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Monday
Sep222014

Upgrade a Circline fluorescent lamp

While sitting at my desk I noticed a humming sound from the floorboards underneath my chair: it was the circular fluorescent light in the room below. The ballast unit in the ceiling light was buzzing and this could be heard downstairs as well as in the room above. I also had the nagging problem of the fluorescent light strobing several times, with several seconds of darkness before finally starting up. This had become a nuisance over the years, so much so that people would stumble around in the dark, which had caused at least one injury accident.

Upgrading the lamp is one answer but sometimes it’s not feasible or practical just to replace light fittings with modern halogen downlighters or LED bulbs, and if anything it can be a costly and wasteful exercise especially if it’s just in a utility room or cellar. I found circular fluorescent lamp fixtures are all but obsolete now, as everyone is switching to downlighters. Instead of raving around making big holes in the ceiling and trying to run wires everywhere, there is also the likely cost and payback time for an upgrade. As a long term proposition, LED bulbs or maybe CFLs are the way to go, and (thanks to the EU) halogen bulbs themselves are already being phased out. Until then I wanted to get a bit more life out of the circular light fitting, and as long as I can get new tubes I’m happy to do that.

Fluorescent tube apart, instead of struggling with old 1960’s tech, it’s straightforward to give a Circline circular light a new lease of life by upgrading the old-fashioned, noisy electrical gear with an electronic unit instead. They are cheap enough, very small and lightweight in comparison with a traditional ballast, and are rated up to 40W maximum (hence the 0.19 amps rating). So a 40W-rated electronic unit will be fine for my 32W tube. The other key benefit is that electronic ballasts are instant-on, with no flashing or buzzing, although you might have to accept a slightly lower light output (say 10% reduction).

DIY Instructions to upgrade a Circline circular fluorescent light

Any DIYer can install an electronic ballast and upgrade a typical 32W or 40W Circline circular fluorescent light unit. My own light unit had two wall switches and was an Italian-made lamp marketed by Ring in the UK, probably 15 years+ old and it’s likely that the wiring for yours will be no more complicated than mine, and possibly simpler.

Original Circline lamp fixture and wiring [click to see]

First, it’s essential to switch off the lighting circuit at the fusebox and double check that everything is isolated before doing (or touching) anything: ideally use a contactless mains detector on the light’s wiring if you have one. That’s because some light circuitry wiring can be permanently live. Switching off the light switch(es) isn’t good enough. So make sure you either pull the fuse or switch off the circuit breaker and double check that it’s all turned off, using a tester if possible. I found neon screwdriver mains checkers tripped the circuit breakers due to leakage current, but the contactless C&K type with LED and beeper that I used was fine.

Testing to ensure the mains is switched off [click to see]It’s a good idea to photograph the lamp’s wiring using a smartphone for reference. With the mains isolated, look closely at the existing wiring and identify the mains Live (L), Neutral (N) and Earth (E) feeds that probably go to a screw terminal block. Multiple wires might go into one terminal and several live wires might be joined together (part of the ring mains wiring) which should not be altered.

Old fluorescent light wiring [click to see]Live wires going into the terminal block might be brown or more probably black with a red sleeve. This live wire must not be confused with an ordinary black (Neutral) wire.

  • As shown in my photo, there was a fault with my existing wiring: the red sleeve was missing, but the black wire is LIVE INPUT. I added a red sleeve straight away.

Unplug the fluorescent tube by pulling off the 4-pin plug and put the tube aside for now. You can then unscrew the terminal block screws to loosen the mains L, N, E input wires. As the existing push-fit/ screw terminal block could not be re-used I fitted a new one. Then re-wire L, N and E inputs to the new block.

The terminal block might need unscrewing from the metal baseplate. Also remove the starter (the small cylinder with two wires). It rotates and pulls off, then prise the base off the light unit. The old ballast unit can then be unscrewed (it’s heavy) and the whole assembly should come away.

The new electronic ballast is much smaller and lighter and can be fitted to the metal base using one screw from the old ballast (do not overtighten). The unit’s Live (red) and Neutral (white) wires can be connected to the L & N feeds of the (new) screw terminal block.

New electronic ballast wired, with new terminal block and earth wire [click to see]It is essential that the lamp remains properly earthed after the upgrade. Earth wires are usually bare copper, and should be sleeved with green & yellow tubing. I clamped a solid, sleeved earth wire under the mounting screw of the old terminal block screwed onto the light fitting’s metal base, and connected the wire to the Earth terminal of the new screw terminal block. Thus the light fitting’s metal base was earthed properly.

Refit the fluorescent tube and connect up the new electronic inverter. Shuffle the tube around if the connector doesn’t quite reach. Fit the lamp diffuser and switch on the mains – you’ll find the lamp will now light instantly with none of the fuss and bother of the old unit.

