Dimmable light and buzzing

[empirix]

Hi guys,

Got a couple of issues here, no doubt both are schoolboy errors. I am not an electrician (obviously) so please keep it simple ...

Just bought a fancy ceiling light with 15 x 20W 12V lights in, has an integrated transformer in the base.

Wired it all up with a std. switch and maybe 60% of the time it trips the circuit breaker. Presumably I need to upgrade the breaker, phoned the shop up and they said a "C" rated breaker would probably be needed. Had a look at the current breaker and it was labelled up B2 I think ?

Anyway, then changed the switch for a dimmer, rated 300W so in hindsight probably not up to the job ? Get a fairly loud buzzing both from the switch and the light itself. Certainly too loud to be able to live with it ... please help, do I need a commercial dimmer ?

Thanks

Paul

 

[mapj1]

Hmm, how many other lights are on the same breaker, and before you upsize the breaker from a B type to a C type, you need to know a bit more about the wiring - it is probably OK, but a willy nilly upgrade might not be wise, as the wiring may not like the larger fault currents it may one day have to handle, when you do want the trip to fire..
Usually lighting circuits are B6 wired in 1mm, or C6 or B10 wired in 1.5mm. Do you know the cable type and lengths involved?
As to the buzzing, many dimmers, unless they say otherwise react badly to transformer loads (and some electronic "transformers" react badly to being dimmed too.) It might be worth asking if that model is recommended for that application.

 

[empirix]

Thanks for the reply, its a brand spanking new house. Only 6 other standard ceiling lights on the "downstairs lights" circuit. Kitchen on its on circuit. So there isn't a a big load ...

Thinking about the breaker, I think it was a B6 (definitely not B10), just remember it being a B then a single number ...

Thanks in advance.

 

[cmct]

Your "buzzing " will be coming from the switch and the transformer. The buzzing is down to the type of circuit which operates the dimmer switch (SCR) and transformers are noisy anyway, due to the way they operate.

 

[empirix]

Checked last night and the breaker is definitely a B6, so am I ok to upgrade to a C ?

On the buzzing dimmer ... the shop say they have phoned the manufacturer who recommend that if a dimmer is required that a qualified electrician be consulted. Fair enough, but what will a qualified electrician do differently to what I've done ?

Thanks

 

[mapj1]

probably fit a dimmer that says ' suitable for dimming low voltage lamps' on the back and costs more. Still, its good, as it suggests the fitting is dimmable.