advice needed - changing to a dimmer

[Judders]

Hello all,

I've recently had the regular light fitting in my front room changed for some downlighters. But I think I've overdone it a tad. I now have 8 x 50w downlighters and to say they're a tad bright is an understatement So, i'd like to change my normal switch to a dimmer if possible.

The problem is, i'm struggling to find a double dimmer (double switch also controls the dining table light too) with enough wattage to support the 400w It needs to be a brushed stainless type of switch to fit in with our plans for the rest of the house, or I might be resigned to changing the bulbs to lesser wattage (would this be a good idea anyway??).

Any suggestions would be greatly appreciated!

justin

 

[breezer]

change lamps would be easier, you also do not say the voltage as this is important as you may have to down rate the dimmer.

better idea take lfitting back tell them it weighs too much, and you only got it because you thought it was light

 

[Judders]

change lamps would be easier, you also do not say the voltage as this is important as you may have to down rate the dimmer.

better idea take lfitting back tell them it weighs too much, and you only got it because you thought it was light

Changing lamps would be my second choice really.

They're recessed low voltage downlighters with individual transformers and as I've drilled holes in my ceiling - taking them back isn't an option!

 

[breezer]

read my post again, its my sense of humour.
before you even think of buying a dimmer are the transformers dimable (not all are)

 

[theshogun]

You will have to change your existing light switch box to a 2 gang box if you want a 2gang 400w dimmer switch.
Mk do a chrome type 450w/360va lv transformer controlling dimmer but you would have to check that your transformers are compatible with this .
Look on the Mk website (decorative accessories).

 

[Judders]

The transformers are dimmable - thankfully!

Thanks for the MK tip. Looks like just the ticket and their local disti just so happens to be the same place that I bought the LV downlighters from. I'll pop down there tomorrow

Cheers.

 

[Lectrician]

Read the spec carefully on the MK dimmers. They only support a certain amount of transformers per dimmer. Even if the wattage was ok (which it isn't, it 360vA for LV), you have 8 trannies, and from memory, the 400watt MK dimmers can dim a max of 5.

 

[ban-all-sheds]

I know these aren't the values in this case, but it makes the example easier.

How can the MK dimmers tell the difference between 8 50W loads and 5 80W ones?

 

[breezer]

since you raised the point i wondered that too, the "5 transformers" could even be 210w each, dimmers are rated by max dimming capacity, not quantity

 

[kendor]

as the output of these dimmers are triac based the total inductance could be a rating factor alongside the load rating? hence the number of transformers.

 

[Lectrician]

Don't know, don't care

Just giving you a heads up as to the spec!

 

[Judders]

I popped in to Wilts yesterday and they've ordered me a suitable dimmer in stainless for about £25. Just what I needed. Fingers crossed that it works

 

[Mr Dimmer]

Out of interest, the 5 transformer restriction is Mk being cautious. The reason they suggest this is that the very cheapest transformers use poor quality capacitors. This will cause a "capacitance ringing" problem when they are ganged up (more than 5). This causes the coil in a dimmer (all leading edge dimmers) to resonate, thus causing excessive noise and eventually burning out the dimmer.

Therefore, unless you are sure of your transformers, this restriction should apply to all dimmers, regardless of the size of the transformer or dimmer.

Hope this is of some help

John

 

[ban-all-sheds]

Yes - that is of great help - makes sense now.

BTW - Judders - I've just realised that you might have misinterpreted this:

change lamps would be easier

"lamps" is the correct word for what most people call "bulbs".