pull cord dimmer switch

[HappyHippyDad]

I mentioned to a customer that there was such a thing as a pull cord dimmer switch, he bought one! I fitted it today, it didn't work!

There a couple of things confusing me, firstly I am getting 230v at the switch on both the 'IN' and 'Load' when the switch is both on and off. Secondly there is 230v going to the light but it doesn't work. It is a dimmable bulb, but even if it wasn't it would still come on a flicker. Have to admit I haven't checked the wattage, might be less than 50 and the dimmer cord states 50-250w, would this cause it to just not work?

Its more the 230v at the switch when on and off thats got me? It has to be a faulty switch, but seems unlikely, brand new and a switch is a fairly simple mechanism.

Will be going back on thursday to try with a normal switch.

Any suggestions would be much appreciated..... Diagram below of the junction box. All earthed just not drawn in.

 

[telectrix]

looking at your diagram, it might just be that the switch needs a neutral???

 

[tazz]

From your diagram, does the pull cord switch require a nuatral...???

 

[Octopus]

TLC product TL PCD51

TL PCD51

Fitted a couple but don't remember a neutral being involved!

This one needs a minimum of 50 watts!

 

[HappyHippyDad]

looking at your diagram, it might just be that the switch needs a neutral???

The leaflet with it clearly says :"The neutral terminals are provided for convenience of connection, a neutral connection is not required for operation of the switch", should have put that before, sorry.

 

[tazz]

Voltage is not the issue with dimmers, they actually chop the wave form, Can only suggest 1. Load in and out are wrong way round 2. not suitable for low voltage lighting or low wattage. 3 finally the unit is faulty, sorry cant be more help

 

[ferg]

change the lamp for a 100w if it works.....

 

[tazz]

change the lamp for a 100w if it works.....

Good idea...and simple...will eliminate one caurse

 

[HappyHippyDad]

Voltage is not the issue with dimmers, they actually chop the wave form, Can only suggest 1. Load in and out are wrong way round 2. not suitable for low voltage lighting or low wattage. 3 finally the unit is faulty, sorry cant be more help

So are you saying that it will always show 230v at both the 'IN' and 'Load'?

 

[tazz]

So are you saying that it will always show 230v at both the 'IN' and 'Load'?

Only whilst dimming, if in the off position then no voltage should be on the load terminal

 

[HappyHippyDad]

Only whilst dimming, if in the off position then no voltage should be on the load terminal

I'm changing the switch and not suggesting them again!

 

[Marvo]

Testing dimmer output is tricky and you'll get confusing results. Firstly as already stated the output waveform is 'chopped' or pulse width modulated if you prefer. Many standard electrical testers won't give you an accurate voltage or RMS reading of this type of waveform. Also there's an issue with phase angle so you'll often get a high voltage reading between the output of the dimmer and the permanent live as awell as obviously the neutral.

I'd use a 100watt incandescent lamp just to set the dimmer up with, this would get rid of a possible under-load problem until you know everything else is working. Also if something goes wrong it won't cost you a more expensive dimmable LED or CFL.

 

[eganelectrical]

Try linking out the live and switched live bypassing dimmer! Light work?

 

[Richard Burns]

Just check that your neutral connections at the light and JB are tight and fully connected, it may be that they are only connecting enough to register a no load voltage and then fail on loading.

However I would suspect a faulty switch as the first culprit.

 

[dave1064]

I have never even heard of a pull cord dimmer switch. I cant even imagi e how such a thing would work...

 

[Octopus]

I have never even heard of a pull cord dimmer switch. I cant even imagi e how such a thing would work...

Read post 4

 

[Marvo]

You could use a non-latching pullcord switch with any 4-wire or 3-wire dimmer module, you don't need to buy it as a complete assembly.

 

[HappyHippyDad]

All working fine... But I would love to understand whats going on with the voltage.!!

When the lightbulb is in place everything is as it should be.. i.e 230v at P/L in the switch and 2v at S/L (with switch off), however if I remove the bulb I then get 230V at the S/L with the switch on or off??

What is going on?

 

[HandySparks]

All working fine... But I would love to understand whats going on with the voltage.!!

When the lightbulb is in place everything is as it should be.. i.e 230v at P/L in the switch and 2v at S/L (with switch off), however if I remove the bulb I then get 230V at the S/L with the switch on or off??

What is going on?

What's going on is that it's not a conventional switch with contacts that open when off, it's an electronic device with a semiconductor as the 'switch'. Also, as it doesn't use a neutral, it uses the load as a return path for the supply to the internal workings, so with an open circuit output you will, indeed, measure 230V on the output.