Dimmer buzzing

[not so handy andy]

Hi, just wired up a new double dimmer switch and it's making a buzzing sound when the lights are switched on.

The double dimmer switch is a 2 way 400w

The bulbs are Eton GU10 5W LED and are dimmable.

The original switch was powering a bank of 4 lights, which are controlled of switch 1 on the dimmer, and switch 2 has another 4 lights which I've just installed.

When I removed the original switch there were 3 cables, mains power, supply to the light then a chain to feed another room I'm assuming? 2 brown live wires into com and 1 brown live wire into L1. Neutrals were connected together in a terminal block, as were the earths in a separate block.

Now when wiring up the dimmer I have an additional cable for the 2nd bank of lights. I've wired it up with the the original 2 brown live wires into the com on one side, with the brown off the 1st bank in L1. I've connected the 2 coms together using a separate piece of wire with the 2nd bank in L1.

Is this wired up correctly? If not can someone advise where I'm going wrong?

If wired up correctly then what is causing the buzzing noise?

Thanks in advance

 

[bernardgreen]

You have cinnected the Live to the wrong terminal Live should be in L1. Switched Live from the ~ with a line through it.

This however is not the cause of the buzzing. The dimmers are 60-400 watt so requires a minimum load of 60 watts.

There are problems with some types of dimmer being not compatible with some types of lamps and they operate in an un-stable mode. This abnormal node of operation can be the cause of buzzing.

 

[not so handy andy]

Ok so switch the live to L1 then do I put the wire currently in L1 into L2?

Do I leave the other 2 wires that are currently in COM as they are?

 

[bernardgreen]

Move all the wires ( Lives ) in ~ to L1 and move the Switched Live from L1 to ~

 

[Taylortwocities]

It will work with the wires either way round.

Re the buzzing: You need a LED compatible dimmer.

The load on each gang is 4x5watts = 20 watts

That dimmer needs at least 60watts to work correctly (or 60VA if you like)

Change the dimmer to one of these https://www.tlc-direct.co.uk/Products/VLJQP252W.html

 

[deadshort]

Hi, what's the variable control on the back of the dimmer for ? I can't find the instructions online.

DS

 

[Taylortwocities]

I think you can set the minimum dim level with that.
Anyway, that's acedemic. It's the wrong dimmer for those LED lights.

 

[mikeyd]

I'm not convinced it's the wrong dimmer for 20W of LED's.

http://www.arrowelectricals.co.uk/l...-1-gang-leading-edge-push-on-off-switch-p3731

looks the same from the back including EN number, and the specs indicate it should be OK with LED's between 5 and 50 Watts.
It also says on the back "Check instructions for ratings" and I can't find them online but the OP must have them.

NSHA: Does it buzz throughout the dimming range and is the light output what you expect? What do the instructions say?

 

[Taylortwocities]

Instructions (I found them on Google in 0.00000001 of a second) are here
http://www.sgd.ie/wp-content/uploads/2014/10/SLED-DIMMER-instruction.pdf

5-50W for LEDs. Instructions say dimmer will buzz.
Buy V-PRO dimmers. No buzzing if you buy a decent product.

 

[not so handy andy]

Move all the wires ( Lives ) in ~ to L1 and move the Switched Live from L1 to ~

View attachment 118303

Thanks for the advice Bernard, much appreciated! Changed the switch back to the original one, not happy with the buzzing so going to order the one recommended below.

It will work with the wires either way round.

Re the buzzing: You need a LED compatible dimmer.

The load on each gang is 4x5watts = 20 watts

That dimmer needs at least 60watts to work correctly (or 60VA if you like)

Change the dimmer to one of these https://www.tlc-direct.co.uk/Products/VLJQP252W.html

Again thanks for the advice mate, have ordered one of those. Was advised the one I bought was LED compatable. Instructions were missing from the package