Supported Configurations

• Up to (4) Powerwall 3 units with up to (3) Powerwall 3Expansion units can be installed with Backup Switch, Backup Gateway 2, or Gateway 3
  Note

  Backup Switch is not certified for installation in Canada; only install Powerwall 3 with Backup Gateway 2 or Gateway 3 in Canada.
• Powerwall 3 AC-coupled solar (Tesla Solar Inverter or third party solar inverters)
• Powerwall 3 is not yet compatible with the following:
  • Neurio remote energy meters (all metering must be performed by Backup Switch, Backup Gateway 2, Gateway 3, and/or Tesla Remote Energy Meter; see Metering Considerations for more information)
  • Other batteries (Powerwall 2, Powerwall+, or third party batteries)
  • Stacked units (Powerwall 3 must be mounted in a side-by-side configuration)
  • Non-backup systems

Powerwall 3 Solar

• Powerwall 3 has an integrated inverter and 6 MPPTs, with a maximum solar input of 20 kW DC.
• At least one MCI is required per string for the Powerwall 3 system to function properly. Where MCIs are required to meet Rapid Shutdown (RSD) requirements, see the Powerwall 3 installation manual for required MCIs depending on PV module.
  Warning

  Where it is allowable to install only (1) MCI per string, MCI-1 must be used. See the Powerwall 3 installation manual for more information.

System Tie-in

• Only Tesla devices are compatible with Powerwall; no third-party equipment in lieu of Backup Switch, Backup Gateway 2, or Gateway 3.
• Up to 200 A service with Form 2S meter socket when designing with Backup Switch.
• Backup systems must be 120/240 V single/split-phase service only.
• Backup Gateway / Gateway 3 should be installed with either a 200 A or smaller service or (in absence of a service rating) maximum 200 A of loads downstream of Backup Gateway 2 / Gateway 3 per NEC load calculations.
• No line-side or load-side taps for Backup Gateway 2 / Gateway 3 interconnection:
  • Line Side Tap: Connecting the Backup Gateway 2 / Gateway 3 to the line side of the main panel or service disconnect by tapping existing wiring is never allowed, according to NEC 230.82. Inherently, there are always loads downstream of the Backup Gateway 2 / Gateway 3; it is not permissible to interconnect loads to the supply side of the service disconnect (left figure). It is permissible for the Backup Gateway 2 / Gateway 3 to intercept the service feeders (right figure) because the main breaker in the Backup Gateway 2 / Gateway 3 becomes the main service disconnect.

    

  • Load Side Tap: Connecting the Backup Gateway 2 / Gateway 3 to the load side of the main panel or service disconnect by tapping via insulation-piercing connectors is non-standard practice and increases the possibility of issues and/or failed inspections. Connection to the Backup Gateway 2 / Gateway 3 must be a directly routed feed.

    

  Note

  When using the Backup Switch as the site relay, it is permissible to interconnect the generation panel via a tap because there are no loads downstream of the generation-only panel.

  

• Powerwall must not interact with (or must be completely isolated from) any other storage systems or generation sources not listed to UL 1741.
• An overcurrent protection device (OCPD) is always utilized for Powerwall 3 tie in (705.12).
  • The default required OCPD is 60 A; Powerwall 3 can be configured with a maximum current / power output, in which case one of the following breaker sizes is required

    Table 1. Maximum Continuous Current Options

    Maximum Continuous Current	Output (AC)	Breaker (Overcurrent Protection)
    48 A	11.5 kW (default)	60 A
    41.7 A	10 kW	60 A
    31.7 A	7.6 kW	40 A
    24 A	5.8 kW	35 A

  CAUTION

  If using a fuse as the Powerwall 3 overcurrent protection device, it must be a Class RK1 Fast Acting fuse. Use one of the following fuses or equivalent:

  Fuse Type	Manufacturer	Part Number
  60 A Fast-Acting Fuse, Class RK1, >= 250VAC, CLF	Littelfuse	KLNR60
  	Eaton / Bussmann	KTN-R-60
  	Mersen / Ferraz Shawmut	A2K60R
  40 A Fast-Acting Fuse, Class RK1, >= 250VAC, CLF	Littelfuse	KLNR40
  	Eaton / Bussmann	KTN-R-40
  	Mersen / Ferraz Shawmut	A2K40R
  35 A Fast-Acting Fuse, Class RK1, >= 250VAC, CLF	Littelfuse	KLNR35
  	Eaton / Bussmann	KTN-R-35
  	Mersen / Ferraz Shawmut	A2K35R

• Controlled sources such as Powerwall 3 can avoid the supply rules of NEC 705.12, including the 120% rule, when panel limits are used and backfeed is limited using software (also known as a Power Control System (705.13)), so no backfeed calculation is required. See Power Control System (PCS) Features for Powerwall Systems for more information.
• Recommend that total Powerwall supply is able to power the single largest automatic load in the backup circuit (see Backup Loads Supported per Powerwall Quantity).
• Any/all backup load centers abide by 705.12 or 705.13 and are adequately protected with an overcurrent protection device.
• A load center with generation and any others upstream must abide by 705.12 or 705.13.
• Site and solar monitoring must be installed to capture overall power flow to/from the site, as well as all solar production.
• Powerwall, Backup Gateway, and Backup Switch are rated for 10 kA of fault current. If potential fault current onsite is greater than 10 kA:
  • A J-class fuse upstream of the Backup Gateway 2 can be utilized to make the Backup Gateway 2 rated for 22 kA.
  • Backup Switch is rated for 22 kA when a minimum 22 kA main breaker is used in conjunction with the Backup Switch.
• Gateway 3 is rated for 25 kA of fault current when installed with an Eaton CSR or BWH main breaker, or 22 kA when installed with a Square D QO main breaker.
• Multiple Backup Gateways can be installed on a single site to accommodate sites with greater than 200A service equipment; see the Multiple Backup Gateways on a Single Site Application Note on Partner Portal.

Equipment Location

Powerwall is not installed in habitable locations.