Buzzing noise from MCB

[coopersim]

I have recently replaced a 1 gang two way switch with a 1 gang two way dimmer rated at 850 watts suitable for use with low voltage lights

connected to this are 9 50watt low voltage fittings each with their own 60 watt low voltage transformer

since I have fitted this I have noticed that the 6amp MCB on the dist board buzzs when the lights are turned on

the lamps all appear to be working correctly and do not flash etc when dimmed to a low level

the dimmer is not getting too hot and is not buzzing itself (it is a electronic type rather than a wire wound type)

I would like to know if there is anything to worry about, or if this is normal?

thanks.

 

[big-all]

heeelllooo coopersim

is 60w the input or output!!!!!!

if your on 60w x9 your approching 3amps [well just over2 ]
if its say 80w input its just over 3amps !!!!

what else runs off the lighting circuit!!!
wonder what the loss is for the dimmer!!!

if youve got a few other "spots" youll soon mount up on your demands and get nearer to the 6 amps [approximatly 1350w]

you only need a mixture of 10 x 60w and 100w to be up to your maximum 6 amps

 

[coopersim]

the intersting thing is that the lights are original to the house, and neither the bulbs, fittings or transformers have been changed

before the dimmer was installed the MCB was as quiet as a mouse !

 

[big-all]

mmm maybe there is an extra load wether or not the dimmer is in use!!!!![although i doubt any consuption from the dimmer is on full]

why dont you trip out and reset the mcb that might help!!!!

 

[Adam_151]

With a dimmer installed, the current wave form will be pretty nasty... its full of sharp corners (incase you didn't know, a dimmer switch works by cutting bits out of the nice smooth sine cure reaching the lamps)

What you are hearing is magnetostriction in the coil in the breaker, its an effect thats there regardless but when there is a nice smooth 50hz sinewave, there is probably some inbuilt immenuity to it as well as the fact that its going to be less 'violent' in its actions. You could try swapping the breaker out, its possible that its been badly made, if if you get ELFI checked you could swap it out for a type c which will have a shorter coil, or even a fuse

 

[securespark]

That must be it then. The nasty sharp corners are not running smoothly through the MCB, causing it to cry out in pain.

 

[coopersim]

this is what i assumed as it is an electronic rather than wire wound dimmer. so, the noise i can hear, will it be a problem, or can i just ignore it?!

 

[securespark]

Is it easy to replace an MCB? Are they Plug-ins?

 

[Taylortwocities]

Are they Plug-ins?

Crabtree, Square D

TTC