by ericmark »
Mon Mar 21, 2011 5:13 am
The old transformers were large heavy items but in the main these have been replaced with inverters which are lighter and smaller.
The modern inverter will fit through the hole that a 50 mm spot light fits into however there is also the heat problem.
It has been found that many of the small 50 mm spot lights have caused charring of the surrounding woodwork and now we are very careful to fit hoods to prevent the heat reaching the woodwork.
422.3.1 Except for equipment for which an appropriate product standard specifies requirements, a luminaire shall be kept at an adequate distance from Combustible materials. Unless otherwise recommended by the manufacturer, a
small spotlight or projector shall be installed at the following minimum distance from combustible materials:
(i) Rating up to 100 W 0.5 m
(ii) Over 100 and up to 300 W 0.8 m
(iii) Over 300 and up to 500 W 1.0 m
NOTE: A luminaire with a lamp that could eject flammable materials in case of failure should be constructed with a safety protective shield for the lamp in accordance with the manufacturer's instructions.
This leaves us with a problem as often there is less than 0.5 m between ceiling and floor boards and although the hoods can be fitted through the hole it is not an easy job and then the hood stops access to the inverter.
All junctions with screw connectors must be accessible for maintenance and although I have seen hatches in floor boards in real terms once the carpet is laid there is no access.
The whole idea of the SELV lamps is the very carefully controlled voltage ensures the envelope of quartz is maintained at the correct temperature to reflect the tungsten so it is redeposited back on the element. However in many areas the voltage is stable enough to use low voltage (230 v) GU10 lamps instead. I have a couple in my bed room as reading lamps and the bulbs last for ages. However they are in pods so not overheated.
Using GU10 lamps also means as well as LED you can use cold cathode lamps or florescent and these give a wider angle than the tungsten spot lamp but being so close to where I read I have found the 11 W version has worked well. However the second one I bought would not fit the GU10 holder so I only have one.
I hate the flush fit 50 mm spot light. The pods fitted as designed to light pictures on the wall etc are OK. But the flush fit type make the ceiling look like a planetarium and give out about the same amount of light. I had to fit 10 x 10 W units in one room and a single 100W pendent lamp would have been too bright but the 100 W of spot lights were useless. Ended up using 2D florescent lamps and the 2 x 22 W lamps were if anything far too bright for the room.
