Shorten Fluoro fitting for LED element

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pbolger

241 posts

Master Geek

#185712 2-Dec-2015 16:06

I've just bought a 2 foot LED fluorescent tube replacement (It comes with an "LED Starter") but only have a 4 foot fitting. By the looks of things it'd be very easy to shorten the fitting - take an end off and chop the steel to the new length.

But, there's an electronic ballast included in the fitting. Does anyone know if this differs depending on the length of the tube? Would I endanger my tube using the ballast from a longer tube fitting?

sep11guy

660 posts

Ultimate Geek
Inactive user

#1439351 2-Dec-2015 16:16

the 1200mm is catered to power 36w/ 28w / 54w

and 600mm is catered to power 18w/14w/24w

so there is quite a bit of difference here :)

richms

28187 posts

Uber Geek

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#1439354 2-Dec-2015 16:21

Led retrofits only work on magnetic ballasts.

Richard rich.ms

sep11guy

660 posts

Ultimate Geek
Inactive user

#1439357 2-Dec-2015 16:26

there is also another type though :

Type B: LED tube has an Internal Driver and is Wired to Main Voltage Bypassing the Existing Fluorescent Ballast (aka Bypass, Internal Driver)

How it Works

With Type B LED Tubes, the ballasts are removed from the fixture or bypassed, and the sockets are wired directly to the line voltage. Typically only one socket end has the line voltage and the other end is there to hold the lamp in place. Many fluorescent fixtures have shunted sockets so often times you will need to replace the line voltage socket to a non-shunted socket.

richms

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#1439403 2-Dec-2015 17:03

If it requires modification to the fitting it is not a retrofit lamp. I was not able to find out what the legal situation with those is, as anything modified fitting wise creates a saftey issue if someone sticks a fluro tube back into it. Best I could get was a "I don't think that's a good idea".

The losses from the ballast being in series with the power to a switching power supply are minimal, and leaving that there means the fitting is still safe if it gets re-lamped with a fluro tube. If the fuse starter is still in place, it will just run the heaters and not light, if it is also replaced with a switch starter then the tube will work.

The only ones legal here are single end power with the other end shorted and a fuse to replace the starter, many cheapies off ebay/aliexpress are live at one end and neutral at the other and require the starter be removed. Means that if you touch one end while putting the other in, you get a shock which is non-ideal. If you fit a starter and put the tube in then sparks and bang will happen.

Richard rich.ms

pbolger

241 posts

Master Geek

#1440656 4-Dec-2015 17:28

Thanks all.
My fitting is definitely an electronic ballast version, so no use for this either way. The actual element is a Verbatim 64353.