dimmer switch - quick question

howdydoody · 25 Feb 2008 at 17:25

Hi,

I was at my brothers last night and I noticed that one of the bulbs had gone on the front room light, its a 3 bulb artsy farty light. He left the lights on and started unscrewing the bulb, the glass came off in his hand leaving the metal bit inside. However, as the glass broke free there was a big flash and it tripped the mains board.

After fumbling around outside I managed to find the mains and switch the lights back on. He replaced the bulb but now the dimmer switch isn't working.

I have removed it from the wall and had a look at the backside of the dimmer however its just a big chunk of grey plastic. I am thinking that maybe the resistor has blown. Is it possible to replace or is it a case of buying a new one?

yipyipboo · 25 Feb 2008 at 17:37

probably safer and easier to buy new.

Carl · 25 Feb 2008 at 17:59

Have you checked that there is still power to the switch?

When a lamp blows there is a earth fault and the RCD has detected this and is doing it's job.

howdydoody · 25 Feb 2008 at 18:01

I should have said that the dimmer switch itself does turn the lights on and off when it is pressed in, however when you turn it to dim the lights nothing happens.

Carl · 25 Feb 2008 at 18:03

howdydoody said:
I should have said that the dimmer switch itself does turn the lights on and off when it is pressed in, however when you turn it to dim the lights nothing happens.

Never had that problem but i'm guessing it's the resistor like you said and it would probably be easier to just replace.

RobH · 25 Feb 2008 at 18:20

Sounds like the dimmer switch is broken, there not too expensive to replace. The replacement bulb wasn't a compact fluorescent (energy-saving) by any chance as they are not dimmable (well most aren't).

ZG002 · 25 Feb 2008 at 20:32

Carl said:
When a lamp blows there is a earth fault and the RCD has detected this and is doing it's job.

Most installations you will find the lights are not covered by an RCD.

If he has only changed one lamp and the others used to dim then he has more than likely blown the dimmer switch. As said easy to replace and not too expensive. Just made sure you isolate the supply before swapping it over

Carl · 26 Feb 2008 at 13:36

ZG002 said:
Most installations you will find the lights are not covered by an RCD.

If he has only changed one lamp and the others used to dim then he has more than likely blown the dimmer switch. As said easy to replace and not too expensive. Just made sure you isolate the supply before swapping it over

Very true! ive mainly worked on splitload CCUs without lights being on the RCD side

Got this off another site, hope it makes all clear

"MCB's are very sensitive and will trip automatically when a circuit is overloaded. A blown light bulb can cause the MCB to trip; this is NOT a fault - the high sensitivity is a safety feature for your protection."

"MCB's operate when they sense an overload, or over current, and become an automatic switch, turning off, or tripping, the MCB when it detects such an overload."