PDA

View Full Version : Bulb diameter question.

Todd
02-02-2008, 07:41 PM
I have a profilux with a dimmable ballast on it. The ballast is a 2 x 54 watt ballast. I wired it with endcaps that fit a normal sized florescent bulb. Now I am looking at getting some different bulbs. From the J and L website any bulbs that are 54 watt are T-5 diameter HO bulbs. Are these the same diameter as the endcaps that I am using, or do normal endcaps accommodate different sizes?

Kind of a silly question considering I made it all myself, but I cant find any info about this online.
KrazyKuch
02-02-2008, 09:27 PM
I am guessing that buy that when you say normal sized end caps that you are refering to T-8 end caps, and if thats the case then no t-5 bulbs will not fit....you will have to buy some t-5 end caps from J&L!
Todd
02-02-2008, 09:40 PM
I am guessing that buy that when you say normal sized end caps that you are refering to T-8 end caps, and if thats the case then no t-5 bulbs will not fit....you will have to buy some t-5 end caps from J&L!


So the T5 bulbs have a smaller diameter then the T8's? Where do T12's fit into the picture?
PoonTang
02-02-2008, 09:47 PM
the "T" number of the bulbs is the size of the bulb in 8 ths of an inch. Therefore T5 is 5/8 " diameter and T12 is 12/8" . They all have their own specific mounting caps.
Todd
02-02-2008, 09:51 PM
the "T" number of the bulbs is the size of the bulb in 8 ths of an inch. Therefore T5 is 5/8 " diameter and T12 is 12/8" . They all have their own specific mounting caps.

Ahh, awsome. That makes sense. That information is very hard to find!
midgetwaiter
02-03-2008, 01:15 AM
the "T" number of the bulbs is the size of the bulb in 8 ths of an inch. Therefore T5 is 5/8 " diameter and T12 is 12/8" . They all have their own specific mounting caps.

There's a bit more to this.

The diameter is important when using water resistant endcaps as you need the right spacer to ensure a seal. Most of the end caps on the market actually have interchangeable seals if you are going to use a T8 or T12 in them. You should be able to find these somewhere.

The option you have if you don't want to switch your end caps is to track down some T6 HO bulbs. They will be fine on your 54w T5 ballasts and use the same pin placement as a T8/T12 bulb so your end caps would work with the right seals. They are actually really great bulbs but kind of tough to find. Getting T5 end caps might be easier.