You don't understand english very well - particularly when boolian logic is involved.
"not less than" means exactly that. Equal to or greater than equals not less than. PERIOD.
And a 15 amp breaker does not LIMIT current - it interrupts current when current excedes the limit. Limitting current would controll the current by reducing voltage to hold the current to the maximum limit.
A 20 amp 115/125 volt receptacle also accepts 15 amp plugs perfectly.
They do exist:
It actually makes a lot of sense, as I stated in an earlier post. What does NOT make any sense is a 15 amp plug on a 20 amp circuit
Not reasonable. You have a multibranch 15 amp circuit with 4 duplex 15 amp receptacles. You think it is only reasonable to expect to be able to plug 8 15 amp devices into the circuit?? Give your head a shake.
No, but I would expect to be able to plug in one 15 amp device, and I would be correct, unlike having a 20 amp receptacle on a 15 amp circuit, where the same expectation wouldn't be met. Must just be my Boolean logic
You obviously do not understand electrical theory any more than you understand the code book.
You explain to me how a 20 amp receptacle on a 15 amp fused/protected circuit is a safety issue.
Give it your best crack.
No, you are wrong. 100% The fuse is their to prevent damage due to, and protect against FAULT CURRENT. Any device, irregardless of it's rating, can draw excessive current due to a FAULT. And a 15 amp plug fits a 20 amp receptacle.
By your logic, twisted as it is, all 15 amp receptacles on a multi-branch circuit would have to be designed, built, and installed in such a way that if anything was plugged into one receptacle drawing close to 15 amps (or anything with a 15 amp plug, for that matter) , it would be impossible to plug anything else into any other receptacle on the circuit.
That's not the way it works (thankfully), nor should it.
The "ring wiring" system used (at least untill recently) in brittain and some parts of europe makes sense, with fused outlets. There is also a proposed standard (smart home) that would have each plug identify the rated current of the device and centrally monitor the current draw, shutting the device down if current ratings are exceded without shutting down anything else. This system uses RFID chips for identity - and yes - it IS being worked on - I know one of the engineers involved in the project.
guess i'll be breaking that rule then. I will NOT put a sump pump on a gfci. period.
I didn't say they didn't exist - just that they were so uncommon I never saw one.
lots of 20 amp plugged devices will actually run on 15 amps under "normal" conditions but can draw up to 20 (or even more) under cold-start or other special, but not fault, conditions.
And you can ONLY expect to plug in one 15 amp device if it is a DEDICATED outlet. - which is the only time a 20 amp receptacle IS allowed on a 15 amp circuit under current code.
Hey, I bought the place like this. It was vacant for nearly 20 years, the house was collapsed and I had to get a used trailer house until I built an actual house. The house was priority over the garage, and the following winter the roof fell, along with many other buildings in my area from heavy snow. There is only one remaining building now, a small barn (not including the 8 feet of old garage wall). This property was sold as "Farm Land" (no buildings), because they considered none of the old buildings salvagable. Well, I did salvage the old barn anyhow, and reused the garage foundation (cement floor). Plus I got a good well.
It's you who either can't read, or more likely, as usually, will not simply admit that there was something that you didn't know about and were wrong. I already pointed out that the table you are referring to, Table 210.21(B)(3), DOES NOT APPLY because it starts off by clearly saying right there in plain English that the table applies to circuits with TWO OR MORE receptacles. You do understand that TWO receptacles is not the same thing as ONE receptacle, don;t you?
Here again is what you are relying on to make your case:
We are talking about a SINGLE receptacle. The rules for receptacles are clearly seperated in the NEC into two cases, circuits with single receptacles and circuits with multiple receptacles. Multiple outlets are covered by the section with the table you keep trying to use. The code covers single outlets in the section just before it, 210.21(B) (1):
" 210.21 Outlet Devices. (B) Receptacles. (1) Single Receptacle on an Individual Branch Circuit. A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit."
Since 20 amps is greater than 15 amps, the 20 amp receptacle may be used on a circuit where it is the only receptacle. Following your process, one coud use a table in the code that says it applies to circuits less than 600 volts and apply it to circuits over 600 volts or vice versa. Somehow I think it doesn't work that way. Anyone who wants to read the sections in the actual NEC, and make up their own minds, which I encourage, it's available online here:
It's a good resource for everyone to have. After you have the book open, click on the TOC button in the lower left to bring up the table of contents, then go to section 2, flip through a few pages until you get to 210.21 It's all there in a few short, clear paragraphs.
Yes, I've seen and used plastic plate screws too.
This isn't much of a case of legalese, which is usually used to refer to long, winding sentences that are difficult to decipher. This is one short, direct sentence. Saying it can't be "less than" leaves open exactly two possibilities:
A - It can equal to
B - It can be greater than
Either of those options is valid and not restricted. If they wanted to retrict it to just A, all they had to do was say the receptacle has to be equal to the circuit rating.
