National Electrical Code Tips: Article 690 -- Solar Photovoltaic Systems, Part
Part III of Article 690 provides the requirements for disconnecting means used with photovoltaic systems. It was heavily revised from the 2017 NEC.
- A means must be provided to disconnect the PV system from all wiring systems including power, energy storage, and utilization equipment [690.13]
- You must install the disconnecting means at a readily accessible location. This rule is primarily to help firefighters. If the system is above 30V and the disconnecting means is readily accessible to unqualified persons, any door or hinged cover that exposes live parts when open must be locked or require a key to openosure that can be open [690.13(A)].
- Each disconnect must be marked per the (rather wordy) requirements of 690.13(B).
- As with the rule for service disconnects in Article 230, you have a maximum of 6 disconnects (switches or set of circuit breakers mounted in a single enclosure or in a group of separate enclosures) allowed for each PV system.
- The rules for the type of disconnect have been completely rewritten with the 2020 NEC. There are five types of disconnecting means permitted, one of which is a pull-out switch with the required interrupting rating [690.13(E)].
- The PV system disconnecting means must simultaneously disconnect the PV system conductors that are not solidly grounded from all conductors of other wiring systems [690.13(E)].
- The PV disconnecting means or its remote operating device must be lockable [690.13(E)].
- Isolating devices or equipment disconnecting means shall be installed in circuits connected to equipment at a location within the equipment or within sight and within 3ft of the equipment [690.15(A)].
- An isolating device isn't required to have an interrupting rating [690.15(B)].
- Equipment disconnecting means shall have ratings sufficient for the maximum circuit current, available fault current, and voltage available at the terminals [690.15(C)].