Transformers

[pburley]

Hi guys. I will be fitting three low voltage lights tomorrow. the bulbs are 20 watt, so do I fit a 60 watt transformer or is it better to fit a 80 or 105 watt transformer in case the end user desides to fit high wattage bulbs.

 

[nickblake]

me id go for the 105 va more reliable or better use individual transformers so you dont loose all the lights if one blows

 

[pburley]

Client want me to keep costs down, so I thought I would fit just the one transformer. There are other lights in room so if trans fails there will still be lighting.

 

[nickblake]

in that case go for the 105 va

 

[davelerave]

i'd rate the trafos according to fitting ie:50w


customer will prob replace the 20w halogen bulbs at some stage -may unwittingly decide to use 50watts

 

[pburley]

Nice one guys. Thanks for your help.

 

[Adam W]

Slightly off at a tangent but what are people's views on mini downlighters (eg Mini Downlights - Low Voltage), ie where do you put the transformer if the ceiling space is not accessible for replacing them bearing in mind it won't fit through the hole the light sits in?
Would you install one transformer in a 47mm backbox with a blanking plate, install it elsewhere, something else, or just avoid them like the plague?

 

[pburley]

Good question, along the same lines a friend wants down lights fittedd in his living room, unfortunately he lives in a block of flats and the walls and ceiling is all solid concrete. i've said I don't think it can be done unless he puts in a false ceiling. Is there any over way?.

 

[davelerave]

i'd prob avoid them-tricky to get the trafo accessible and they're not fire-rated

 

[nickblake]

Good idea but problem is you are limited with this type of transformer with the distance from the transformer its usually less than a meter , these days i try and use down lights with out the transformer GU10 low energy or F capped Firerated with heat forward lamps

 

[davelerave]

ya i generally use fire-rated gu-10 with led or cfl bulb

they should be fire-rated spots regardless of the bulb type

 

[pburley]

What lED bulbs do you use.

 

[pburley]

Sorry thats LED bulbs

 

[Adam W]

I totally agree about trying to avoid transformers - they're just a pain, but nobody seems to make a similar type of fitting which isn't low voltage.
I assume the 'less than a metre' rule is to do with volt drop so could probably be combated by using thicker cable.