Dimmable CFL and buzzing from MCB

[rondamuk]

Hi

I have installed 7 Dimmable low energy lights (Megaman GU10 Dimmable 11 watt each), with a 1Kw Varilight Dimmer

I have checked the minimum and maximum lamps and I am ok on this front. However when I switch the lamps on there is a distinct buzz coming from the MCB.

The CU is brand new and I had it checked out by the elctrician who installed it and he says all is fine.

Is it the same as this post: //www.diynot.com/forums/viewtopic.php?t=127376 ???

and if so is there anything I can do about it?

Regards
Ron

 

[johnnykc]

Hi.......just wondering why with only 7 'low energy' lamps you require such a huge dimmer??...........you may have an underloading problem.

 

[rondamuk]

No, the rating for dimmers are not straightforward, minimum load is for the lamps should not fall below 1/6 of the min load (in this case 200/6 = 33, with 7 lamps we have 77W so this is ok)

Max wattage is similar but not to exceed 1/5, i.e. 1000 * 1/5 = 200 (so 77W is ok for this too.

Regards
R