Heat concern regarding 1G 2W 1000 watt dimmer switch?

[1shortcircuit]

I'm looking for some advice if I may please.

After fitting a Varilight polished chrome 1G 2W 1000 watt dimmer switch I became concerned at how warm the faceplate was getting when the switch was turned to full power. It did seem to reach a peak temperature and not get any hotter but on operating it you were automatically drawn in to thinking of the temperature rather than it's operation being a subcontious effort (If that makes sense? lol)

There are no trapped or warm cables within the back box and the back of the unit is nowhere near the temperature of the faceplate. It functions fine and there is no abnormal smell. (Only one way being used)

This dimmer switch is operating 2 spot lights that each contain 6 gu10 50 watt lamps (600 watt total) The minimum wattage is 200watts and maximum 1000watts so evrything in theory seems fine - Unless there is something that I have simply unaware of. It is the first time I have had to fit a dimmer to lights that draw so much current and want to ensure that I am able to go to sleep and not learn of a building that has burnt to the ground due to the faceplate getting so warm.

I'm aware that the device will create heat and this will need to go somewhere but I just want to ease this concern.

Has anyone else had issues with these types of units or is it in fact perfectly normal just like the very slight buzzing that the manufacturers explain too?

All help is very much appreciated

:thumbsup

 

[malcolmsanford]

Because of the loads associated with halogen downlights it was always advised that you should derate a dimmer by at least 40% and sometimes 50% depending on the make and quality of the unit

As you say you have 600watt there and if you derate your 1000w dimmer by 50% then that is a load of 500w and your load is over that.

I know a lot of the better quality dimmers say you now don't need to derate, but yours may not be that good a quality and needs to be derated. Try using 35watt lamps and see if that is better.

 

[Marvo]

A 1kW dimmer will produce a substantial amount of heat. If it's not smelling like hot plastic or burning I would say that all you can do is check the terminations and check the current in the circuit isn't higher than expected on full brightness.

 

[i=p/u]

i would say as long as not more than 55 degrees

 

[1shortcircuit]

Because of the loads associated with halogen downlights it was always advised that you should derate a dimmer by at least 40% and sometimes 50% depending on the make and quality of the unit

Was this ever documented anywhere in any of our wiring bibles?

A 1kW dimmer will produce a substantial amount of heat. If it's not smelling like hot plastic or burning I would say that all you can do is check the terminations and check the current in the circuit isn't higher than expected on full brightness.

I agree and the heat has to be released somehow. The dimmer dial itself does not get warm it is just the surrounding faceplate. Is it possible that this unit would have been designed to get rid of the heat in this manner?

I've satisfied myself that all APPEARS to be correct but it's just the amount of heat that can be felt that is playing on my mind

I have gone back through and checked terminations



Manufacturers wording

Check the label on the back of the dimmerswitch before wiring it up. The label tells you the maximum load for the dimmer and also the minimum load. Calculating the load for each dimmerswitch module is easy. Just add up the wattages of all the bulbs that the dimmerswitch module controls

Thanks for all your posts so far

Regards

1SC

:thumbsup

 

[malcolmsanford]

Before the advent of halogen downlights you would normally derate a grid assembly row of dimmers, such as MK and Leviton both advised this or fit an upgraded faceplate.

Since the use of Halogen fittings as I said most decent modern dimmers would have no problems with the ratings, but with so many cheap and nasty units now available I always like to make sure that I allow about 40% just to be on the safe side.

As I suggested try 35watt lamps and see if it affects the temperature. I've attached an old MK grid switch pdf, though not really relevant as such, but it does show that a 1000watt tungsten grid switch should be derated

http://www.mkelectric.com/Documents...Devices/Grid Plus/Grid dimmer instruction.pdf

 

[1shortcircuit]

Thanks Malcolm, I will have a browse through that for sure :thumbsup

The joys of Google

Whilst I have emailed Varilight I have been browsing the net for similar concerns and this was one that I spotted almost immediately which has started to put me more at ease.

This is not related to Varilght

Is it normal for wall dimmer module to get warm to the touch?
All the dimmers we sell use an electrical component called a triac. A triac is a semiconductor, like a transistor, which can vary the amount of electricity it can pass. As electricity flows through this component, heat is built up and must be dissipated somewhere, most commonly it is dumped into the metal mounting bracket. This is the metal plate on the front of the switch. This heat in turn is transferred to the switch cover plate.

In most cases, it is not noticeable when the dimmer switch is driving a single bulb or a load of 100 watts or so. The heat does become more noticeable when the wattage of the load gets above 300. All single gang dimming wall switches must be able to dissipate one watt of internal power (heat) for every 100 watts of controlled load. At full load, this pushes the internal and external temperatures to the safe limits imposed by UL. This isn't to imply that higher wattage ratings are dangerous. As long as the total wattage is below the rating printed on the dimmer, you can rest assured that it is safe to use in your home.

All the wall switches we sell are approved by a nationally recognized testing service, typically Underwriter's Labs (UL). During the development of our SwitchLinc dimmer, we stress tested it by connecting it to a 1500-watt halogen floodlight for 24-hours. This switch was rated for only 600-watts, but we wanted to make sure that it could handle much more safely. It was left on for 24 hours and was still driving the floodlight at the end of the test. The heat radiated by the switch was so intense that all the plastic had melted and deformed around the switch. While it could no longer be used as a regular switch because of the plastic deformation, the switch never smoked or caught on fire.