Why does dimmer switch heat up?
I am doing some work for my neighbor. She told me that the 2 screws that attach the cover plate to the dimmer switch in the kitchen felt warm.
This switch is for track lighting in the ceiling. There are 7 fixtures in the track. Each fixture holds a 75 watt spotlight.
I pulled the switch cover off, and turned on the dimmer switch on high.
This is a three way switch. The 3-way switch at the other end of the kitchen is not a dimmer switch.
In a few minutes I felt this dimmer switch. It was quite warm. I could hold the back of my hand to it. It was not so hot that I couldn't keep my hand there, but it felt quite warm.
This didn't seem right to me. I read the writing on the switch. It said
"LUTRON
For permanently installed incandescent fixtures
1000W max 2 gang 800W 3 or more gang 650W"
Seven 75 watt lights is 525 watts. So it looks like the load was well under the max. I take it that this is a "2 gang" application.
Well, the switch getting that warm didn't seem right to me. I removed two of the fixtures. It was now running 375 watts.
At this point, the switch was still warm, but not as warm as it was with all 7 fixtures.
This lady had also asked me to replace a broken dimmer switch in the bathroom. I bought the best that Home Depot had, it was similar to the one in the kitchen. It is a Lutron, 600 watt max. It is not a 3 way switch. This goes to the lights at the vanity. There are 12 bulbs of 25 watts each, total 300 watts.
I removed the cover plate and turned the dimmer on high. To my surprise, in a few minutes this switch felt slightly warm, but not as warm as the kitchen switch.
What is the deal with these dimmer switches? Is it normal for them to get warm?
This switch is for track lighting in the ceiling. There are 7 fixtures in the track. Each fixture holds a 75 watt spotlight.
I pulled the switch cover off, and turned on the dimmer switch on high.
This is a three way switch. The 3-way switch at the other end of the kitchen is not a dimmer switch.
In a few minutes I felt this dimmer switch. It was quite warm. I could hold the back of my hand to it. It was not so hot that I couldn't keep my hand there, but it felt quite warm.
This didn't seem right to me. I read the writing on the switch. It said
"LUTRON
For permanently installed incandescent fixtures
1000W max 2 gang 800W 3 or more gang 650W"
Seven 75 watt lights is 525 watts. So it looks like the load was well under the max. I take it that this is a "2 gang" application.
Well, the switch getting that warm didn't seem right to me. I removed two of the fixtures. It was now running 375 watts.
At this point, the switch was still warm, but not as warm as it was with all 7 fixtures.
This lady had also asked me to replace a broken dimmer switch in the bathroom. I bought the best that Home Depot had, it was similar to the one in the kitchen. It is a Lutron, 600 watt max. It is not a 3 way switch. This goes to the lights at the vanity. There are 12 bulbs of 25 watts each, total 300 watts.
I removed the cover plate and turned the dimmer on high. To my surprise, in a few minutes this switch felt slightly warm, but not as warm as the kitchen switch.
What is the deal with these dimmer switches? Is it normal for them to get warm?
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Far as i know a dimmer switch creates more resistance to allow less current threw it should be a little warm. Might be a good idea to get a new one and see if that one heats up that much as well. 0 -
Dimmer switches are rated by the amount of watts they are designed to control.
If you try controlling too many lights, you fry the switch.0 -
Sorta like a valve on a water line. The dimer switch controls the amount of electricity that flows through it. In this case the friction from the electrons trying to squeeze through the reduced size conductor creates heat. That's my story anyway.
Smitty0 -
A little warm should be ok but I would start to worry if it was hot enough to burn someone or if it started to smell like it was burning. The dimmer switch is going to dissipate some energy in the form of heat. My guess is that new dimmer switches are extremly safe, you would probably pop a breaker before you could break the switch. 0 -
A dimmer switch is a variable resistor. It decreases the load to the line by increasing the load at the switch. That power is turned to heat.
All dimmer switches heat up. <<absolute statement
Of course, whenever I think I've stated an absolute, I find out I'm wrong.
Doug0 -
is there really a need for that many 75 watt bulbs, could 50 or 60 fill the need?
while even rated at 1,000 watts max it does not necessarily mean continuous, you can cut that to 60% for a longer life of the switch, remember watts is a measurement of heat, and if the switch is really heating up it is wasting energy
edit:as mentioned they do produce some heat0 -
Your answer lies here:
":LUTRON For permanently installed incandescent fixtures
1000W max 2 gang 800W 3 or more gang 650W"
You need to take the 75 watt spotlights out NOW!!!!!!0 -
Heat and dimmer switches go hand and hand.
