wiring fluorescent tubes

[sm_jamieson]

I will be making up some fluorescent lights on top of the kitchen cabinets. I am getting dimmable high frequency ballasts from RS, and the dimming control is sorted out. So the question is, what is the minimal wiring job I can do to connect the ballasts to the tubes that complies regs etc. ? If I just get some end caps and some means of supporting the tube (those metal spring clips ?), and wire them to the ballasts (high-voltage cable ?), is that sufficient ? I vaguely remember hearing something about needing an earth plane parallel to the tube (which would usually be supplied by the metal fitting containing the ballast), but I have no idea why this would be required. If it is, could I simply have some earthed foil running alongside the tube ? Or perhaps earthing the metal tube support clips (say 3 along the length) would do ... Simon.

[Mike Tomlinson]

In article , sm_jamieson writes

It's to improve striking of the tube. You may very well find you don't need it, especially with electronic ballasts.

[meow2222]

am getting dimmable high frequency ballasts from RS, and the dimming control is sorted out.

ballasts to the tubes that complies regs etc. ?

spring clips ?), and wire them to the ballasts (high-voltage cable ?), is that sufficient ?

yes, with mains flex

the tube (which would usually be supplied by the metal fitting containing the ballast), but I have no idea why this would be required.

its not normally. There are historic ballasts that needed it. If your modern one also does, which is unlikely, the destructions will say so, and probably earthing the tool clips would suffice.

NT

[sm_jamieson]

I am getting dimmable high frequency ballasts from RS, and the dimming control is sorted out.

ballasts to the tubes that complies regs etc. ?

metal spring clips ?), and wire them to the ballasts (high-voltage cable ?), is that sufficient ?

to the tube (which would usually be supplied by the metal fitting containing the ballast), but I have no idea why this would be required.

one also does, which is unlikely, the destructions will say so, and probably earthing the tool clips would suffice.

I probably want a reflector under it, and if so its probably aluminium which might as well be earthed. Simon.

[Dave Plowman (News)]

No need for an earthing strip with high frequency ballasts.

You can buy cables with the tube plug moulded on - and the cable is just a very basic twin extruded. I suppose you could sleeve that if you're worried.

The Osram dimming ballasts I have use just a plain pot as the dimmer, carrying low volt DC.

[sm_jamieson]

I was going to get the philips ones that use a pot between two terminals. They are "1-10V control" but one terminal has a 10V reference on it. I have control cable (i.e. mains rated insulation) running to the location for the pot connection. Where did you get the Osram ones from, since I had only found the Philips ones ? It's always good to have another option.

I might make a reflector out of silver foil.

Simon.

[sm_jamieson]

For some reason, none of the documentation for these units states there is 10V on one of the terminals, nor explains what the - and + terminals mean, and the impression given is that 1-10V relative to earth has to be supplied from elsewhere. Only only found out a plain pot works by the link to a "dimmer" on the RS site. I bought a dimmer and looked at it and it was just a plain pot (with trimmer for minimum setting). I understand it is a European standard interface so I assume this is documented somewhere.

Now I have to furtle a plain pot onto the back of a brushed steel mains dimmer so it looks OK instead of being white plastic.

Simon.

[sm_jamieson]

on one of the terminals, nor explains what the - and + terminals mean, and the impression given is that 1-10V relative to earth has to be supplied from elsewhere.

site. I bought a dimmer and looked at it and it was just a plain pot (with trimmer for minimum setting).

documented somewhere.

so it looks OK instead of being white plastic.

I remember now, I found this

(1-10V dimmer with push switch) and we decided it could not in fact be wired up to regs, since you cannot combine mains voltage and extra low voltage in the same back box. So I have wired up a switch and separate dimmer.

Simon.

[Dave Plowman (News)]

I don't see why you can't have mains and low volts in the same box - if you know what you're doing. Sounds to me like a 'shotgun' regulation.

[sm_jamieson]

In the end I think I did not pursue this, since I decided it would be useful to have the dimmer and switch separate to reduce the effect of household "twiddlers" ;-) Simon.

[meow2222]

A reflector needs to be cleanable

NT

[sm_jamieson]

I suppose you could just replace the foil... There are reflectors availabl on the internet, commonly used for aquariums. But certainly an upward pointing open refector could collect a lot of dust. Simon.