9fixture of 60watt
- Thread starter aliasghar
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peter d
Senior Member
- Location
- New England
Re: 9fixture of 60watt
540 watts will cause a 600 watt dimmer to get quite warm. However, I assume that is perfectly normal.
540 watts will cause a 600 watt dimmer to get quite warm. However, I assume that is perfectly normal.
physis
Senior Member
Re: 9fixture of 60watt
If I remember right the triac itself inside the dimmer is guarranteed to run at 5% over the 600 watts but I think correct heat sinking is required. I used to run those things at 200% on the test bench. They didn't always survive that. They'd usually do 120% forever.
I would refer specificly to the dimmer's specs though. They don't have the best heat sinking. And the goofy stuff I used to do is no model for a permanent installation.
If I remember right the triac itself inside the dimmer is guarranteed to run at 5% over the 600 watts but I think correct heat sinking is required. I used to run those things at 200% on the test bench. They didn't always survive that. They'd usually do 120% forever.
I would refer specificly to the dimmer's specs though. They don't have the best heat sinking. And the goofy stuff I used to do is no model for a permanent installation.
B
bthielen
Guest
Re: 9fixture of 60watt
This raises a question that I've had before. I haven't been able to locate a code ruling for this either. When designing a lighting circuit, is there a rule of thumb or code reference that specifies a maximum number of outlets per circuit? There is no way of knowing what the future load may be. The homeowner might install 300 watt bulbs in a circuit that was designed for an average of 60 watts, and it wouldn't take long to exceed the rating of the circuit. Of course, some fixtures have limited ratings but what's to say they won't be replaced?
An example of this occurred recently with a friend. He had a bar with 10 recessed incandescent lights overhead on a single dimmer controlled circuit. He narrowly avoided a fire because the dimmer had a 600w rating that he was not aware of although I don't know for sure if that would have mattered. Anyway, he used 100 watt lightbulbs as he replaced those that burned out. His fixtures were rated for up to 100w and again, whether he would have taken that into consideration is unknown. Eventually his load exceeded the 600w rating of the dimmer switch and it began to get very warm. Luckily, the problem was discovered before a fire.
Not many homeowners are aware of the potential. Whether a light bulb is 40w or 300w, they both fit the socket so they are non the wiser.
Bob
This raises a question that I've had before. I haven't been able to locate a code ruling for this either. When designing a lighting circuit, is there a rule of thumb or code reference that specifies a maximum number of outlets per circuit? There is no way of knowing what the future load may be. The homeowner might install 300 watt bulbs in a circuit that was designed for an average of 60 watts, and it wouldn't take long to exceed the rating of the circuit. Of course, some fixtures have limited ratings but what's to say they won't be replaced?
An example of this occurred recently with a friend. He had a bar with 10 recessed incandescent lights overhead on a single dimmer controlled circuit. He narrowly avoided a fire because the dimmer had a 600w rating that he was not aware of although I don't know for sure if that would have mattered. Anyway, he used 100 watt lightbulbs as he replaced those that burned out. His fixtures were rated for up to 100w and again, whether he would have taken that into consideration is unknown. Eventually his load exceeded the 600w rating of the dimmer switch and it began to get very warm. Luckily, the problem was discovered before a fire.
Not many homeowners are aware of the potential. Whether a light bulb is 40w or 300w, they both fit the socket so they are non the wiser.
Bob
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: 9fixture of 60watt
220.3(B)(4) tells me that if I were to design a lighting circuit with a dimmer, then I would have to size the dimmer under the presumption that every luminaire would have the maximum sized light bulb for which it is rated.
If the homeowner installs light bulbs in excess of the luminaire's rating, then they create their own fire hazard.
220.3(B)(4) tells me that if I were to design a lighting circuit with a dimmer, then I would have to size the dimmer under the presumption that every luminaire would have the maximum sized light bulb for which it is rated.
If the homeowner installs light bulbs in excess of the luminaire's rating, then they create their own fire hazard.
Re: 9fixture of 60watt
220.3(B)(4) of the 2002 NEC may apply. At any rate, I think it would be a good idea to size the dimmer for the maximum wattage lamp that can be used in the fixture.
