flickering CFL lamps

[oldtimer]

Guys
Got a call from a customer saying his energy saving lights are flickering when switched off he lives in a small hamlet outside of Edinburgh so me thinks there will be an overhead line in this somewhere.

Now I have searched the forum and found flickering everything ie MR16,GU10 so I reckon there is an explanation for this. I would appreciate any guidance here as I dont want to trail out to tell him the obvious.

Ta very much

 

[grantr37]

there's a few reasons.......sometimes its overhead power lines (up to about 60m away depending on voltage, you know, like 127kv or 450kv) lines......nearby Railway 15Hz 25Kv traction current lines will do it on a damp night, but you would have to have a railway line just over the back fence for that, I have seen railway lines 4m from a back door before...
A lot of new CFL lamps now have a miniature electronic circuit and a rechargeable battery built into the base internally inside the actual Bulb/lamp, this is to make them start more quickly instead of warming up (like the Sylvania and Osram fast start type) what this does is it strikes the gas about once every 15 seconds and you see a little blue flash with brightness equivalent to a night light glow, in a really dark room this is very noticeable....this is to keep the gas inside the tube warm so that the light comes on to full brightness right away when switched on and can go on for a week or more after you turn off the light, if you leave one of those out of a fitting even just on the table you will see it blink for a week or so,until the internal battery goes flat...it recharges quickly again as soon as you switch the light back on....

there are also some new fittings with added circuitry to do this outwith the Bulb/lamp such as those accepting D Type lamps and also on those with miniature CFL lamps like the new desk lamps that use them....


I think if you take one of the lamps out of its holder it will have "Sylvania fast start" printed on the side of it.....those are the most common ones that do the blinking, followed recently by Osram......the Sylvania ones have been on the go since 2003....

 

[grantr37]

so you just need to change to a standard lamp/bulb(slow warm up CFL) if it bothers him, a lot of people think somethings wrong with the wiring when they see that for the first time....they don't print anything on the box/wrapper to tell average joe punter that the lamp blinks now and then to keep the tube "charged up" ready to come on full brightness.....
The normal CFL will take 30 seconds to come up to full brightness, buying Osram or other good quality as opposed to supermarket tat ones will mean a nicer light output (better spectrum like warm white)

 

[Noddy67]

Another suggestion: I had this on two-way switch connection with both LED and Fluorescent and I've heard others with the same problem on landings too (again where two way lights are used).

assuming the other regular (IR/continuity) tests were OK - and it's not an overhead issue that was mentioned here, it could be the circuit.

With long strappers there's enough induction going when off, to just flash those lights on every 7-15 seconds.

If that's the case you may need to fit a big resistor (snubber) in parallel with a lamp. If this sounds possible PM me and I'll dig out the part number from Maplin.

 

[needasparks]

Only time i've seen it was when they had one of the light switches on that circuit with the same line with a neon indicator, it can only be part of the wave being discharged which normally points to this. My case was an mk easyfind switch that lights up in the dark when off which left a return path for the cfl to flicker.

 

[oldtimer]

Thanks guys I thought this was the problem as I have read this a few times plus I told him it was a side affect of some of these lamps/bulbs or in other words nothing to bother about. He is emailing me later so thanks again.

 

[grantr37]

if he googles Sylvania fast start he will see the bulbs that you are on about when he asks....

 

[Taylortwocities]

If that's the case you may need to fit a big resistor (snubber) in parallel with a lamp..

Do NOT put a big resistor across the lamp. Have you thought about the heat dissipation?
You need a resistor and capacitor in series.

I've used these a few times....Buy RC Network Capacitors PMR209 PCB mount,0.47uF 100R 250Vac Evox-Rifa PMR209ME6470M100 online from RS for next day delivery.

 

[Noddy67]

Do NOT put a big resistor across the lamp. Have you thought about the heat dissipation?
You need a resistor and capacitor in series.

I've used these a few times....Buy RC Network Capacitors PMR209 PCB mount,0.47uF 100R 250Vac Evox-Rifa PMR209ME6470M100 online from RS for next day delivery.

and that's why I put 'snubber' in brackets as i believe this is what it is - and why I suggested a PM to dig out the exact details of the right product.

 

[Guest123]

Contact suppressor from maplin......

Contact Suppressor : Suppression : Maplin Electronics

 

[Taylortwocities]

Contact suppressor from maplin......

Contact Suppressor : Suppression : Maplin Electronics

Correct!

It's not a "big resistor"

Just stick a 100 ohm resistor across a 230v supply and see what happens. It's fun.

 

[grantr37]

anybody else been asked about lamps blinking after switched off?? ?? ? :star:

 

[oldtimer]

The guy who contacted me has not got back in touch but this post has answered my question

 

[Taylortwocities]

anybody else been asked about lamps blinking after switched off?? ?? ? :star:

Oh Yus