Have you ever seen a 40 A rated receptacle ? Look at it like this: There are situations where it is necessary to use a 15 A breaker with
12 or 10 wire. This would be done to accommodate for voltage drop. You are not violating any rules. The receptacle is rated above
and beyond the amps you are supplying.
I was looking at Table 210.21(B)(3) that lists Receptacle Ratings.
Why is it OK to put a 50amp receptacle on a 40amp circuit?
Have you ever seen a 40 A rated receptacle ? Look at it like this: There are situations where it is necessary to use a 15 A breaker with
12 or 10 wire. This would be done to accommodate for voltage drop. You are not violating any rules. The receptacle is rated above
and beyond the amps you are supplying.
So, what happens when I try to draw 50 amps thru wire and breaker thats only good for 40a.
Just because the receptacle is rated 50 A the breaker at the panel will limit you to 40 A. In certain situations we can say put a 40A
breaker on 12 AWG, air conditioners come to mind.
Yes, You can put a 40a breaker on #12 because of the next size up rule, that makes sense.
So why not alow a 20a recept to be fed by a 15a breaker? Same thing.
Thanks for your thoughts on this, still trying to wrap my mind around it. :?
Yes, You can put a 40a breaker on #12 because of the next size up rule, that makes sense.
So why not alow a 20a recept to be fed by a 15a breaker? Same thing.
Thanks for your thoughts on this, still trying to wrap my mind around it. :?
A 20 amp single receptacle is permitted on a 15 amp circuit.
A 20 amp single receptacle is permitted on a 15 amp circuit.
Not true. If you have a 20amp receptacle it must be supplied by at least a 20amp circuit. Table 210.21(B)(2)
You are probably thinking of putting a 15a receptacle on a 20a breaker, because its rated for 20a feed through current.
(2) Total Cord-and-Plug-Connected Load. Where con-
nected to a branch circuit supplying two or more receptacles
or outlets, a receptacle shall not supply a total cord-and-plug-
connected load in excess of the maximum specified in Table
210.21(B)(2)
You could'nt have a 40a breaker protect #12 wire because of the next size up rule, you could only do this if there was an overload device downstream of the 40a breaker, such as a thermal overload or or other overcurrent device used on the line side of a motor load. The 40a breaker would be the short circuit protection not the overload protection.
If the overloads were not in place you would be required to protect the #12 wire with a 20a max overcurrent device.
You can think of the receptacles like a balloon. if we have a balloon that will hold 50 psi and we only fill it with 40 lbs of air it will hold that pressure no problem. Now, if we have a balloon that is only rated at 40psi and we fill it with air to the point it exceeds 40psi then the ballon will pop. (simulating an overload). The only diffence is that in electricity we have breakers in place so that if load exceeds 40 amps it trips and shuts the circuit down before damaging the conductors.
You're incorrect. The table that you've mentioned is not for single receptacles.