A question on reducing light

[baranne]

Can I just get a lower wattage tube to replace existing ones? Or do I need to ensure that the ballast can support the range of wattage? I could not find any label on the light to indicate if there is a range that it can support.

[joestoys]

I dont think so- it's safer to use the same wattage bulb that the ballast support.

What kind of light and ballast you refering to? FL or PL.

For FL- i think is standard- 4 ft will be 36-40w, 2ft 18-21w..... correct me if i am wrong as i am also not expert.

[baranne]

I have a PL light with 2 tubes. I tried to remove one but realised that they are put in series so requires both to be installed for it to work.

[joestoys]

if the ballast is for 36-40 watt- use the pl with same rating,

if you fix a lower wattage on 36-40watt ballast, the lower wattage pl might blow.

a simple experiment during school day,

use a 3v battery to light a 3v bulb- It's works
use a 3c battery to light a 1.5v bulb- It's blow/ blasted.

So i think it applies over here for the PL.

[baranne]

Thanks for the reply!

Ok, so better not to use lower wattage tubes in case it blows. I do not want to have pierced fishes from the broken glasses.

[aquarius]

I have a e-ballast which i used to power my two 36W PL tubes. I've now changed the tubes to two 30W FL tubes and i've been using it for months and no problem. Maybe the difference in wattage is not much that's why i've not encountered any problems.

[Mason]

FYI, the magnetic or eballast have +/-5% to 10% tolerances. It does works for 30W but inside there is heat losses and the sin wave is not synchronize with the output wattage. This in long term shorten the life span of the tube. Vice verse.

[joestoys]

FYI, the magnetic or eballast have +/-5% to 10% tolerances. It does works for 30W but inside there is heat losses and the sin wave is not synchronize with the output wattage. This in long term shorten the life span of the tube. Vice verse.

so it's safer and longer life span usinf the same wattage for tube and bullast.

[Dreamgarden]

I have a 55W eballast driving a 36W PL tube for months, so far no problem.
According to Chan(NA), eballast will be able to self adjust to suit lower waltage PL tubes. But lower waltage ballast is not able to drive higher waltage tubes.

Hope this helps.

Regards

[tawauboy]

.................
a simple experiment during school day,

use a 3v battery to light a 3v bulb- It's works
use a 3c battery to light a 1.5v bulb- It's blow/ blasted.
................

voltage and wattage are different. wattage is used to measure the power.
using 3v to light a 1.5v bulb will definately blow it.
however, there are no issues with using a 3w power supply to drive a 1.5w bulb.

............
heat losses and the sin wave is not synchronize with the output wattage. This in long term shorten the life span of the tube.
...........

any publication to substantiate this claim? interested to find out.


a higher wattage e-ballast/ballast will be able to support a lower wattage light tube. however, you will not be able to use a lower wattage e-ballast/ballast to drive a higher wattage light tube.