Solar PV system disconnect
Every PV system needs a readily accessible disconnect that separates it from all other wiring. It must be marked as the PV system disconnect, be lockable open, and use no more than 6 switches or sets of breakers.
What the code requires
A PV system must have a means to disconnect it from all other wiring, including other power systems, energy storage and premises wiring. The disconnect must be readily accessible. For circuits above 30 V where unqualified people can reach the disconnect, any enclosure door or cover that exposes live parts must be locked or need a tool to open.
The disconnect must show whether it is open or closed and be marked PV SYSTEM DISCONNECT or the equivalent. If its line and load terminals can be energized while it is open, a shock-hazard warning label under 110.21(B) is also required. It may consist of no more than 6 switches or sets of breakers, in one enclosure or a group, and one disconnect may serve the combined ac output of several inverters or ac modules.
It must be rated for the maximum circuit current, the available fault current and the voltage. It must open all PV conductors that are not solidly grounded at the same time and be lockable open under 110.25. Allowed types include a manual switch or breaker, certain connectors, a pull-out switch, a remote-controlled switch or breaker that opens on loss of control power, or a listed or approved device.
On the job
- Where all PV power is converted through interactive (grid-tied) inverters, an informational note in 690.13 gives a dedicated circuit breaker as an example of a single PV system disconnect.
- Breakers marked line and load may not be suitable for backfeeding.
- Inspectors check for the PV SYSTEM DISCONNECT marking and any required shock-hazard warning label.
What changed in 2023
The 2023 edition split 690.13(A) into (1) Readily Accessible and (2) Enclosure Doors and Covers with essentially the same requirements, and no longer limits the single disconnect for the combined ac output of inverters or ac modules to interactive systems.
Related sections
- NEC 690.12(C)
- NEC 690.15
- NEC 705.12: The 120% rule for solar and battery breakers
- NEC 705.20: Disconnects for solar and other power sources
- NEC 110.21(B): Requirements for field-applied warning labels
- NEC 110.25
Where this comes from
Send a photo. Get a real answer.
Text is fastest, and a photo quote is free. Call if it is urgent, if you smell something burning, or if a breaker will not reset.
CSLB #354550 · C-10 Electrical · Licensed since 1978 · $25,000 contractor's bond