Let's take some other examples. Suppose the law says that on a certain section of road you must maintain a vehicle speed not less than 40MPH. Would you argue they mean I can't drive at 55MPH? Or that a section of the plumbing code says a pipe must be rated not less than 160 PSI. Does that mean I can't use a pipe rated at 250 PSI ?
On that I agree with you 100%, which is why I brought up the issue in the first place. Like you and I think 99% of the rest of the world, I would not put a 20 amp receptacle on any 15 amp circuit, as at the very least, it leads to confusion.
trader already did in a perfectly good answer (below).
What a brilliant idea. We can ignore current trips at a little over the circuit rating and just trip on fault current - maybe 80A and higher.
I posted earlier that a 15A duplex receptacle is rated for a total 20A in both halves.
There have been a couple posts that a 15A receptacle is rated 20A wire-through.
You appear to have little idea of "the way it works". Perhaps the cold electrons in Canada behave differently.
Else you should stick to cars. There is no shock hazard and less to burn down.
[trader] I agree that 210 does not prohibit a single 20A receptacle on a 15A circuit
But a 20A receptacle is virtually never allowed under 406.3-B. It would make sense to at least point to 406 in 210. The logic is probably that
406 (Receptacles...) is the primary article and is modified by 210. There is a reference to 210 in 406.3.Most people would not be dumb enough to want a 20A receptacle on a 15A circuit (there seems to be one exception).
[RBM] There is text that you can put a 20A receptacle on a 15A circuit.There is no text in 210 that you can't have a higher rating, like 20A (or 50A, or 100A) as the single receptacle.
There is text in 406.3 that you can't put a 20A receptacle on a 15A circuit. This is what we all (except one) expect.
Maybe circuit breakers could include a feature that gives a delayed trip for motor starting current and incandescent inrush. Oh, wait, every circuit breaker already has that feature. And a lot of fuses.
And a device is not rated 20A because of momentary conditions. It is rated 20A (or over 15A) because that is what it draws under normal conditions.
Maybe you can in Canada, but in the US you can' install a 20A receptacle on a 15A circuit (406.3-B).
Far as I know, a switch doesn't need to be "self grounding". The NEC just requires metal screws and a grounded metal box. (Receptacles that use the mounting screws must be "self grounding".)
If I remember right, the argument was that you might have a plastic plate now, but someone could install a metal plate in the future.
I don't think the issue ever was what we expect. I would not have expected the code to allow a 20 amp receptacle on a 15 amp circuit either, which is why I brought it up in the first place. I also would not wire a circuit that way, because it's misleading at best. But what one expects and what is actually written in the code can be two different things.
I think there are actually three differing opinions on this subject. It looks like cl and I read the code as allowing a single 20 amp receptacle on a 15 amp circuit. Doug makes the claim, which I think is totally bogus, that the table in 210.21 (B) (3) says it is not allowed. But that is just plain wrong, because that table is preceeded by verbage that says it applies to circuits with two or more receptacles. I believe you and I agree on that point.
Then there is your position, which is that while not prohibited by section 210, it is prohibited by 406.3. That is a new point, which I had never heard used before. But let;s look at what that says. It doesn't actually say you can't put a 20A receptacle on a 15A circuit. What it says is this:
406.3 (A)"Grounding type receptacles shall be installed only on circuits of the voltage class and current for which they are rated, except as provided in Table 210.21 (B)(2) and Table 210.21(B)(3)."
A 20A receptable is rated to handle 0 through 20 amps of current. A
15 amp circuit falls in that range, so I would interpret the above to mean that the 20A receptacle is permitted. Especially in view of the fact that when they specifically address the issue of a single outlet they could have just said that in the case of a single outlet you must use a receptacle with a rating equal to the circuit, but they did not and instead said this:" 210.21 Outlet Devices. (B) Receptacles. (1) Single Receptacle on an Individual Branch Circuit. A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit.
Suppose instead of talking about receptacles, 406.3 talked about wire and said wire gauge shall only be installed on circuits of the voltage class and current for which it is rated. Would that mean that I couldn't use 12 gauge wire on a 15 amp circuit?
I don't see anything SAFETY relatee anywhere in trader's post. All he's talking is inconvenience.
Not germain to the discussion at hand. You guys seem to think it's your "god given right" to expect to be able to plug a 15 amp device into any 15 amp receptacle in a building and not have a breaker trip.
That can ONLY happen if every receptacle in the building is a split on a double breaker. I only know of one house where that is the case - every receptacle in the house is a 20 amp, separately supplied direct from one of several 400 amp panels distributed throughout the house. About half of them are also remotely switched. Took a very good electrician several months to wire that monstrosity.
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