Powerwall & Gateway Design & Install guide

1. Site Planning and Preparation

• Environmental Considerations:

  • Select an installation site that meets Tesla's environmental guidelines: Powerwall should operate within a temperature range of -4°F to 122°F (-20°C to 50°C).

  • Indoor installation is recommended, especially in climates with extreme temperatures. If outdoors, install under a sheltered area to avoid direct exposure to rain or snow.

• Clearance Requirements:

  • Maintain at least the minimum clearance on each side of Powerwall for ventilation and access. See guide below for clearances
    
    

  • Minimum lateral wall space: 32 inches (808 mm)

  • Minimum clearance from left side: 4 inches (100 mm)

  • Minimum clearance from right side: 4 inches (100 mm)

  • Minimum clearance above Powerwall: 2 inches (50 mm)

  • Minimum clearance below Powerwall: 0.8 inches (20 mm)

  • Minimum clearance between side-by-side Powerwalls: 4 inches (100 mm) 1

  • Minimum clearance in front of Powerwall: 12 inches (300 mm) 2

  • Maximum height above ground: 45 inches (1140 mm) to bottom of unit feet3,4

  • Maximum slope: +/– 2° side-to-side

• • Ensure sufficient space for electrical wiring and conduit runs to prevent overcrowding of cables.

• Pre-Installation Checks:

  • Inspect the wall where Powerwall will be mounted to ensure it can support the weight (over 250 lbs or 113 kg).

  • Confirm adequate access to both the main electrical service panel and any required secondary panels, especially if working with multiple Powerwalls or PV connections.

Design Preferences
Here are the preferences that Design should consider when creating the deliverables.

• Taps are allow with the Backup switch 

  • Must check utility company to verify its allowed with them. Refer to this site to see what utility companies they are allowed in.

• No Tapping Policy with the Gateway 3 

  • Tesla does not allow the Gateway to be interconnected via a tap using conductor-piercing means. The feed to the Gateway must be dedicated.

• Mounting preferences

  • 1st Choice - Wall Mounting

    • Choose a wall capable of supporting the full weight of Powerwall, with one of the following characteristics: wood studs at regular intervals, plywood sheeting of sufficient thickness, solid concrete or masonry, or metal studs of sufficient gauge. 

• 2nd Choice - Floor Mounting

  • Choose a level surface adjacent to a wall space that meets all the requirements for wall mounting described above. Make sure the area is isolated from hazards that may damage the unit, such as vehicle traffic or flooding. 

• 3rd Choice - Free Stand Mounting

  • Use it when the Free-standing is the only option for Powerwall Installation (No Wall/Floor Mount Available) or when customer is only interested in Free-Standing Powerwall. 

• Cable Entry

  • Determine whether cables will be routed into Powerwall from the side or from the back of the unit. With side cable entry, a conduit fitting or cable gland must be used to seal the entry into the wiring compartment. With back cable entry, a wire cover should be used to seal the entry into the wiring compartment. 

  • Powerwall Location Limitations

    • Powerwall cannot be installed on any habitable spaces. This table includes the approved interior and exterior requirements for mounting Powerwalls. 

    • If Powerwall is mounted on a wall with studs spaced 24 in (610 mm) apart, cable entry from the back of Powerwall may be blocked. 

2. Mounting the Powerwall

• Installing the Wall Bracket:

  • Locate wall studs or secure points in masonry to install the bracket firmly.

  • Use a level to position the bracket accurately. Drill anchor holes if required, and secure the bracket using bolts capable of bearing Powerwall’s weight.

  • Confirm the bracket is horizontal and level to avoid future shifting.

• Hanging Powerwall on the Bracket:

  • With a second person, lift Powerwall carefully and place it onto the bracket. Ensure that Powerwall hooks securely onto the bracket to avoid any tilting or imbalance.

  • After positioning, check stability by gently rocking Powerwall; it should not move or tilt.

  • Secure Powerwall with any additional screws or bolts as directed by Tesla to enhance mounting stability.

3. Electrical

**Note: The Backup Gateway is service entrance rated, and can be located between the service entrance and the main electrical panel.  

