Tesla Powerwall 3 with Backup Gateway 2 Installation Manual AU v1.4

POWERWALL 3 SYSTEM DESIGN GUIDANCE

Design Considerations

Supported Configurations

Up to (4) Powerwall 3 units with (1) Backup Gateway 2, with or without AC-coupled solar

NOTE: Third party MLPE solutions, such as optimizers, are not compatible with Powerwall 3

Powerwall 3 is not compatible with the following:

• Neurio remote energy meters

• Other batteries (Powerwall 2 or third party batteries)

• Stacked units (Powerwall 3 must be mounted in a side-by-side configuration)

System Tie-in

Only Tesla devices are compatible with Powerwall; no third-party equipment in lieu of Backup Gateway 2

Backup systems must be one of the following:

• 230 V single phase service

  • 100 A or smaller service, or (in absence of a service rating) maximum 100 A of loads downstream of Backup Gateway 2

• 230 / 400 V three phase service

  • 80 A or smaller service, or (in absence of a service rating) maximum 80 A of loads downstream of Backup Gateway 2

  • Follow all local requirements for balancing the system equally across the available phases

NOTE: Regardless of the number of Powerwalls installed, only one phase (L1, L2, or L3) will provide backup during a grid outage.

A breaker is always utilized for Powerwall 3 tie in; see Install Powerwall and Generation Breakers in the Backup Gateway on page 59 for breaker size

NOTE: In line with relevant standards, Powerwall must be wired to support the maximum continuous current of the system.

Powerwall 3 must always be connected to the Home terminals downstream of the Backup Gateway 2

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 on page 20)

Any/all backup load centers are adequately protected with an overcurrent protection device

All three phase loads or solar must be excluded from the backup phase on the Home terminals

All single phase loads in the backup circuit must be sized appropriately for the configured power output of the Powerwall (see Install Powerwall and Generation Breakers in the Backup Gateway on page 59 for power output options)

Site and solar monitoring must be installed to capture overall power flow to/from the site, as well as all solar production

Powerwall and Backup Gateway 2 are rated for 10 kA of fault current.

Powerwall 3 Solar

Powerwall 3 has an integrated inverter and 3 MPPTs, with a maximum solar input of 20 kW DC.

NOTE: See AC-Coupled Solar System Sizing on page 24 for information about sizing AC-coupled solar with Powerwall 3.

System Sizing

The following resources explain how to size the Powerwall 3 system to meet customer expectations, as well as how to determine which loads can be included in the backup circuit and what to do with loads that cannot be included.

Backup Loads Supported per Powerwall Quantity

The largest load in the backup circuit is limited by the quantity of Powerwalls; the largest load/breaker size each Powerwall 3 can support is determined by the selected Powerwall 3 breaker size and configured power output (see Install Powerwall and Generation Breakers in the Backup Gateway on page 59)

See Appendix E: Installations with Multiple Powerwall 3 Units on page 129 for requirements for installing multiple Powerwall units.

AC Units and Large Motor Loads

Inrush current (largest instantaneous current draw when a motor starts) is limited to 185 A locked rotor amps (LRA) per Powerwall 3.

For air conditioner units, use locked rotor amps on equipment label as inrush current.

Design Options if motor locked rotor amps is greater than the number of Powerwall 3 units multiplied by 185A:

• Increase number of Powerwalls

• Relocate AC unit/motor load out of backup circuit

Example:

• Motor Load unit with 200 A locked rotor amps

• Required Powerwall(s): (2) Powerwall 3 units required, so that 200 A < 370 A

NOTE: Double-check that the AC breaker follows the Powerwall breaker sizing rules.

EV Charging

*Ensure the configured power output is great enough to support the charger(s) when off-grid; for instance, if Powerwall 3 has a configured power output of 5 kW, (2) Powerwall 3 units would be required to back up a Tesla vehicle charger.

Per the Vehicle Charging During Outage feature, the system will adjust the charging power during an outage to ensure Powerwall can continue to support the home without overloading Powerwall, and will only charge the vehicle when the percentage of charge is higher than the limit set by the customer.