Re: F40T12 NPF ballast « Reply #1 on: April 12, 2013, 12:39:09 AM » Author: Medved
The F32T8 have higher arc voltagethan the F40T12, what lead to lower lamp circuit currents, so reduction in the power dissipation in the secondary winding. With HPF ballast this mean the phase angle become not so well compensated anymore, so cause higher current in primary winding, what lead frequently to overall increase in ballast losses. But the NPF does not use any compensation at all, so thereduction of the secondary current mean a reduction of all currents in all windings, so reduction on the power dissipation, so such ballast does run cooler.
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	Re: F40T12 NPF ballast « Reply #2 on: April 12, 2013, 02:18:09 AM » Author: dor123
So in NPF rapidstart F40T12 ballasts, F32T8 can retrofit T12 lamps, and in HPF rapidstart F40T12 ballasts, F32T8 can't because of ballast overheating?
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Please forgive me if my choice of my words looks like offensive, while that isn't my intention.

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	Re: F40T12 NPF ballast « Reply #3 on: April 12, 2013, 07:33:32 AM » Author: funkybulb
@ dor123 normal powerfactor ones runing about apearence power of 25 watts. so F32 is closer to that range  and the 4 foot 25 watt shoplight tube is also same gas fill as 40 watt T12. but but diffent cathode contruction.
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	Re: F40T12 NPF ballast « Reply #4 on: April 12, 2013, 11:44:14 AM » Author: Medved
But there could be ignition problems with the F32T8: The thinner format and the krypton fill ask for higher striking voltage, so it may be above what the ballast could deliver. The NPF have normally (with the rated lamp) higher losses than the HPF for the same real power, what is usually "compensated" by the use of lower transferred power. The lower power then become handy for home use, where the lower intensity light source is desired (the tubes are usually closer to the user)
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	Re: F40T12 NPF ballast « Reply #5 on: April 12, 2013, 03:04:01 PM » Author: dor123
Quote from: Medved on April 12, 2013, 11:44:14 AM But there could be ignition problems with the F32T8: The thinner format and the krypton fill ask for higher striking voltage, so it may be above what the ballast could deliver. Medved: F32T8 have the same gasfill as the F40T12 (40W T12): Pure argon. Don't confuse between the american F32T8 and the european 36W T8: They are totally different types of fluorescent lamps. The F32T8 wouldn't be able to strike at rapidstart at all if it would filled with krypton.
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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.

	Re: F40T12 NPF ballast « Reply #6 on: April 13, 2013, 12:56:17 AM » Author: Medved
The US F32T8 do have way higher ignition voltage and therefore they really do not operate on most F40T12 RS ballast, or at least operate only at higher temperatures. Unlike the European F36T8, the F32T8 are not designed to be electrically compatible with the F40T12 (even when on some ballast they could run somehow). That is the reason, why the F40T12 are still widely sold in the US, where is no direct replacement available, but for long time not anymore in the EU, where the F36T8 could be used in majority of F40 fixtures without any modification.
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