Appendix E: Solar Inverter Rapid Shutdown

The Tesla Solar Inverter performs Rapid Shutdown in compliance with NEC 2017 and 2020 690.12(B)(2) and 690.12(B)(1) and UL1741 standards to reduce shock hazard for emergency responders.

When the Tesla Solar Inverter is used with Tesla MCIs, it qualifies as a Photovoltaic Rapid Shutdown System (PVRSS). The PVRSS is compatible with grid support functions and any limitations on the grid support functionality.

The Tesla MCIs are normally open solid-state switches (no moving parts). The Solar Inverter has a built-in exciter circuit that activates (closes) all MCIs via a 250 kHz AC frequency signal when the inverter is operating.

Figure 1. MCI-1 (left) and MCI-2 (right)

In compliance with PVRSS requirements, the conductors entering the Solar Inverter are controlled conductors.

Figure 2. Controlled Conductors in Solar Inverter System