240.21(A) says branch circuit tap conductors must meet the requirements of 210.19 & 210.20, which in those sections mentions the 100% non continuous load + 125% continuous load ratings to conductors and circuit breakers. Where does it talk about length of branch circuit tap conductors? I believe I got the requirements down for 10' tap rule for feeders, but I'm trying to compare feeder tap requirements with branch tap requirements and I can't find any requirements for branch circuit taps.
Branch circuit taps
- Thread starter cppoly
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
What is the load being fed by the "tap" conductors?
(A)(3) & (A)(4) help but (A)(3) is specifically for ranges & cooking appliances and (A)(4) is only based on ampacity.
So this covers ampacity, which looks like branch circuit taps are generally required to have the same ampacity as the branch circuit.
But what's the rules on branch circuit tap length?
don_resqcapt19; said:
I'm just looking for a general rule.
1) There is no general rule.
2) There is no such thing as a tap conductor which has an ampacity equal or greater than the supply conductor.
- Location
- Connecticut
- Occupation
- Engineer
If the "branch circuit tap" had the same ampacity as the branch circuit, it wouldn't be a "tap."
There is no general rule for branch circuit tap length. For cooking appliances, the taps shall be "not longer than necessary for serving the appliance." For individual outlets, other than receptacle outlets, tap shall be not over 18" long. For infrared lamp industrial heating appliances, there is no length limit, etc.
You must follow the rules for the specific type of branch circuit tap as shown in 210.19(A)(3) and (A)(4).
That's a good point about tap conductors... I took it directly out of the 2008 handbook though:
"Tap conductors are generally required to have the same ampacity as the branch-circuit overcurrent device. Exception No. 1 to 210.19(A)(4) lists specific applications in items (a) through (e) where the tap conductors are permitted with reduced ampacities. These tap conductors are required to have an ampacity of 15 amperes or more (14 AWG copper conductors) for circuits rated less than 40 amperes. The tap conductors must have an ampacity of 20 amperes or more (12 AWG copper conductors) for circuits rated 40 or 50 amperes."
"Tap conductors are generally required to have the same ampacity as the branch-circuit overcurrent device. Exception No. 1 to 210.19(A)(4) lists specific applications in items (a) through (e) where the tap conductors are permitted with reduced ampacities. These tap conductors are required to have an ampacity of 15 amperes or more (14 AWG copper conductors) for circuits rated less than 40 amperes. The tap conductors must have an ampacity of 20 amperes or more (12 AWG copper conductors) for circuits rated 40 or 50 amperes."
- Location
- Illinois
- Occupation
- retired electrician
No, because the connection is not really a tap. A "tap" is a conductor that is protected by an OCPD with a rating greater than the ampacity of the conductor.
The "tap" to the receptacle must have an ampacity that is equal to or greater than the rating of the branch circuit OCPD.
JoeStillman
Senior Member
- Location
- West Chester, PA
If the tap ends in an OCPD, then the thing you tapped isn't a branch circuit anymore. It's a feeder.
- Location
- Connecticut
- Occupation
- Engineer
You can't supply a receptacle outlet with a branch circuit tap.
- Status