Multi-Powerwall+ Systems

Installation Overview

For Powerwall+ systems with Backup Gateway 2, the Backup Gateway serves as both the Islanding Contactor and the Site Controller. It is connected to the first Expansion Powerwall+ unit and any Powerwall 2 AC units via 12V/CAN in a daisy chain.

Additional Powerwall 2 units may be connected in a side by side configuration as described in Side by Side Installations, or in a stacked configuration as described in Stacked Installations. An additional Expansion Powerwall+ can be connected to the last unit in the chain via CAN wiring (no 12V).

Maximum Distance Between Components

Distance to Measure Maximum Distance
Maximum communication cable length between each Powerwall+ 30 ft (10 m), units must be within line of sight, no obstructions
Total distance between the Backup Gateway 2 and the last Powerwall / Powerwall+ unit in the chain See Plan Distance Between Components

Install a Multi-Powerwall+ System

When installing a system with multiple Powerwall+ units, install each system component and connect the Backup Gateway 2 to the first Powerwall+ as it would be in a single Powerwall+ system.

  1. At each Powerwall+ unit solar assembly, find the part number for the solar assembly.
  2. If it is 1538000-35-x, proceed to step 3. If it is 1538000-25-x, unplug the 12V power harness on the solar assembly site controller to disconnect 12V power.
    Figure 1. Disconnect Site Controller 12V Connection
    Warning IconA warning icon, calling your attention to a possibly risky situation
    CAUTION
    If the 12V power is not disconnected from the Powerwall+, enumeration will be performed incorrectly during device setup.
  3. Remove the left side cover from the battery assembly of each Powerwall+.
    Informational PurposesAn informational icon, calling your attention
    Note
    It may be necessary to remove the small plastic insert at the bottom of the covers to help with removal. Turn the cover to one side and rest it against the Powerwall+ chassis.
  4. Using a T20 Torx bit, remove the wiring compartment covers from each Powerwall+.
  5. Run 4-conductor communication cable between the Powerwall+ units.
  6. At each Powerwall+:
    1. Remove the black heat shrink from the factory-installed battery whip.
    2. Remove and discard the terminating resistor.
    3. Strip the communication wire jacket about 3 inches and cut back the 12V and GND wires on either end of the communication wire. Cover the end of each exposed wire.
    4. Strip each CAN conductor 0.4 inches (10 mm), then insert the conductors into the green 4-pin connector on the end of the battery whip.
      Informational PurposesAn informational icon, calling your attention
      Note
      Cut back the drain wire at the first Powerwall+. This drain wire should be terminated at the second Powerwall+ battery assembly ground lug only.
      Figure 2. System Layout for Two Powerwall+ Units
      Figure 3. 12V/CAN Wiring for Two Powerwall+ Units
  7. To ground the drain wire:
    1. Strip the end of the equipment grounding conductor and wrap the communication drain wire around the grounding conductor lead.
    2. At the second Powerwall+, insert the drain wire and grounding conductor lead into the battery assembly chassis ground lug. The ground lug is identified with the following symbol:
    3. Tighten the screw in the ground lug to 4.5 Nm (40 lb-in).
    Informational PurposesAn informational icon, calling your attention
    Note
    There will be a drain wire grounded in each pair of units in the chain (Backup Gateway 2 and first Powerwall+, first Powerwall+ and second Powerwall+). For each pair of components, the drain wire is cut at the first component and grounded at the second.
  8. Close all wiring compartments and replace all covers as described in Step 6: Close the Wiring Compartments and Replace the Covers.