done. Even if it be a low, normal, or high power factor trigger start ballast, (magnetic) and even if your lamp is the energy saving alternative to the typical 15watt lamp (like the FO13T8, for example) you still should be alright.
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	Re: What will happen if I drive a 15W lamp on a 17W ballast? « Reply #3 on: June 05, 2018, 08:55:20 PM » Author: streetlight98
The only thing you'd probably have to worry about is shorter lamp life (particularly with frequent switching) since F15T8s are preheat lamps, so they're not built with the tougher cathodes that electronic T8s have.
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	Re: What will happen if I drive a 15W lamp on a 17W ballast? « Reply #4 on: June 05, 2018, 09:21:22 PM » Author: funkybulb
F15T8’ is 55 volt 360 mA and  F17 is 70 volt 260’Ma So ballast will underdrive the F15 lamps giving 12-13 watts
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	Re: What will happen if I drive a 15W lamp on a 17W ballast? « Reply #5 on: June 05, 2018, 09:35:35 PM » Author: suzukir122
Yeah F15T8's definitely do not have tougher cathode filaments. I should know... 3 out of 7 of my F15T8's (all running on HPF Trigger Start ballasts) are currently EOL. 2 more of them are noticeably close to EOL... I bought all of those lamps from Ebay only a year ago, with most of them being unused. When those two lamps that I've previously mentioned reach their EOL, that will leave only two lamps working, out of 7. I plan to replace all 7 lamps with T12 after that.
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Interests:
1. Motorcycles, Cars, Women, and Lighting (especially fluorescent)
2. Weightlifting/staying extremely athletic
3. Severe Thunderstorms of all kinds
4. Food and drinks. So gimme them bbq ribs
Lighting has ALWAYS been a passion of mine. I consider everyone on here to be a friend