215.15 Barriers.
Code Change Summary: A new code section requires barriers at specific feeder terminations.
In the 2023 NEC®, a new requirement for barriers was added to ensure that energized, uninsulated, ungrounded busbars and terminals won’t be inadvertently contacted when working on switchboards, switchgear, panelboards, or motor control centers that are supplied from the load end of feeder tap conductors or transformer secondary conductors covered in 240.21(C).
In a main circuit breaker (MCB) panelboard (supplied by a feeder tap, or transformer secondary conductors), when the MCB is opened, the busbar and branch circuit breakers are de-energized but the line terminals of the MCB are still live.
Running a steel fish tape into the panelboard can be dangerous if the fish tape curls up inside and finds its way to the line side of the MCB unless a barrier is installed to prevent this, or the power is shut off ahead of the feeder tap.
It’s easy to simply shut off one panelboard being serviced if it’s the only equipment supplied by a feeder. When multiple taps are made to a feeder to supply several pieces of equipment, in order to shut off one piece of equipment supplied from the load side of one of the taps, the electrician needs to start researching and coordinating a more involved temporary shutdown to perform the work.
As the number of taps made to the same feeder increases, so does the likelihood that the disconnect ahead of the feeder will never be shut off if someone needs to work in the equipment fed from the load side of one of those feeder taps.
Installing a barrier, to cover the line terminals that remain energized when the main overcurrent device is opened, helps to provide an extra measure of safety for those servicing load terminals in the same equipment.
Similar requirements for barriers are in Section 230.62(C), and 430.97(E).
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2023 NEC® edition of NFPA 70.
2020 Code Language:
This code language did not exist.
2023 Code Language:
N 215.15 Barriers. Barriers shall be placed such that no energized, uninsulated, ungrounded busbar or terminal is exposed to inadvertent contact by persons or maintenance equipment while servicing load terminations in panelboards, switchboards, switchgear, or motor control centers supplied by feeder taps in 240.21(B) or transformer secondary conductors in 240.21(C) when the disconnecting device, to which the tap conductors are terminated, is in the open position.