Dimmer switch 'blown'

Possibly. I would say it is the fault current going through the dimmers winders (or electronics?) that have damaged the dimmer.

I damaged one last year by cutting through a lighting cable - there was probably 300-500 amps going through the dimmer for the time the earth and live were joined, until the circuit breaker tripped, just like when a lamp goes, it will cause a live to neutral fault current, which can be hundreds of amps for a short time.

You didn't buy the dimmer from B&Q, did you? I've had exactly the same problem and will soon be on my third one. Useless crap. Regards, Terry.

No but it used to happen to me a lot. In fact I even bought some cheap triacs in a box so I could replace them. Obviously now I don't use lights, but I never did understand why the system was so sensitive to momentary shorts. Brian

It's said a solid state device is there to protect the fuse supplying it. ;-)

In the fuse rather than MCB days, I've had a lighting circuit one blow when a bulb fails. Producing a dimmer which would stand that sort of load might be expensive.

get your money back. Or open it up and put in a bigger triac

Bulbs blowing often draw a surge of current (hence tripping the MCB for the circuit). Dimmers also often have an internal fuse. So that may have blown as well.

aka 'Triac'

So that may have

In article , John Rumm writes

The triac will sacrifice itself to protect the fuse.

Fit a new triac. It happens once every so many bulb blows, and yes, it is a pain. Use halogen-in-candle lamps and it'll happen very frequently. There are other ways to dim incandescent lamps, eg switching a capacitor in serie s with the bulb, or using a transformer to reduce voltage. Those can be don e at the wall switch, though the bits need extra space made for them.

NT

Although I probably could, I am not into faffing around 'fitting new triacs'. I just regard myself as being unlucky that my dimmer was the one that blew in those circumstances. S*it happens. I replaced it with a non-switching dimmer that I bought by mistake and if it goes then I will just go back to a conventional switch. Life's too short.

Or switching a series diode in and out, or wiring lamps in pairs so they can be switched in series or parallel.

Must confuse the pants off the unsuspecting electrician who comes to fault find.

Just done a quick count and I've got 18 dimmers here. Many of which over

Sometimes... the only time I had a dimmer fail on a bulb blowing, a new fuse in the dimmer fixed it.

s a pain. Use halogen-in-candle lamps and it'll happen very frequently. The re are other ways to dim incandescent lamps, eg switching a capacitor in se ries with the bulb, or using a transformer to reduce voltage. Those can be done at the wall switch, though the bits need extra space made for them.

I found that caused severe flicker. 120v lamps have much thicker filaments.

far too much dimming

NT

I'd say it must depend on the type of lamp in use - as well as perhaps the individual. I've used it with success - so worth just trying since a suitable diode costs pennies.