wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
Personally, I think this belongs in 240.4(G), but given the trend established with the 2023 addition of 240.4(H), I'll submit it as a separate subsection.
240.4 Protection of Conductors.
Conductors, other than flexible cords, flexible cables, and fixture wires, shall be protected against overcurrent in accordance with their ampacities specified in 310.14, unless otherwise permitted or required in 240.4(A) through(H) (I).
. . .
(I) Service conductors protected by two to six overcurrent devices as allowed by 230.90 Exception 3 shall not require individual protection in accordance with their ampacity.
Statement of Problem and Substantiation for Public Input
230.90 Exception 3 allows service conductors to supply two to six overcurrent devices without having individual overcurrent protection. It further specifies "The sum of the ratings of the circuit breakers or fuses shall be permitted to exceed the ampacity of the service conductors, provided the calculated load does not exceed the ampacity of the service conductors." This is clearly in contradiction with the general rule in the first sentence of 240.4.
Since Article 230 may not amend the requirements of Article 240, in order for the allowance in 230.90 Exception 3 to be of practical use, 240.4 requires a corresponding exception.
240.4 Protection of Conductors.
Conductors, other than flexible cords, flexible cables, and fixture wires, shall be protected against overcurrent in accordance with their ampacities specified in 310.14, unless otherwise permitted or required in 240.4(A) through
. . .
(I) Service conductors protected by two to six overcurrent devices as allowed by 230.90 Exception 3 shall not require individual protection in accordance with their ampacity.
Statement of Problem and Substantiation for Public Input
230.90 Exception 3 allows service conductors to supply two to six overcurrent devices without having individual overcurrent protection. It further specifies "The sum of the ratings of the circuit breakers or fuses shall be permitted to exceed the ampacity of the service conductors, provided the calculated load does not exceed the ampacity of the service conductors." This is clearly in contradiction with the general rule in the first sentence of 240.4.
Since Article 230 may not amend the requirements of Article 240, in order for the allowance in 230.90 Exception 3 to be of practical use, 240.4 requires a corresponding exception.