Funwiring said:feed a room with 12-2 on a 20 amp circuit, feed the receptacles but branch in the switch boxes up to the lights with 14-2 or use 14-3 to run 3-way switches. Is that code acceptable?
Necdigest ?, February 2007
Compiled by Jeff Sargent and the NFPA Electrical Engineering Team
Q. Can I use 14-2 wire for the switch leg of a light fixture where the branch circuit is protected by a 20-amp circuit breaker? If this is against Code, why can I use 15-amp switches and receptacles on 20-ampere circuits?
A. The conductors from a switch location to the lighting outlet it controls are considered branch circuit conductors, not tap conductors connected to branch circuit conductors. These conductors are subject to the general overcurrent protection requirements of Section 210.20(B), which points to Section 240.4 for the specific overcurrent protection requirement. Section 240.4(D) specifies that 14 AWG copper conductors are to be protected by an overcurrent protective device with a rating or setting no higher than 15 amperes. And Table 210.24, which summarizes the requirements for branch circuits with two or more outlets or receptacles, specifies that the minimum conductor size for a 20-ampere-rated branch circuit is 12 AWG
Section 210.21(B)(3) permits a 15-ampere receptacle to be connected to a 20-ampere rated branch circuit. The terminals of feed-through type receptacles rated 15 amperes are tested for the heating that will result from the full load of a 20-ampere branch circuit. In addition, the attachment caps of cord-and-plug appliances are configured based on the appliance load. If the appliance is rated greater than 15 amperes, its cord cap will not be compatible with the configuration of a 15-ampere receptacle.
Snap switches installed on branch circuits are subject to the load requirements specified in Section 404.14. For AC general-use snap switches controlling resistive or inductive lighting loads, the minimum rating may not be less than the load it supplies. In other words, a 15-ampere switch installed on a 20-ampere circuit may supply a load of 15 amperes. For switches controlling lighting outlets supplied by 15- and 20-ampere branch circuits, it is the load controlled by the switch, not the rating of the branch circuit, that determines the switch?s minimum ampere rating.
Jim W in Tampa said:This is why we need inspectors.Short cuts and poor wiring habits are stoped fast cause they get caught.While 14-2 and 14-3 would work it is not safe or legal.Just where are you located and do they even license the contractors ?
Many areas of states like Pennsylvania and New York do not license electricians. I'm sure there are others as well.Jim W in Tampa said:This is why we need inspectors.Short cuts and poor wiring habits are stoped fast cause they get caught.While 14-2 and 14-3 would work it is not safe or legal.Just where are you located and do they even license the contractors ?
andinator said:I disagree that It would be unsafe. It would not be legal.
Jim W in Tampa said:What is unsafe is that unknown loads could be added.
Bob it is not about ampacity of #14 it is about #14 can not be fused/breakered at more than 15 amps.Its rated at 20 but fuse is 15iwire said:Jim what is the ampacity rating of 14 AWG copper at 60 C?
Jim W in Tampa said:Bob it is not about ampacity of #14 it is about #14 can not be fused/breakered at more than 15 amps.Its rated at 20 but fuse is 15
iwire said:Jim, as it's rated for 20 amps installing it on a 20 amp breaker is not unsafe it is just an NEC violation.
The NEC allows me to supply a motor load of 20 amps with 14/2 AWG, the breaker might be a 50.
Jim W in Tampa said:And if 20 amps is safe on branch circuits of #14 then why did they make the rule to use a 15 ?
Funwiring said:Ok, wow, posted this morning and bingo, lots of comments. First, I did read the code thoroughly about 10 years ago, have the highlighted copy in the truck I work out of when wiring. Good idea. I just got a current copy and will bone up on changes since my last read. I live in Northwest Ohio. No inspection, no license required for wiring. It's nuts the things I see vs code here. Your feedback is appreciated. "Funwiring" is just that. My day job is working in an office and with people all day. For me, it's "fun" when I get out of the office and do some "wiring"... hands on stuff. Thanks for your replies.