fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
Section/Paragraph: 210.19(A)(1) new exception
Added Revised Text
210.19 Conductors ? Minimum Ampacity and Size.
(A) Branch Circuits Not More Than 600 Volts.
....
Exception No. 1: If the assembly, including the overcurrent devices protecting the branch circuit(s), is listed for operation at 100 percent of its rating, the allowable ampacity of the branch-circuit conductors shall be permitted to be not less than the sum of the continuous load plus the noncontinuous load.
Exception No. 2: Grounded conductors that are not connected to an overcurrent device shall be permitted to be sized at 100 percent of the continuous and noncontinuous load.
Substantiation:
The new Exception No. 2 is because when the neutral is not connected to an OCPD it does not need to protect the device from heating due to 100% loading. The new exception is copied from the text in 215 which treats the same situation. The electrons don't know if they are in a feeder or branch circuit and act the same.
insert delete
Added Revised Text
210.19 Conductors ? Minimum Ampacity and Size.
(A) Branch Circuits Not More Than 600 Volts.
....
Exception No. 1: If the assembly, including the overcurrent devices protecting the branch circuit(s), is listed for operation at 100 percent of its rating, the allowable ampacity of the branch-circuit conductors shall be permitted to be not less than the sum of the continuous load plus the noncontinuous load.
Exception No. 2: Grounded conductors that are not connected to an overcurrent device shall be permitted to be sized at 100 percent of the continuous and noncontinuous load.
Substantiation:
The new Exception No. 2 is because when the neutral is not connected to an OCPD it does not need to protect the device from heating due to 100% loading. The new exception is copied from the text in 215 which treats the same situation. The electrons don't know if they are in a feeder or branch circuit and act the same.
insert delete