Tube running with new electronic ballast [click to see]I intend to do the same with a kitchen lamp too. Here’s a suitable electronic ballast, and as they’re so cheap maybe keep one for spare. A good quality C&K non-contact tester (T2272A) is also shown. It has red-green LED and audible buzzer indication of live wires, without needing to touch them directly.

 

Monday
May122014

What is a kiloWatt Hour?

With the emphasis on reducing energy bills – and making them easier to understand – you might have come across the term “Kilowatt Hour” or kWh when talking about the cost of electricity or gas. A new term 'Tariff Comparison Rate' or TCR is also appearing. Understanding what these terms mean is very straightforward.

Click to read more ...

Thursday
Feb132014

Homebase round mirror inverter repair (Part 2)

To recap, having swapped the light tube only to find it still wouldn’t light, I discovered that the original electronic ballasts are no longer made, not even by Landlite. It's this that gives the light its instant-on feature without any flickering, but it seems the EB-56 ballast is prone to failure and a few people have had problems with them.

Rewiring the whole lot using a traditional ballast and starter isn't trivial. The only other option is to try a Chinese-made 40W circular fluorescent tube inverter instead, and the very thing was being sold on ebay (if you import from Hong Kong) as well as on Amazon.  Otherwise, consider upgrading to a more modern and reliable LED bathroom mirror such as these LED Bathroom Mirrors on Amazon.

The Chinese inverters aren't CE-marked (not that CE marks count for much on some Chinese imports anyway) but having scoured the planet searching for a new inverter, this was all that's available. They're £6 each and Amazon delivered a couple in 48 hours. (I got one for spare.)

Comparing Landlite EB-56 inverter (click to enlarge)As they're not as big or heavy as the original Landlite EB-56, they’ll fit inside the mirror without a problem.  Read on...

DIY instructions to repair a faulty Homebase mirror lamp inverter

Switch off the mains at the fusebox, or switch off the relevant ring-mains or (in my case) lighting circuit breaker. If the mirror’s above a sink, put the plug in the plughole in case any screws fall in.

Remove the four screws holding the glass on the metal base, and gently pull off the mirror.
  Mirror removed, revealing the tube and inverter (click to enlarge)

Landlite EB-56 inverter and terminal block (click to enlarge)Unscrew the terminal block cover, loosen the cable cord grip screws and disconnect the Live (brown) and Neutral (blue) wires going to the old inverter. As the Live goes to the pull-switch, that must be unscrewed  to get to the screw terminal, while Neutral goes to the main terminal block.

Terminal block and pull-switch housing (click to enlarge)Also disconnect the Earth (green/ yellow) wire that goes to the old inverter. Leave the light’s main earth wire in place, safely connecting the light's metal chassis to the Earth terminal block.

Remove the old inverter's Earth, Neutral and Live wires. The pull-switch has to be unscrewed to access the Live terminal (click to enlarge)

Terminal block minus the old inverter's wiring (click to enlarge)

Note the replacement inverter needs no Earth wire; that’s OK as the old Landlite inverter simply had  extra filter circuitry connecting to Earth.

Pull off the fluorescent tube’s connector plug. Remove the two mounting screws and the old inverter will come away.

 The old inverter removed. The lamp's earth wire remains connected as shown (click to enlarge)

The new inverter is smaller and doesn’t fit the two existing mounting holes. Typical. As it only weighs a third of the original one, I chose to mount it using the original screw on the right handside only. The other option is to drill and tap a new hole in the base for the inverter’s lefthand mounting tab, which I thought was over-elaborate as the new inverter is fairly lightweight and it isn't going anywhere.

 The new inverter in situ, held down with one screw. Unused screwhole circled in red. (click to enlarge)

Connect the new inverter’s Live (red) wire to the pull-switch, feeding it through the cable grommet and cable grip in the terminal block. Connect the Neutral (white) directly to the Neutral screw terminal block. Ensure none of the wires is trapped anywhere when the pull-switch is screwed back down, and that the switch operates smoothly without the cord jamming. Again, double check the light's earth wire is still connected properly to the main terminal block.

 New inverter in place and the tube is reconnected. Note the earth wire. (click to enlarge)

The fluoresecent tube can be reconnected, moving it around on its clips if necessary so the inverter’s connector lead can reach it. Finally, replace the terminal block cover. You can now turn on the mains and test the lamp.

 After re-assembling the terminal cover, turn on at the mains and test (click to enlarge)

Finally, check the rubber seal going around the edge is located properly to protect against moisture, and then the mirror can be screwed back into place. Job done!

A £6 inverter isn't quite as good as the original but it's good enough and has given the light a new lease of life.

  • Information was correct at time of writing,  13th Feb. 2014
  • Also see my piece on upgrading a 32W Circline ring fluorescent ceiling light here
  • The unit's mains wires (red and white) don't always tally with the label. You might want to read my item about this discrepancy on the JL-EB40Y here.

 

Tuesday
Feb112014

Homebase circular bathroom mirror woes...

