Appendix D: Solar Rapid Shutdown

Powerwall 3 performs Rapid Shutdown in compliance with NEC 690.12(B)(2) and 690.12(B)(1) and UL1741 standards to reduce shock hazard for emergency responders.

When Powerwall 3 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). Powerwall 3 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. Tesla MCI-1 (left) and MCI-2 (right)

In compliance with PVRSS requirements, the conductors entering the solar assembly are controlled conductors.

Figure 2. Controlled Conductors in Powerwall 3 System with Backup Gateway 2