T5 light

[Waterloo Kid]

Can you overdrive a T5 bulb like you can a T8. I am getting a twin 54W T5 unit and wonder if I could use a 39W bulb in one of the fittings. Any thoughts?

WK

 

[George Farmer]

Not too sure but I'd imagine it may shorten the effective life of your overdriven tube. That's just an "educated" guess though.

 

[Yenko]

Overdriving does shorten the life of the tube, but not dramatically. If you wanted to bother, you could use a setup that uses overdriving to get more light out of your bulbs.

Say you had 4 sockets, and 2 were overdriven 2x. You'd put new bulbs in the non-overdriven sockets and the old ones would rotate to the overdriven sockets, which will burn up their remaining lifespan faster but you will still get good light intensity out of them.

 

[Silly me]

but......

you cant overdrive any tube by driving a 39w tube with a 54w balast....

nor can you overdrive any tube with a magnetic balast

You overdrive a tube by dubbling up the connectors of a electronic balast.. Most electronic balast can drive 2 or 4 tubes.. so you connect both the connectors of the 2 tube balast onto a single tube.. or all four connectors onto 4 tubes balast onto 2 tubes.. or all four connector of a 4 tube balast onto a single tube.

Say you had 4 sockets, and 2 were overdriven 2x. You'd put new bulbs in the non-overdriven sockets and the old ones would rotate to the overdriven sockets, which will burn up their remaining lifespan faster but you will still get good light intensity out of them.

close.. if you have four socket and you overdrive 1 tube you only have two more sockets left..
a good idea would be to either overdrive both or 1 overdrive ( old tube ) and two more new non overdrive tubes, replace the overdrivin tube by moving a non overdriven tube to the overdrivin socket and the new tube to the non overdriven socket..

on the krib website, is a writeup about overdriving tubes and there life span.. they say, a tube doesnt only last 12 months, but for 100% power your lucky if that last more than 4 months..

so after 12 months the power droped to 60% overdriving the tube 2x you'll get 80% power overdriving them 4x gives you 120% power back.. so now you could make you tubes last twice as long by overdrivein you older tubes..

 

[Waterloo Kid]

OK so I can't overdrive a bulb just by placing a lower rated tube into a higher rated fixing. What would happen if I did that? Would I just blow the tube or fixing? The reason I'm asking is that I have just bought a second hand twin 54W fitting off ebay and I want to test the thing as soon as I get it. Problem is I've only got 39W tubes so I was going to try the unit out with these. Am I going to create a very short yet spectacular light show?

WK

 

[Dubby]

you cant overdrive any tube by driving a 39w tube with a 54w balast....

nor can you overdrive any tube with a magnetic balast

You overdrive a tube by dubbling up the connectors of a electronic balast.. Most electronic balast can drive 2 or 4 tubes.. so you connect both the connectors of the 2 tube balast onto a single tube.. or all four connectors onto 4 tubes balast onto 2 tubes.. or all four connector of a 4 tube balast onto a single tube.

I'm a bit confused. Wouldnt that be the same as providing more ballast rating per tube. Therefore if I connect a 39W tube to a 54W electronic ballast it should be overdriven?

 

[Waterloo Kid]

That's what I thought.

 

[Silly me]

I'm a bit confused. Wouldnt that be the same as providing more ballast rating per tube. Therefore if I connect a 39W tube to a 54W electronic ballast it should be overdriven?

no........

but the tube should run but at no means brighter. and you might notice the edge of the tube get darker or start turning black.

it because it will push to much power through the tube at startup.

there is a lot of info on the net about overdriving. readup about it a bit, before you overdrive your tubes.

 

[Silly me]

http/www.gardenbanter.co.uk/archive2/ind...g-NO-tubes.html

I took the plunge and decided to try an overdriven hood. I have
35-gallon tall hex, and the All-Glass light fixture contains a single
puny F15T8. Given the depth of the tank, this is hardly sufficient for
plants.

By gutting the original fixture, I was able to fit in two F15T8s. This
is largely because the original design needed a fair amount of room
for the internally-mounted ballast. I switched to an external ballast,
which was necessary anyway because of the larger size of electronic
ballasts.

I mistakenly thought that I could overdrive the F15T8s by just hooking
them to a ballast designed for two F32T8s. Wrong! At least with the GE
ballast available at Home Depot, the ballast somehow compensates for
the tube type. This ballast is actually rated to run anything from
F32T8s down to F17T8s, all at a ballast factor less than 1, and when
hooked to F15T8s provided only normal light output.

So I returned the 2xF32T8 ballast in favor of a 4xF32T8 ballast, and
tied a pair of outputs to each bulb. Wow! This really produces a
noticeably brighter light. I wish I had some way to quantify the
difference, but I don't have any of the appropriate tools to do so.

I ran it for several hours yesterday with no signs of overheating. In
fact, the fixture doesn't seem noticeably warmer than it was back when
it contained the internal magnetic ballast.

I pretty excited now to see how well plants will actually do with this
setup. I'm planning on using a combination of tall plants (like
Limnophila sessiliflora) that can get closer to the lights, and
shade-tolerant foreground plants like Anubias. I can't set up the
aquarium until next month due to the hallway being painted, but I'll
keep you all posted.

 

[Silly me]

More info at

http/www.plantedtank.net/odno.html

http/www.gwapa.org/articles/odno.asp

 

[Yenko]

Silly me, sorry for the misunderstanding, but by four sockets I meant four places to put bulbs, not four actual endcaps. I just thought saying "eight endcaps" would be wierder.

 

[Silly me]

Yenko, I think you understand the overdrive idea, I'm more worried about Waterloo Kid and Dubby, that might misanderstand the theory and overpower a tube rather than overdrive the tube..

 

[Waterloo Kid]

Electricity was never my strong point, I design bridges not electrical things. I can't be hassled with all this overdrive stuff, I'll just go out and buy some 54W tubes. Easy!

WK

 

[Dubby]

I think I understand The starting current has to be just enough to power up the tube(s) but the running power has to be higher (hence overdrive). So connecting two or more ballasts which have same tube rating (hence same starting current) will achieve this.

Whereas if we use a ballast with a higher rating then the starting current would be higher and may burn out the tube?

Have I got it right?

 

[Silly me]

Yes, thats 100% right dubby