Faulty switch?

[Jameswren]

I have some lights on a dimmer switch and they weren't very bright, even when the control was turned to maximum, so I replaced the switch.

It's worked all day then the fuse went. I turned off those lights, flipped the fuse back, and the rest of the lights on that ring work.

Have I fitted the wrong switch or is it faulty?

I think a transformer is also faulty because one lamp was out, I replaced the lamp but it still didn't work.

What should I do to get it all working?

 

[winston1]

I have some lights on a dimmer switch and they weren't very bright, even when the control was turned to maximum, so I replaced the switch.

It's worked all day then the fuse went. I turned off those lights, flipped the fuse back, and the rest of the lights on that ring work.

Have I fitted the wrong switch or is it faulty?

I think a transformer is also faulty because one lamp was out, I replaced the lamp but it still didn't work.

What should I do to get it all working?

For a start you cannot run a dimmer into a transformer. The chopped waveform will cause all sorts of nasty large back emf problems. So for a start put a conventional switch in and see what you get.

 

[Jameswren]

Perhaps I wasn't clear - the lamps run off transformers, the switch doesn't.

 

[winston1]

Perhaps I wasn't clear - the lamps run off transformers, the switch doesn't.

No, you were quite clear.

You cannot use a dimmer with transformer loads.

 

[Jameswren]

It's worked for 5 years with the same set-up.

Maybe my low tech knowledge is too low.

I have down lights connected to white boxes - I thought they were transformers.

I have the same set-up in 5 rooms with no issues (until today).

 

[Jameswren]

Untitled

• Jameswren
• 10 May 2014
• 1

 

[winston1]

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• Jameswren
• 10 May 2014
• 1

That picture looks like a (wrongly labelled) switch mode power supply rather than a transformer. Some switch mode supplies are dimmable, some are not. That one does not say dimmable on it.

 

[Jameswren]

Upside down but this side says "dimmable".....

Untitled

• Jameswren
• 10 May 2014
• 1

 

[winston1]

Back to the original problem. Disconnect the switch mode power supply (mains side) of the lamp that does not work because if it is faulty it could be damaging your switch. Then try a new switch.

 

[Jameswren]

Sorry, I really am low tech on these sorts of things! What's the "switch mode power supply"? Is it one of the wires going to the transformer? I assume not because wouldn't it be dodgy leaving a wire free?

If I get a "normal" flick switch is that ok to test things?

If it does work, does that suggest the transformer is causing the problem with the dimming?

 

[securespark]

You cannot use a dimmer with transformer loads.

Utter poppycock.

Of course you can. You just have to combine the right gear.

Disconnect the switch mode power supply (mains side) of the lamp that does not work because if it is faulty it could be damaging your switch. Then try a new switch.

There are several of them. It may not be immediately obvious which one is faulty - if there is a fault on them at all.

Why don't you ask relevant questions like:

"What is the total load on the dimmer?"

"What size is the dimmer?"

"Are all the units (be they "transformers" or SMPS's) dimmable?"

 

[Jameswren]

Before this deteriorates into a ruck - looks like you're suggesting the switch may not be up to the job.

I'm not at the property to check but tomorrow, will (should it be obvious on the switch what wattage it can handle?

As I said, it's worked fine for 5 years until recently when the lights were very dull regardless of how the switch was positioned. One of the lamps stopped working around the same time.

 

[333rocky333]

Theres more than one type of dimmer, yet externally they look alike, the transformer instructions usuallly state the type needed as the dimmer and transformers need to be compatible.

Though fitting the wrong dimmer shouldnt blow the fuse, more likely just dim eratically.

It may be best to try a more robust normal on/off switch till you get all the lights working rather than risk blowing your sensitive dimmer.

That one light could be causing the problems if the transformer is internally faulty, so may be worth concentrating there first, perhaps temporary removing

Try googling that transformer model and you may find its either trailing edge or leading edge and thats the dimmer you need.

Alternatively it will be on the dimmer you removed

Rather than be confused, in your situation transformer or smps or switched mode power supply all refer to the white box you show.

 

[securespark]

There are many different potential causes for your system fault.

From your description, it sounds like a fault occurred which blew the fuse.

This could easily have damaged the dimmer at the same time.

This is why the lights controlled by it no longer work, but the rest on the circuit do.

As Winston suggests, disconnect the suspect unit then replace the dimmer with a plate switch and see if that solves the issue.

If you decide to reinstate the dimmer, make sure it is up to the job of dimming both that type of unit and the lighting load.

 

[winston1]

You cannot use a dimmer with transformer loads.

Utter poppycock.

Of course you can. You just have to combine the right gear.

Disconnect the switch mode power supply (mains side) of the lamp that does not work because if it is faulty it could be damaging your switch. Then try a new switch.

There are several of them. It may not be immediately obvious which one is faulty - if there is a fault on them at all.

Why don't you ask relevant questions like:

"What is the total load on the dimmer?"

"What size is the dimmer?"

"Are all the units (be they "transformers" or SMPS's) dimmable?"

You cannot use a dimmer on a transformer as the chopped waveform will cause a large back emf. I do not write utter poppycock

Surely it would be obvious that the faulty one would be the one connecters to the light that does not work.

It has been established that the SMPTs are dimmable.