Workshop Lighting

Just read an interesting post on another forum. For those changing to 'Lower wattage' tubular LEDs , the practice of substituting the starter with a 'Dummy' is NOT going to cut your bills when using an original fitting, the Choke and capacitor still draw current.

It doesn't take too long to strip the guts out of a fitting and connect the mains to ONE end fitting, LED tubes are fed from only one end (normally clearly marked) so the wires on the 'dead' end can be chopped off, it's only there to support the tube.

'Twould appear , one tube supplier has had to modify their sales blurb Twice due to this 'Error'

Regards Ian.

Thanks for that info Ian, I'll be changing the 3 in my workshop some time this year.

Jim

That's how I wired mine, lots of info on the web as well...

I’m less than a mile from Andrew tomorrow morning, for breakfast. I would have called in on him, if I didn’t have an extra passenger. His barn lights were OK-ish when I was last there. It would be interesting to see the difference/improvement. Perhaps next time I a past….

While it is better to remove them, the losses in a the choke and power factor correction capacitor are pretty low when running a LED replacement "tube". If you doe remove them the fitting should be claerly labeled to that effect.
Better overall to just replace the whole thing with an LED fitting. I got some KBAT4 units from TLC and they are good.

On a connected note fluorescent lamps are effectively being banned by the EU from 1st of Feb 2024. They have removed the exemption from the mercury ban. Of course we in the UK are not in the EU any more so it won't affect us. No, wait, the UK has passed a law, almost identical to the EU one, removing the UK exemption effective 1st Feb 2024......

Edited By Robert Atkinson 2 on 19/05/2023 21:48:52

This was well timed, I'm just about to replace 2 of my tubes.

So to get this clear, do I just connect the mains to one end of the LED tube and just use the fitting at the other end to hold it up? Does it matter which end?

I recently replaced the lights in the old workshop. So at the time with the special on, it was nicer to replace the whole assembly with new batten lights with a very nice diffuser . It was so good, I changed the other 3 and the electrician added another switch, so I could have only 2 at a time going over the main work area. In hindsight, could have just installed 2 and got rid of the other 2 all together.

Neil

Wish I'd read Henry's post before writing mine, it answers it all

Sorry Duncan, thought I'd made it clear re the 'Live' end. When I converted the eldests' tubes in his workshop, the gubbins were stripped out and I made sure he knew about which way round the blubs had to be fitted. I had a twin 8ft fitting in my kitchen and was going to cut the batten holder down to suit the two 5ft replacement tubes, (Yorkshire cost saving trait) but capitulated and bought a new twin batten with the tubes. There are stickies on the ends of the unit 'Live' at one end and 'Dummy' at t'other.

Why do flies favour the 'Live' end to cr*p on???

Regards Ian.

You had, I was being thick. Greetings from a fellow Tyke (currently on missionary work in Cheshire)

Because it's hotter

NO they are NOT low. In my case (author of the thread in madd modder forum) a 24 watt tube was demostrated to draw 80 watt - actually MORE than the original tube. My findings were verified by TLC who are a very large electrical distributor, and all credit to them they provided two sparks for a day to remove the capacitors and wire out the chokes in my workshop. The capacitors were the major factor.

Anyone want any power factor correction cPcitors - I now have about 40 surplus

I'd refer you to the original article in mad madder as there is a lot of detail omitted in this reference.

Article titled 'Electricity getting very expensive in the workshop'

by the way

Thanks for that. My experience over the past few years is that LED lamps are expensive and don’t last very long so I shall pop out and get some spare tubes and starters. Given the amount of time my lamps are actually on this could save me some money.

I’ll have to order some more daylight fluorescents for the house as well.

About a year ago in our garage I fitted two LED tubes as replacements for the two 1500mm fluorescent lamps. One LED failed altogether within a couple of months, the second one started flashing on off, then only illuminated 50% until it failed, on the label attached to the LED it said, 15000 light hours, the shop replaced both FOC keep your receipts !. For the workshop, I bought 3 lengths of 30 X 30mm angle plastic and via the net a 5 metre length of self adhesive 12 volt DC LED. I stuck the LED to the angle and the angle to the roof, Its powered via a redundant computer power supply, I have a pull switch in the roof which controls the PSU input. The lighting system work well and I intend to extend the system in the autumn. Recently I fixed the driver for a friends LED outside light I was amazed how little there was in it, five components, ingenious, but it worked. John

The 36 LED fluorescent replacement tubes referred to in the madmodder thread have been installed for over a year now without a single failure. It was when I was considering buying a further 28 tubes for my welding shop that I decided to check that they were actually saving power before investing more cash - and they weren't !

Now that the capacitors and chokes have been eliminated and I've installed the extra 28 tubes - the power saving is approximately 2kW in both my main workshop and the welding shop when all the lights are on and the perceived lighting is actually better.

The Owl meter in that madmodder thread looks very similar to an old Efergy unit that I have and no longer use.

I discovered it misread inductive loads badly and claimed my kitchen hob was using 200W on standby,

Could a similar thing be happening with the ballasts/chokes in the tube fittings?

The "now" function on my (dreaded) smart meter appears much more reliable.

I called in on Andrew this morning to see his new lights ‘in the flesh’ (and for another enquiry I had from a forum member). The replies above seem to have arrived thick and fast from Andrew. I like his new lighting - both the low-level and high-level (not easily reached ones).🙂

I suspect the measurement too! Be good to see a circuit showing how the LED tube was connected relative to an unremoved LC ballast. Even if connected, it's difficult to imagine how a ballast could consume more power than a LED lamp. Maybe rewiring connected the ballast directly across L and N? Seems unlikely.

Maybe the answer lies in the nature of the ballast. It's an inductor and capacitor in series, not a resistor, and reactors do not behave like resistors when AC current passes through them. Where it not for the ohmic resistance in the copper coil, the inductor would be lossless, and the capacitor is near lossless too. Reactors work by charging and discharging efficiently, and as energy in is very nearly energy out, the loss in a well-made device is usually tiny. For example, power transformers are about 99% efficient.

I suspect the measurement. In the scientific sense power is the rate of doing work, energy transferred per second, and power is measured in Watts. In a DC system, Watts are simply volts times amps, because the two are always in phase. Not so in an AC circuit with inductors and capacitors. Being reactive these shift the phase of the voltage relative to the current, so simply multiplying AC Volts and Amps doesn't give Power. The unit being measured is a Volt-Amp, which is 'apparent power', not 'real power'. To convert Volt-Amps to Watts, it's necessary to correct the measurement for phase difference. The maths is more complicated.

The purpose of a ballast is to limit and stabilise the current flowing in a lit fluorescent tube, and they're unlikely to waste much power, certainly not nearly 60W per lamp. The acid test would be to measure the temperature of the ballast components, because they'd be cooking hot if they were really consuming 60W! As far as I can see that test, or smoke, isn't mentioned on madmodder, so my money is on Volt-Amp confusion.

Do sparkies cover inductive and capacitive weirdness? Electrical and Radio Engineers do up the ying-yang, but maybe this part of AC theory isn't useful to the chaps who do the hard work. Wiring up and installing is another skill set.

So, yes the ballast will waste some real power, but the amount should be tiny. I think the meter measured apparent power, VA, and the confusion is due not converting VA to Watts with the right maths.

Dave

Edited By SillyOldDuffer on 23/05/2023 18:00:03

I had thought I understood some of this but clearly I don't understand enough. Can anyone suggest what type of "wattmeter" I could get which would read "real "watts on AC mains circuits. I don't need an expensive professional standard thing just something to give me an idea of consumption.

Thanks

Rod