- Location
- Illinois
- Occupation
- retired electrician
White Book.
Use a 600W Toggle dimmer in a 20A circuit?
- Thread starter Hormel1144
- Start date
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Hormel1144
Member
- Location
- NYC
Would you care to elaborate, by citing what you base that statement on? Sadly, if it is only based on your experience or opinion, even if it is correct, it doesn't carry any more weight than someone else's undocumented opinion to the contrary.
- Location
- Massachusetts
I have elaborated on it, perhaps you could read more carefully.
- Location
- Massachusetts
Hormel1144, You may want to look at the ROPs for the 2014 NEC, specifically 9-118 Log #726 NEC-P09 Final Action: Accept in Principle
(404.14(F) (New) )
(404.14(F) (New) )
mwm1752
Senior Member
- Location
- Aspen, Colo
"Can yoh guide me to where the code says that 15A switches are allowed where there the branch circuit won't exceed that 15A, even though 12ga wire is required throughout? " quote
Yes you are busting my b----ls - I did give you an example -- it answered your question as read.
A dedicated 16 amp motor cannot have a 15 amp switch controlling it. The same would be true if you loaded up a 20 amp lighting continuous load to the max @ 16 amps ( how many times have you seen this in residential) . If this 20 amp circuit has more than 16 amps it is non compliant with code. So your argument is more of the 15 amp snap switch not handling the 16 amp max load described above. It would not be the circuit fault that trips the breaker to burn the switch up but the continuous load during use to do so. Most devices & wire have a continuos load rating and I would not be surprised if that rating was not based upon a lower percentage of it's actual max.
Loads such as using a 15 amp duplex on a dedicated 20 amp circuit are allowed. If you used a single recept then the rating of the device would be 20 amp.
Yes you are busting my b----ls - I did give you an example -- it answered your question as read.
A dedicated 16 amp motor cannot have a 15 amp switch controlling it. The same would be true if you loaded up a 20 amp lighting continuous load to the max @ 16 amps ( how many times have you seen this in residential) . If this 20 amp circuit has more than 16 amps it is non compliant with code. So your argument is more of the 15 amp snap switch not handling the 16 amp max load described above. It would not be the circuit fault that trips the breaker to burn the switch up but the continuous load during use to do so. Most devices & wire have a continuos load rating and I would not be surprised if that rating was not based upon a lower percentage of it's actual max.
Loads such as using a 15 amp duplex on a dedicated 20 amp circuit are allowed. If you used a single recept then the rating of the device would be 20 amp.
Hormel1144
Member
- Location
- NYC
Dear Mr. Iwire,
Please remember that if I had the same resources as you I wouldn't have needed to ask the forum my question in the first place. Could you please tell me what it says? (And did you ever hear about the student who, in response to the question on an exam asking him to quote the Magna Carta, answered "Please refer to the 7th Edition of Webster's Dictionary. It's all in there") Please don't be like that in your response.
Thanks
kwired
Electron manager
- Location
- NE Nebraska
The devices are not protected by the breaker. That is very common with both wired and plug-in loads. Breakers are there to protect the wiring.
It is your responsibility when installing the dimmer to make sure that the connectec loads are within its capacity.
You could easily have three separate controller lighting runs, each with its own dimmer, on a single 20 amp branch circuit.
Sometimes a homeowner would put larger bulbs into recessed lights or add heads to track lights and overload the dimmer. Not much the electrician can do about it.
If using 600W rated dimmers bothers you, think about the fact that there are also ones rated for only 300W. And that if you put multiple dimmers in a multi-gang box you may need to derate them. And that the center one is a 3-gang box will be derated more than the outside two.
I can see, sometime in the distant future (next year at the rate we are going?) there will be fixtures, switches, and dimmers that all communicate back with the panelboard which will warn you if you are using things beyond their capability. The built in nudge/nanny.
And sometimes it will get things wrong and you will be screwed.
Sadly like AFCI's, it probably will be mandated that we install it before it has been made reliable enough for the market through lobbying from manufacturers to the CMP's.
I did not thoroughly read all the posts so hopefully not repeating something here - but don't let the know it all management know the lampholder in those luminaires is likely only rated 660 watts maximum or that the luminaire has a label limiting it to 60/75/100 watt lamps and is on a 15 or 20 amp circuit.
Or do let them know, and maybe secure yourself some work either finding luminaires rated for 20 amps or installing some kind of overcurrent protection for every luminaire and low current rated switch they have.
- Location
- Massachusetts
That is not what I did, I gave you a very specific place to look and as was pointed out you have access to those documents.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
That is not what I did, I gave you a very specific place to look and as was pointed out you have access to those documents.
I looked at all of the Panel 9 archives I could find linked on that page, and found
1. no 9-118,
2. a log #726 which was not relevant, and
3. some comments related to 404.14(A) which appeared to be on-topic, but no mention of (F).
Can you be a little more specific?
- Location
- Illinois
- Occupation
- retired electrician
I think that Bob intended to reference the ROP for the 2011 code, not the 2014. 404.14(F) was new to the 2011 code.
PetrosA
Senior Member
- Location
- Lancaster, Pennsylvania
Doesn't the whole premise strike anyone as asinine to begin with? Based on the premise of not using devices rated lower than the OCPD, we'd have to use a 5A max breaker for a 600W dimmer and each dimmer would require it's own circuit. Five amp breakers are not even available to fit the common types of panels. Either the premise is faulty or there are tens of millions of illegal dimmers installed across the USA.
- Location
- Massachusetts
Yes, I specifically screwed up. :slaphead:
Yes, it was the ROP for the 2011.
TheCats
Member
- Location
- Los Gatos, CA
Load rating vs circuit rating
Load rating vs circuit rating
The "600W" rating for the dimmer isn't an issue.
It's the maximum rated load for the device, but exceeding that load shouldn't cause a safety problem for the wiring.
The dimmer may fail, but any overheating or fire should be contained within the case.
For the devices I've dealt with the protection is usually implemented as a flameproof resistor. It's primary purpose is to damp the input current surge, but it also acts as a fuse. I'm guessing that a incandescent dimmer is more likely to use a thermistor on the control side of the thyristor, perhaps combined with a thermal fuse (resin pellet switch, which releases the spring-loaded contacts when the pellet melts)
Load rating vs circuit rating
The "600W" rating for the dimmer isn't an issue.
It's the maximum rated load for the device, but exceeding that load shouldn't cause a safety problem for the wiring.
The dimmer may fail, but any overheating or fire should be contained within the case.
For the devices I've dealt with the protection is usually implemented as a flameproof resistor. It's primary purpose is to damp the input current surge, but it also acts as a fuse. I'm guessing that a incandescent dimmer is more likely to use a thermistor on the control side of the thyristor, perhaps combined with a thermal fuse (resin pellet switch, which releases the spring-loaded contacts when the pellet melts)
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