480.7(B) and 480.7(C) Battery System Disconnection.
Code Change Summary: New code sections provide additional requirements for DC disconnects serving stationary battery systems.
In the 2020 NEC®, a global movement is occurring to make sure that when a first responder arrives at a premises during an emergency call such as a building fire, they have an easy way to kill all power to the premises whether utility power, solar PV, energy storage or wind electric systems. Section 480.7 is no different.
For one-family and two-family dwellings in the 2020 NEC®, a disconnecting means or its remote control for a stationary battery system is required at a readily accessible location outside the building for emergency use. The disconnect shall be labeled “EMERGENCY DISCONNECT”.
According to 480.7(G)(1), a plaque or directory is also required at the service equipment or other approved location to tell the first responder all the locations of disconnecting means for other interconnected power production sources at the premises in accordance with 705.10.
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 2020 NEC® edition of NFPA 70.
2017 Code Language:
480.7 DC Disconnect Methods.
(A) Disconnecting Means. A disconnecting means shall be provided for all ungrounded conductors derived from a stationary battery system with a voltage over 60 volts dc. A disconnecting means shall be readily accessible and located within sight of the battery system.
2020 Code Language:
480.7 DC Disconnect Methods.
(A) Disconnecting Means. A disconnecting means shall be provided for all ungrounded conductors derived from a stationary battery system with a voltage over 60 volts dc. A disconnecting means shall be readily accessible and located within sight of the battery system.
N (B) Emergency Disconnect. For one-family and two-family dwellings, a disconnecting means or its remote control for a stationary battery system shall be located at a readily accessible location outside the building for emergency use. The disconnect shall be labeled “EMERGENCY DISCONNECT”.
N (C) Disconnection of Series Battery Circuits. Battery circuits exceeding 240 volts dc nominal between conductors or to ground and subject to field servicing shall have provisions to disconnect the series-connected strings into segments not exceeding 240 volts dc nominal for maintenance by qualified persons. Non-load-break bolted or plug-in disconnects shall be permitted.