Older dimmers had a potentiometer (which is a type of variable resistor, either rotating or sliding) as the method of controlling the semiconductors. The power to the light was not directly handled by the potentiometer, but by a semiconductor switch called a triac, which had a control signal provided to it by the potentiometer. These switches would build up a lot of heat and wasted a tremendous amount of electricity. Current dimmer switches use internal electronics to give the effect of dimming the lights and these can turn the light on and off 100+ times per second, far too fast for you to actually see but tricking your brain into thinking that the visable light is dimmer. This is far more economical than the older types with well over 80% of the electricity flowing into the switch geting used in the lamp. The heat that you feel is a result of the friction of the electricity flowing through the switch and modern electronic dimmers have a metal plate which serves as a heat sink which absorbs and then directs heat towards the room which prevents heat building up in the house wiring or the internal components of the dimmer switch, which in extreme cases could lead to fire.0 -
On the "gang" ratings, they are referring to the size of the box it's installed in. A box that will only hold 1 switch is a "Single Gang", a box that will hold 3 switches is a "3 Gang" box. The de-rating of capacity is in case of multiple dimmers in the same box (increased heating/decreased cooling capacity) 0 -
There are three types of dimmers:
1.Incandescent & Halogen, i.e bulbs at actual full 120V
2.Magnetic
3.Electronic for all lights that have an electronic step-down AC transformer powering the actual bulbs which are usually 12V AC each, regardless of wattage
If it's a contemporary track light with the step-down transformer somewhere underneath the housing along the track light's rail, then the conventional incandescent dimmer is the incorrect model. She needs to buy an electronic version upwards of 600W output. Same aisle and rack in the home centers as the others. It says it right on the lower right hand corner of the package.0 -
There are four switches in this same box. But, this is the only dimmer switch.
"Your answer lies here:
":LUTRON For permanently installed incandescent fixtures
1000W max 2 gang 800W 3 or more gang 650W"
You need to take the 75 watt spotlights out NOW!!!!!!"
I don't understand. There are five 75 watt bulbs. That totals 375 watts. The switch will take at least 600 watts.
Remember, I already removed two of the initial seven fixtures.
These fixtures are the type that has a little rim that fits right onto the spotlight. It is a separate piece of metal. Then, there is a fitting with the wire running to it, that the bulb screws into.
In the vast array of bulbs at Home Depot, there is only one bulb that fits this fixture, and it is the 75 watt.
Bear in mind, this track light has been in place now for five years. As far as I know this is the original switch.0 -
quote:Originally posted by allen griggs
There are four switches in this same box. But, this is the only dimmer switch.
"Your answer lies here:
":LUTRON For permanently installed incandescent fixtures
1000W max 2 gang 800W 3 or more gang 650W"
You need to take the 75 watt spotlights out NOW!!!!!!"
I don't understand. There are five 75 watt bulbs. That totals 375 watts. The switch will take at least 600 watts.
Remember, I already removed two of the initial seven fixtures.
These fixtures are the type that has a little rim that fits right onto the spotlight. It is a separate piece of metal. Then, there is a fitting with the wire running to it, that the bulb screws into.
In the vast array of bulbs at Home Depot, there is only one bulb that fits this fixture, and it is the 75 watt.
Bear in mind, this track light has been in place now for five years. As far as I know this is the original switch.
Again, I respectfully suggest that you may have the incorrect dimmer for these bulbs. If the bulbs are rated at 12 volts AC, regardless of wattage, then your track light has a transformer and requires the electronic dimmer. If it's really old, it may have a different circuitry and require the odd magnetic type of dimmer. Now, if your 75W bulbs are 120 volts, then the standard dimmer rated for 600W to 1000W should suffice.
If the dimmer you pulled is NOT a 3-way dimmer, then it should be replaced with one that is so that the 3-way feature is not lost. They even sell matching 3-way dimmers, one is the master and the other a slave, that work splendidly and allow dimming and on/off from either location.
Just some suggestions here, allen. Hope it all works out for you.0 -
[:0]it gona blow!![:D] 0
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