• Selecting Gateway Mounting Location:

  • Position Gateway near the main breaker panel to minimize the need for extensive wiring runs.

  • Keep Gateway in a well-ventilated area, avoiding exposure to moisture or extreme temperatures, as this could affect Gateway performance.

• Wiring and Grounding the Gateway:

  • Ensure Gateway is properly grounded according to electrical codes by connecting the grounding wire to the main service grounding bar.

  • Use strain reliefs on all wire entries to prevent wear on cables.

• Breaker Configuration:

  • Install a breaker between the Gateway and the main service panel. The breaker rating should match Tesla’s specifications for Gateway (e.g., typically 30A or 50A depending on configuration).

  • Backfeed capacity: Main Breaker + Solar + Powerwall(s) must be less than 120% of panel bus rating (705.12.b.2.3.b), sum of the handle ratings in the panel must be less than the panel rating (705.12.B.2.3.c), or some generation must be landed in a separate load center to comply with 705.12.

Tesla's Interconnection Strategies.

**NOTE with Electrical changes.

If we are trying to change the relocated loads that the powerwalls are covering. There are some things to keep in mind.

Appliance Inrush (Electrical stuff)

When the AC unit (or what has higher inrush current, we may need more than one Powerwall to backup the load. 

Inrush current is the largest instantaneous current draw when a motor starts.

Newer Powerwall units, with part number 2012170-05-e, 3012170-xx-b, and later, can support 108A of inrush current.

Older Powerwall units are limited to 28A of inrush current.

For example: The inrush current of a 50-amp AC unit is 86A. To backup up this load, only one newer Powerwall is required.Other Options for Large AC Units: Soft-Starter device and AC load shedding

Here is a list of what the number of powerwalls can handle what appliances.

Partial load back up.
For partial-home backup installations where the Backup Gateway is installed on the load side of the main breaker and supplies power to only a subset of the loads, follow these steps:

• The pre-wired voltage taps in the Backup Gateway are correctly positioned for this configuration and do not need to be relocated. 

• Remove the two CTs from the Backup Gateway. 

• Install the CTs on the corresponding power wires in the main panel, between the utility meter and before any loads. 

• If solar equipment is present, install an additional CT on the solar L1 line in the electrical panel. 

INSTALLATION NOTE: If a panel component (such as a bus bar) prevents placement of both CTs between the utility meter and the main breaker, one CT can be placed on each side of the main breaker. If this is done, first ensure that the main breaker L1 and L2 terminals are not reversed on the load side. If the terminals are reversed, ensure that the line-side and load-side CTs are placed on the appropriate line.

PCS (Power Conversion System) : Is a device that converts electrical energy from one form to another
Explaination: PCS acts as a bridge between the power grid and storage elements, such as large banks of batteries. It converts direct current (DC) to alternating current (AC) for transmission, and vice versa. 

Application: To avoid main breaker downsizes, you can use PCS to set conductor export limit. It limits Powerwall output to a set value (as low as 0). 

A dedicated pair of CT's must be placed in location where Powerwall output is limited. (Face the CT's labels toward the grid, and set this pair as "Conductors" in the commissioning.)

PCS Common application: Upstream of Gateway, set conductor export limit so that Powerwall backfeed does not flow to any panel upstream of the Gateway. When the combined PV+PW backfeed violates the 120% rule at the MSP – use PCS to limit PW output to the Main Service panel to comply with 120% rule. 

Avoids the following due to Powerwall backfeed:

MPU’s

MBD’s

Load Relocation for 705.12(B)(2)(3)(c)

Note: You may need to confirm with the local utility/AHJ that they accept the function PCS prior to usage.

CONSIDERATIONS

4. Connecting AC Circuits

• AC Voltage Verification:

  • Before making any connections, measure AC voltage on the main panel to confirm voltage levels and phase (120/240V) to avoid incompatibility.

• Running AC Wiring:

  • Use conduit as required for safe, organized wiring. Connect L1, L2, and Neutral lines from Powerwall to the main panel, ensuring tight and secure connections at each terminal.

  • Double-check that L1, L2, and Neutral are properly aligned to prevent phase mismatches or electrical issues.

  • