Converting from electromagnetic to electronic ballast in fluorescent light

[Mike Clarke]

I'm considering replacing the ballast with an electronic one in a 6 ft

70W fitting but wondering what sort of interconnecting wire to use if the lengths of the existing wiring isn't sufficient. I appreciate that the wire needs heat resistant insulation when running beside the magnetic ballast but would normal PVC singles be OK with an electronic ballast?

[Bob Minchin]

You should not need high temp wire as the whole object of an EB is better efficiency. But if you want you could buy a couple of metres of 3183TQ 0.75mm2 and strip out the cores.

[tabbypurr]

anything mains rated.

NT

[Alan]

I wouldnt bother, just buy a LED tube and modify the internal wiring as necessary. They are really cheap now.

[Brian Gaff]

To be honest the other week when cleaning out the muck from an old Thorne fitting it seems to me that the wiring was nothing special at all. If the ballast gets hot then its not working properly. Of course this is just common sense talking here, and we all know that standards are written with a completely different ethos! Brian

[Mike Clarke]

That's what I'd originally considered but a 6ft LED only gives 2600 lumens compared to 6200 for a fluo.

But I'm having second thoughts on changing the ballast anyway. A new Thorn 6ft PopPack batten with HF ballast and tube costs a couple of quid less than an electronic ballast and tube - and I need a new tube anyway.

[Steve Walker]

That's a large difference and staying with fluorescent seems sensible. Although a quick search returns 6ft LEDs with over 3000 lumens and a more in-depth search may find better still.

Also remember that LEDs don't have to produce as many lumens as fluorescents for the same effect - because LEDs usually produce over

180°, while fluorescents produce over 360° and only a proportion of the upwards lighting gets reflected back from the fitting and the ceiling, with some being absorbed.

I must admit that I am interested in replacing some 4ft flurescents with LEDs, but because of these differences, I don't know what ratio of lumens output will give the same level of lighting.

Probably the best option.

SteveW

[Dave Plowman (News)]

But having a nice dim LED gives you that warm 'I'm saving the planet' feeling. Also decent tri-phosphor tubes can give far better light quality than many LEDs. Which can matter in a work area.

Often the case. Have you looked on Ebay for best value ballasts?

[Mike Clarke]

Thanks for reminding me about Ebay which I hadn't considered at that stage. On searching Ebay I found a Tridonic electronic ballast for my

70W tube at only £9.40 delivered which sounded too good to be true considering the best I'd found online for the same ballast was £23.40 plus delivery. It was a small scale Ebay seller but reviews were all 100% positive and included feedback on a number of similar devices so it looked like worth taking a gamble.

The ballast arrived yesterday, I ripped out the guts of the old fitting and installed the ballast using cores pulled out of some 1.0mm T&E which fitted fine in the Wago type terminals. The light is now up and running fine, and according to my cheapo power meter using considerably less power now that I've ditched the choke.

The spec sheet for the ballast

stated that the leads for the tube ends should have a capacitance of less than 100pF for one pair and 200pF for the other (corresponding to max lengths of 1 metre and 2 metres). This is no problem, they were well within the limits but I'm curious why an electronic ballast should have these different requirements - it's not as though there's any difference between the filaments at each end of the tube. Do any electronics experts here know why this is?

[Dave Plowman (News)]

I'd guess because of the high frequencies involved?