Lighting Help

[padstar]

I had always thought that the max amount of lamps on a lighting circuit was determined by the total wattage of the lamps not exceeding the max load of the switch.

I am on the last room of the house which i had planned to have controlled by 2nr triple dimmer switches in the following set up

Switch 1 - Study Area
Switch 2 - Living Area
Switch 3 - Kitchen Area
Switcht 4 - Kitchen Feature Light
Switch 5 - Rooflight Feature Light
Switch 6 - Utility

The study and utility are done and working fine. I haven't installed the fittings yet but assume being only 1 fitting and 1 "rope light" to the kitchen & rooflight feature this will also be ok.

I have just connected the kitchen area which consists of 11nr 5w LED downlights (GU10/240v). With all 11 lamps fitted the lights come on and then shut down when on no dim. They all work on half dim or lower. I have removed 3 lamps and the rest seem to work fine. Am I right in thinking if i swap the 5w lamps for 3.5w lamps they will all work fine (8 @ 5w = 40w total / 11nr @ 3.5w = 38.5w total)?

What I cant understand is that the switch is rated at a loading of 5-150w. To me that meant I could have 30nr 5w lamps but clearly this is not the case. How does it work?

The issue i have is that the living area has large number of fittings on the 1 circuit ( i had used the logic above to tell me that 5w lamps would not be an issue no matter how many you have.

My question is - Are there any switches that will operate large numbers of fittings on a single switch? There must be commercial switches that do as office areas surely have large numbers of fittings.

We dot want to reduce the quantity of fittings if we don't have to as this would involve butchering the new ceiling, plus its a large area that we want to have well lit and there are feature areas with multiple fittings. Is there any way round this.

Also is a 3.5w lamp noticeably less bright than a 5w?

 

[padstar]

If i replaced the module for the kitchen and living area switch in the existing faceplate to one of <these> would that work?

 

[terryplumb]

Are the dimmers/LEDs compatible ?

 

[ericmark]

Well before LED came out, there has been a problem with too many lights on one switch, as tungsten has a lower resistance when cold to when hot, so on switch on there is an inrush.

LED's have many different ways of being driven, so they don't all act the same, but the simple method is a capacitor to limit current, full wave rectifier, then a large smoothing capacitor and leak resistor and the LED's, that smoothing capacitor will cause an inrush on switch on.

There are two major problems with LED's, one is not switching off, but remaining on dim, and the second is a shimmer when switched on, and the problem is nothing in the description helps know which will have problems and which will not.

I had the problem with G9 bulbs, the small one would flicker and stay on, fitted a load capacitor which stopped it staying on, but not flicker, but the larger one cured all the problems, and the smoothing capacitor inside it is nearly as big as the whole of the small bulb.

Most ceiling roses act as a junction box, and are rated at 5 amp, so most lighting circuits are limited to 5 or 6 amp, but regulations allow up to 16 amp for most bulb types.

I have some smart bulbs and some standard bulbs, I note a short delay when turning on smart bulbs, but unless one has an oscilloscope one is unlikely to be able to measure any inrush, yes my meter have data hold, so can set to min or max amps, but they are unlikely to show the inrush when switching on lamps.

 

[oldbutnotdead]

As @terryplumb , are the led lamps and dimmers of the same brand or from the same supplier or otherwise guaranteed to work together?
If you had switches, they would work. You don't have switches, you have dimmers. LED stuff is very specific as to what dimmer will work properly (unlike tungsten where any old tat would do).

 

[SFK]

Padstar
I would try a better dimmer.
My go to for LED dimming is the Varilight V Pro.

varilight v pro dimmer - Google Search

www.google.com

It should have no issues dimming 11 x 5W.

 

[padstar]

Thanks everyone.

SFK - it is the varilight v Pro dimmer module that I linked above. Doing some research they reckon they can handle 30 lights. I am going to pock one up and swap with the current module in my switch and see how good they are.

Fittings and lamps are the same manufacturer.

There is no flicker and lamps don't stay on.

Switch could be some pants parts pulled together to look fancy. Hopefully upgrading modules to the V Pro will help. Will let you know.

 

[winston1]

My question is - Are there any switches that will operate large numbers of fittings on a single switch? There must be commercial switches that do as office areas surely have large numbers of fittings.

They do but they are not usually all on one switch. Also office areas don’t use dimmers.

Also is a 3.5w lamp noticeably less bright than a 5w?

Well they are 30 % less power and you don’t get something for nothing. But your eyes are not linear.

 

[ericmark]

Also office areas don’t use dimmers.

This is the real problem, however lecture halls, etc do, often with fluorescent fittings, and the gear used to dim them is very expensive, so can be done, but not on the cheap, depends on how important dimming is?

I used GU10 lighting on my landing, I have the centre and outer lamps independently switched, so have a low light when everyone else in bed, but bright when I want a load of light, this method was used in places like Turkey for years, where tungsten lamps would make the rooms too hot, so they moved to CFL far earlier to the UK, and CFL do not easy dim, so arranged with a two gang switch so 1/3 or 2/3 of lights could be used, giving three levels of light.

 

[markyd1]

Have a look at the Zano controls range

 

[padstar]

Just to close this out if anyone ever has the same issue. I Went for 2 varilight v Pro modules and swapped them with 2 of the 3 modules in my triple dimmer.

Worked a treat. Thanks for all the advise and SFK for co firming the modules were up to it. I now have a full on light show in my extension. Yes I may have gone a touch overboard!.