Homebase Bathroom Mirror with circular fluorescent tubeI’ve a Homebase illuminated mirror in the bathroom, lit from inside by a circular 40W fluorescent tube. Unlike most fluorescent lamps, thanks to its electronic ballast this Homebase mirror lamp starts instantly with none of the annoying flashing associated with traditional lamps.

I’ve learned quite a bit this week about these lighting fixtures, starting from the time when the thing suddenly refused to light up: on switching on it glowed feebly and then went out. It had to be the tube, or so I thought, so the search was on for a replacement fluorescent tube. I would eventually find that this mirror has a ‘reputation’.

Our kitchen uses the same size 40W circular lamp (with traditional-style starter). Recently that failed as well, and I had to hunt around for a replacement. This was hard going as none of the DIY sheds stocked any (Homebase was the safest bet, but were out of stock yet again), but a local lighting store supplied a new tube which was soon installed and running in the kitchen.

I noticed how the kitchen seemed ‘warmer’ and less stark than before, which was due to the different colour temperature of the new tube. I dug deeper into this aspect and that found these tubes have different colour specs. but it was entirely pot-luck which one your local store might have in stock: to them it’s just a 40W circular white fluorescent tube.  So you could adopt either a brutal Xenon-like pallor or a healthier golden glow depending on what colour temperature the tube produced. Supermarket display cabinets mess around with fluorescent tubes a lot, in order to make butcher’s meat, for example, look a healthier shade of red.

Colour Temperatures

After measuring the mirror’s tube as 40cm across, I headed over to Wikipedia, where at http://en.wikipedia.org/wiki/Fluorescent_lamp_formats it’s mentioned that this unusual circular tube (Circline) is designated a ‘T9’ and has a four-pin connector called a G10q quadpin contact.

Colour temperatures are also spelled out: it’s stated this is a 3-digit code starting with 8 followed by 2 digits for the colour temperature, which is printed on the tube. As photographers will know, colour temperature is measured in °Kelvin with daylight being about 6,500°K. A higher colour temperature (eg 8,000°K) is a purer, starker white and a lower rating (say 3,000°K) is warmer and more golden-looking.

Hence the next two digits (830 or 865 for example) in the colour code refer to the colour temperature. Another factor called the Colour Rendering Index (CRI) describes how accurately the lamp reproduces colours across the board, as they can have spikes in the colour spectrum that gives strange results: that’s why my Honda is a very weird colour when seen at night under filling station lights.

Sylvania 40W Circline tube - note the colour rating printed on the box (click to enlarge)The colour rating is also printed on the tube (click to enlarge)The most popular colours for a T9 Circular “Triphosphor” fluorescent tube are:

830 – Warm white - e.g. kitchen, a slightly warmer glow
835 – White
840 – Cool white
865 – Daylight - bathroom mirror, a stark brilliant white

Then it’s onto ebay in search of some new tubes.   Brands to look for include Crompton, Eveready and Sylvania. I wanted an 865 daylight tube for the mirror and (while I’m at it) a spare 830 for the kitchen light.  The only supplier I could find on ebay wanted £16 carriage (ouch), and when I asked for a quote they simply said that I should pay the full amount and they’d refund whatever the difference would be. Not likely...

Crompton 40W Circline tube with colour temperature arrowed (click to enlarge)

The need for different colour temperatures became a bugbear, but eventually I found a supplier The Lightbulb Company   www.thelightbulb.co.uk  offering exactly what I needed. Suffice it to say the order was placed online on a Friday and they arrived safely first thing Monday morning.

And then the bad news!

The new fluorescent tube wouldn’t light either! So the problem had to be the electronic starter found in the Homebase mirror. Turns out quite a few people have had problems with the Landlite EB-56 electronic ballast failing. More of a problem has been trying to find a spare: there aren’t any, not even on the Hungarian manufacturer’s Landlite website http://www.bolt.landlite.hu/en/  where there is no such beast as a ballast for a circular fluorescent G10q with four pin plug.

In fact there were no electronic ballasts anywhere to be found at all. I guess they are a casualty of the move towards halogen and LED lighting. The last resort is a Chinese-made one for 40W circular fluorescent tubes listed on Amazon which (interestingly) several buyers have used for their Homebase mirror. They’re £6 each so I’ve bought two just in case.

See Part Two for full details of installing a new electronic ballast in this type of mirror. I also upgraded a Circline circular fluoresecent lamp in a similar way, details here.

More links

http://en.wikipedia.org/wiki/Kelvin#Colour_temperature

http://en.wikipedia.org/wiki/Fluorescent_lamp#Color_temperature

http://en.wikipedia.org/wiki/Color_rendering_index

Friday
Jun152012

Credit reference files – use your Noddle

UK credit rating reports hold an awful lot of information about your financial affairs. You can now access this data for free using the free service outlined in this article.

Click to read more ...