Chad Schloss
Member
Section 110.3(B) of the NEC states that any appliance of piece of equipment must be installed by the instructions so to install an appliance on a 20 ampere circuit when the manual states for it to be installed on a 15 amp circuit is a code violation.
As far as the appliance itself one could use jumpers from the meter base and the appliance wouldn’t care as long as it had current flow. The overcurrent device is installed to protect the conductors not the appliance so it wouldn’t care if it was wired straight to the transformer. Believe it or not but that surge protector or plug strip with the radio/tv/whatever plugged into it don’t care either but the owner might when the insulation starts smoking. These devices are one of the leading causes of fire in our homes today so why put them to the test?
It would only by a violation if there was something in one of the manuals for one of the appliances that called for a 15 amp circuit but common sense plays a role here also. When using things like extension cords and plug strips the fact that 18 gauge conductors are only good for 7 amps and 16 gauge conductors are only good for 10 amps why would someone want to plug one into a circuit that has 25% more heat energy available? Could it be that they believe that that 20 amp circuit is somehow better?
What role does 10 receptacles play in this discussion? This is a dwelling unit not a commercial or industrial installation where the load is calculated on the device but is instead calculated on the square feet.
In commercial and industrial installations all duplex receptacles are to be calculated at 180 volt amperes each. The reason for this is that one will not be installed unless it is planned on being used. In a dwelling unit we must install receptacles per 210.52 at regular intervals. These devices are sometimes never used so there is no need to figure them at 180 volt amperes each but instead at 3 volt amperes per square foot.
All of this thinking of 20 ampere circuits for dwelling receptacles and separating the lights from the receptacles comes from commercial and industrial installations. The adage was passed from the commercial trade to the residential trade through commercial electricians that only did commercial and industrial installations then one day doing a dwelling and using what they had learned.
A quick look at 210.21 through 210.23 one will learn that if a 15 amp receptacle is being installed then the maximum load that can be plugged into it is 12 amps and it doesn’t matter if it is a 15 or 20 overcurrent device.
So what does one gain by installing 20 amp circuits and not installing 20 receptacles? Nothing. What does one gain by installing 20 amp circuits and 20 amp receptacles? The cost of the 20 amp receptacles are twice that of 15 amp receptacles. Their only gain is more cost and a waste of our natural resources.
So is the 20 amp circuit for a dwelling unit better than a 15 amp circuit? It depends on who you talk with. Those that I talk with say no the 20 amp circuit is more dangerous than a 15 amp circuit. These are some of the greatest minds in the electrical trade not some master electrician that has retired nor is it some unfounded wives tale that was started many years ago. It is those who are charged with writing, testing, and researching the codes and installations for electrical energy.
i don't have the ability to recite code references, simply because i don't have a code book., and i am not an electrician by trade. i can read just as well as you. the wiring in the wall is protected by the 15 or 20a breaker in the panel. the appliance plugged into the outlet is fused internally. whatever you decide to plug into any outlet should have overcurrent protection. that OCP device should trip at 5a, 10a max, so even if the breaker were 15a on 14 ga wire, the breaker may never trip because the appliance OCP device will blow first. the breaker may never even open because of the curve designed into the breaker, which allows it to handle over the rated amount for a certain period of time before it trips. i still see no point from your comment other than it costs more. i wanted the lighting separate from the receps for convienence. i didn't do it for any other reason that that. i want the lights on if a breaker blows for a recep. seems like good practice, even if it is not code or over code to do so.
take your car for example. it has an alternator to supply current for your car. it really needs to be only about a 300w alternator to power the lights and recharge the battery. instead, automakers are making them bigger, beef it up to 500w, sometimes 800w or more for people who install high current amps in their car with big speakers. all that current is there to be used, if needed, to run gps,interior dvd players, etc. everything in your car has a fuse, and every item you plug into the cigarette lighter should have a fuse also. how does the amount of current the alternator puts out have any effect on the device plugged into it, other than sustaining what items are to be powered?
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