I think physis is right. Sooner or later, someone will put 100W lamps in the fixtures, unless they are rated for 60W max.
Steve
220.3(B)(4) of the 2002 NEC may apply. At any rate, I think it would be a good idea to size the dimmer for the maximum wattage lamp that can be used in the fixture.
I think physis is right. Sooner or later, someone will put 100W lamps in the fixtures, unless they are rated for 60W max.
Steve
electricmanscott
Senior Member
- Location
- Boston, MA
- Occupation
- Massachusetts Master Electrician, one man show.
Re: 9fixture of 60watt
On my installations I size for what ever the fixture is rated. If the homeowner wants to put one, two, three hundred watt lamps in that is their problem. If nine cans are rated for 65 BR 30 lamps max then I have no problem installing a 600 watt dimmer provided it is a single gang switchbox.
On my installations I size for what ever the fixture is rated. If the homeowner wants to put one, two, three hundred watt lamps in that is their problem. If nine cans are rated for 65 BR 30 lamps max then I have no problem installing a 600 watt dimmer provided it is a single gang switchbox.
aelectricalman
Senior Member
- Location
- KY
Re: 9fixture of 60watt
Whats the largest Wattage dimmer you've seen on the market for residential?
Whats the largest Wattage dimmer you've seen on the market for residential?
peter d
Senior Member
- Location
- New England
Re: 9fixture of 60watt
With all the fancy lighting control systems available these day, the possibilities are endless.
2000 watts for a single gang wall box style dimmer.
With all the fancy lighting control systems available these day, the possibilities are endless.
Re: 9fixture of 60watt
Why would you need a dimmer larger than 2000W for residential? A lighting circuit is limited to 20A, and I have never seen a lighting circuit higher than 120V in a residence (probably not allowed?). That limits the load on one circuit to 1920 watts. I think thats why the largest dimmer is rated at 2000 watts.
Steve
Why would you need a dimmer larger than 2000W for residential? A lighting circuit is limited to 20A, and I have never seen a lighting circuit higher than 120V in a residence (probably not allowed?). That limits the load on one circuit to 1920 watts. I think thats why the largest dimmer is rated at 2000 watts.
Steve
B
bthielen
Guest
Re: 9fixture of 60watt
I would have to agree with you, Charlie. It is impossible to control what will get done at some unknown future time so we can only use the information available at the time. This does lend support the idea that some method of proving competency such as licensing or tracking for inspection should be in place in order to even purchase electrical components. It's amazing how many co-workers, neighbors, friends, etc., get upset when I suggest they need to get their work inspected to be sure it's safe, even though all they maybe did was replace a broken light switch, receptacle, or other fixture. In Minnesota it is the law but it is nearly impossible to enforce on homeowners except for projects where permits are required. It is too easy and likely that improperly sized devices will be installed. When I bought my home, I discovered that the smallest fuse in my 60A service entrance was 30A rated. Except for the electric range, water heater, and electric dryer circuits, the largest wires used on any circuit was 14ga. I even found 100A fuses in the main disconnect supplying the home. To this day, I don't know how the house never caught fire. Needless to say, one of my first projects after replacing the fuses was to remodel the entire electrical system.
Bob
I would have to agree with you, Charlie. It is impossible to control what will get done at some unknown future time so we can only use the information available at the time. This does lend support the idea that some method of proving competency such as licensing or tracking for inspection should be in place in order to even purchase electrical components. It's amazing how many co-workers, neighbors, friends, etc., get upset when I suggest they need to get their work inspected to be sure it's safe, even though all they maybe did was replace a broken light switch, receptacle, or other fixture. In Minnesota it is the law but it is nearly impossible to enforce on homeowners except for projects where permits are required. It is too easy and likely that improperly sized devices will be installed. When I bought my home, I discovered that the smallest fuse in my 60A service entrance was 30A rated. Except for the electric range, water heater, and electric dryer circuits, the largest wires used on any circuit was 14ga. I even found 100A fuses in the main disconnect supplying the home. To this day, I don't know how the house never caught fire. Needless to say, one of my first projects after replacing the fuses was to remodel the entire electrical system.
Bob
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