What is happening on the light bulb?

[ranmasatome]

Just wondering...

If my light is a 36 PL light that comes with a 36watt ballast...and i decided to use a 24watt pl light bulb instead, am i over-stressing the bulb?

Will it run warmer?
is the bulb giving out 24watts or is it running over time and giving me more than 24watts?

Is this safe? if there is a fire hazard then i'll revert back to 36watts..or get a 24watt light set.

[hwchoy]

no, the ballast must be higher rating than the tube it drives.

[ranmasatome]

Isn't that the case now?? 24watt tube and 36watt ballast... so how? overdriving it ah?

[taygu]

I have checked with a electrician before, was told that the matching must be within 75% for it to work. It means that if the ballast is 36 watts, the bulb must be between 27 watts and 45 watts. However, over-driving the bulb will cause the bulb life span to be shorter and under driving it will not bring not out the full brightness of the bulb.

This is base on my undertsanding which you may want to confirm further.

[ranmasatome]

Well.. the bulb is a 24 watt bulb.. Which isn't in the 75% range. However, it is still working...that means this bulb is now being overdriven ya??

If i was using a 27watt bulb.. would that mean i am also still overdriving it?? or would it output 27watt?? since this is within the 75% range..

[taygu]

Oh, so the electrician smoke me..

Did a search (http://en.wikipedia.org/wiki/Electrical_ballast & http://members.misty.com/don/f-lamp.html#int0) and found out that the ballast is used to kick start the lamp and also to limit the curent to the lamp.

If I understand it correctly, it means that it is ok to used a lamp that has lower watts than the ballast but if you used a lamp that is having higher watts than the ballast, it will not bright out the full brightness of the lamp.

If any expert knows better, please help.

[ranmasatome]

Well.. it also states that lamps are negative resistance appliances.. which means it will continually draw current until the limit stated by my ballast which is 36watts...so now my 24watt bulb is drawing 36watts??

i can understand what you're saying but that only applies to positive resistance appliances...

So anybody know better?? help please?

[StanChung]

Erm, I don't know much but recently one of my 55W ballast blew and i replaced it with an e ballast that has 40-55W rating. This luminaire was a twin light thing with two ballast.

Comparing the original unblown one, the lightbulb hooked to the new ballast looked dimmer significantly. [the old ballast was rated exactly 55W]