20 amp

[romex jockey101]

if theirs a 20 amp circuit and you want to run a lighting circuit off it can u run 14 awg or do you have to use 12 g i no light loads dont draw alot off amps and ive been using 12awg in this sinerio but was thinking 14 would save some money..im shure this is a easy question but was just woundering

 

[480sparky]

No can do.

 

[zombie]

240.4d

 

[charlie b]

The issue is not how much load the lights draw, but rather protecting the wires against overcurrent. A 20 amp breaker is not allowed to be the means of protecting a #14 wire.

 

[480sparky]

.........A 20 amp breaker is not allowed to be the means of protecting a #14 wire.

....... in this instance.

 

[Little Bill]

....... in this instance.

I've seen a lot of switch legs, mainly for 3-ways, that are 14-3 AWG and the feed conductors are 12AWG. I don't think this is allowed but not sure where some inspectors might just approve this. Is this allowed at all anywhere?

 

[romex jockey101]

....... in this instance.

i understand thats y i always use 12 i was just woundering...so if u were 2 come off of a plug with 14 and ran it to lights would the 14 g have the amperage thats is drawn thru the plugs i dont think so

 

[480sparky]

i understand thats y i always use 12 i was just woundering...so if u were 2 come off of a plug with 14 and ran it to lights would the 14 g have the amperage thats is drawn thru the plugs i dont think so

There are specific instances where #14 can legally be protected by a 20a breaker. But this isn't one of them.

 

[Dennis Alwon]

Think a/c units. 14 awg can be protected by a 25 or 30 amp breaker but that is because there is overload protection in the a/c. Lights don't usually have overload protection and if they did there is no exception for them.

 

[LarryFine]

I've seen a lot of switch legs, mainly for 3-ways, that are 14-3 AWG and the feed conductors are 12AWG. I don't think this is allowed but not sure where some inspectors might just approve this. Is this allowed at all anywhere?

Only where protected by a 15a OCPD.

 

[augie47]

It was an accepted practice in some areas here a number of years ago, but I know of no place that it is accepted now.
On occasion some ole guy like me will come out of retirement and use #14 switch legs cause "we used to do that"

 

[hurk27]

It was an accepted practice in some areas here a number of years ago, but I know of no place that it is accepted now.
On occasion some ole guy like me will come out of retirement and use #14 switch legs cause "we used to do that"

It was explained to me once by lets say a code expert, that the NEC never intended #14 to be protected over 15 amps if over loading the conductors could not be controlled such as with AC units and other motor loads, but because fixture wires was never defined until recently as to what was considered a fixture wire many assumed it applied to any conductors feeding a fixture which allowed switch legs to be smaller, If I remember right this was cleared up in the 1999 to 2002 code cycles.

Protection of #14 at 15 amps has been in the code book for a long time.

 

[broadgage]

As many others post, the use of #14 for switch legs on a 20 amp circuit is a clear violation of the NEC which requires at least #12 in all common circumstances.

It would in practice be safe, but still a violation.
The current is limited by the lamps used, hardly likely to exceed 15 amps on one fixture or small group of fixtures, therefore no risk of overload in normal use.
In the event of a short circuit, then #14 will easily handle the short term current required to open a 20 amp circuit breaker.

After all, 15 amp outlets are often wired on 20 amp circuits. No one worries about #14 or smaller appliance cords or extension cords on a 20 amp breaker.
Although Code treats fixed wiring and appliance cords differently, the laws of physics are the same.
#14 appliance cord on 20 amp breaker, permitted and safe in practice.
#14 romex on a switch leg from a 20 amp breaker, just as safe in practice but is a violation.

 

[romex jockey101]

As many others post, the use of #14 for switch legs on a 20 amp circuit is a clear violation of the NEC which requires at least #12 in all common circumstances.

It would in practice be safe, but still a violation.
The current is limited by the lamps used, hardly likely to exceed 15 amps on one fixture or small group of fixtures, therefore no risk of overload in normal use.
In the event of a short circuit, then #14 will easily handle the short term current required to open a 20 amp circuit breaker.

After all, 15 amp outlets are often wired on 20 amp circuits. No one worries about #14 or smaller appliance cords or extension cords on a 20 amp breaker.
Although Code treats fixed wiring and appliance cords differently, the laws of physics are the same.
#14 appliance cord on 20 amp breaker, permitted and safe in practice.
#14 romex on a switch leg from a 20 amp breaker, just as safe in practice but is a violation.

thank you for comment

 

[greenjeans]

As I have witnessed in many homes that some handyman or GC thinking they know little about everything wires a recessed light or extended an outlet using 14/2 off existing 20amp circuit. Why, I don't know, but when I come into these homes and see the poor wiring , the first thing i do is check the elec panel to see what size wire it is, if its 12 awg then I see if it on a 15amp breaker, if it is............COOL, if not, I change it to a 15 breaker. My reasoning is this, I see it, I verify it and I fix it. Being the last person to mess with it, it now my liability. Its also good service as way.....IMHO.

 

[greenjeans]

IMO, your mixing apples with oranges, the nec says, you cant, so don't, its not saving any money if the house burns down. I agree that some appliance cords are under rated, but they all have to be listed, witch is good enough for me. If the house burns down do to unlisted appliances. That's not my problem then. but, if I saw a safety issue with it , I would let the owners know.