Flourescents fittings t8 and t5, whats the difference?

[happyhero]

Hi I have a couple of 4ft florescent fittings in my workshop and they are the high frequency type. They are both playing up so I want to buy some new ones and it started off simple but now I am confused. I have a box of 25 4ft tubes so I wanted to stick with the same size but on looking for HF fittings I see there are T5's and T8's in 4ft and one is 36w and one is 28w. My tubes are 36w and my local electrical place has a good price on the fittings but they are sold as the 28w type, does this matter i.e. can I use the 36w tubes in the 28w fittings or does that cause a problem?

Any help appreciated.

 

[AdrianUK]

In a word, YES, it does matter....

The 'T 'number denotes the diameter of the tube in multiples of 1/8" .... so the original 'fat' tubes where T12 ... or 1.5" diameter

The next generation of tubes (which also used better phosphors and gave more light per watt) where T8 ... or 1" diameter

The current new generation of tubes are T5 ... or 5/8" diameter and are even more efficient.

It was possible to replace an 'original' T12 40W 4' tube with the second generation of T8 4' tubes which are 36W and they worked fine with the original control gear.

The new T5 tubes are intended to work with HF (high frequency) control gear and cannot be used in older fittings or vice versa.


To do what you want, you need to buy a T8 4' fitting.

Adrian

 

[RF Lighting]

T5 and T8 tubes have different pin spacings, so T8's will not physically fit a T5 fitting.

 

[securespark]

I wanted to say that.

 

[RF Lighting]

 

[AdrianUK]

T5 and T8 tubes have different pin spacings, so T8's will not physically fit a T5 fitting.

Ah, yes...that's true too....I'd forgotten that!