Post
by ericmark »
Mon Mar 30, 2015 8:08 am
There are many options today with dimmer switches. The simple switch pull for on push for off and turn to adjust light level can often be used to replace like for like a standard two way switch. However the dimming is only on one switch.
There are also slave and master dimming switches still use three wires between the two switches but the matched pair both adjust the lighting level.
Better quality dimming switches declare the bulb sizes both min and max and some can work with LED and CFL as well as tungsten. But some require a neutral at the switch which is often missing.
Because CFL and LED units that can be dimmed are expensive and also often only the light level is reduced the colour stays the same today there has been a move to follow the European idea of 1/3 ~ 2/3 split in switching lights giving three light levels with simple switches and standard bulbs.
Dimming switches often come as leading to trailing and have to match the bulb used. Using bulbs and dimmers from same manufacturer works but when you try to mix manufacturers one can even with tungsten bulbs have problems.
Today you can't buy the old coiled coil Perl bulbs instead you get a quartz halogen in side a clear envelope this causes two problems.
1) The coil of wire in the bulb can cause the dimmer to malfunction.
2) The bulb life is reduced.
3) Bulb blowing and blow the dimmer.
The whole idea of the quartz bulb is the quartz is that hot the tungsten from the filament can't stick to the quartz instead it is re-deposed on the filament. Over time the thickness of the filament will vary until one bit gets too thin and the bulb blows, Some times because it is so hot when it blows it ionises the gases in the bulb which in turn is like a short circuit often seen as a flash when the bulb blows. This really high current will often take the dimmer out so it is common to have to change dimmer when bulb blows. Also if the quartz is not hot enough then the tungsten will settle on the quartz both making the filament thinner and coating the quartz with a black deposit reducing light output. So although quartz can be dimmer it is bad practice.
So step on is decide on bulb type. There are dimmers which fit into the lamp instead of the switch and you can even have a TV type remote control to work them.
I think the picture you show is the slave master type. So the single cable likely marked COM with go to the sine wave with arrow and the others likely marked L1 and L2 will go to new L1 and L2 but you will need to also replace the other switch of the pair. Without reading the instructions I can only guess but I think they are the type which sends a signal down the sine wave with arrow line to other switch. Some times it's another switch the same and sometimes they are slave master.
Do note at least 60W is required and no more than 250W some switches refer to load others bulb size. If load then at 50% dimming it will require a 120W worth of bulbs.
In my house early this year I removed the last of my dimming switches. As each room went to energy saving lamps so the dimming switches were removed. My living room had 6 x 60W bulbs now it has 10 x 3W bulbs dropped 360W to 30W and the room is brighter. Down side is no heat from lamps so had to change room thermostat to program type so warmer in the evening.
