humming noise when lights are on

oysterman

Had some downlights fitted recently but when there switched on there is a humming noise coming from the light switch & also the consumer (spelling) box, is it anything to worry about if it is what to do about it. Cannot contact electrician who fitted them he on holiday at mo.

real1314

is it a dimmer switch? how many downlights and what rating are they?

could be an overloaded switch, but downlights do tend to cause some humming.

oysterman

real1314 wrote: »

is it a dimmer switch? how many downlights and what rating are they?

could be an overloaded switch, but downlights do tend to cause some humming.

Yes it is a dimmer switch(double) 12 total, 4 off one & 8 off the other not sure of the rating thou

fazer_2

Relax, got a dimmer switch in the kid's bedroom which hums, can only hear it if it's super quiet in house or got my ear next to switch.

rsvtoddy

Suspect you've got too many on the dimmer - I was looking for one to do 7 50watt GU10 bulbs (350 watts total) and couldn't find one with enough wattage taking into account de-rating.

If you've got 12 bulbs (50W?) they'll fry the dimmer fairly soon! I hope your sparkie was suitably qualified/competent and gave you certification?!

model500

It's your dimmer switch, you'll maybe notice that the humming noise goes away when you turn the dimmer to the max setting ie: lights fully on.
Perfectly normal for these components, it's how it reduces the power to the light basically chopping up the voltage input.

maypole

I get a humming/buzzing noise from a lamp with a low energy light bulb from Ikea, really gets on my nerves :mad:

Dormouse

maypole wrote: »

I get a humming/buzzing noise from a lamp with a low energy light bulb from Ikea, really gets on my nerves :mad:

Yeah, I've got a lamp with a low energy bulb from Tesco and it buzzes too, pretty annoying. :rolleyes:

real1314

I've got 6 x 50 watt downlights in one room - had to use a double dimmer to get within the load for each of the switches, and also to allow reduced consumption.


I think most dimmers stipulate that you should treat halogen downlights as being double their value for loading purposes, some might say 50% extra allowance.

8 x 50 watts = 400watts, x 1.5 to 2 = 600 to 800 watts on a single dimmer = v expensive switch? or overloaded switch?

and just another point - lighting circuits are normally 6 amp, which gives a maximum load of about 1500 watts. Your lights in that room alone amount to 600 watts; might be worth checking if you've got separate circuits for upstairs/downstairs, and checking the load on the circuit.

jaxxy00

model500 wrote: »

It's your dimmer switch, you'll maybe notice that the humming noise goes away when you turn the dimmer to the max setting ie: lights fully on.
Perfectly normal for these components, it's how it reduces the power to the light basically chopping up the voltage input.

This happens to ours and when turned up to full you cant hear it. Saying that though i cant hear it that much anyway as a bit luggy

baldelectrician

There is a noise supressor in the dimmer (it is there to help prevent TV and radio interference- the kind you used to get when you turned a flourescant light on and yor AM radio crackled)


Dimmers should be suitably rated.
Some dimmers require de-rating (400w dimmer = 200w halogen)
Some don't require derating example below:
http://www.aurora-lighting.com/srspe.aspx?txtSearchTerm=dimmer&cmbSearchScope=Dimmers%20and%20Switches

Shop about (not B&Q / Homebase) ; use local electrical wholesalers.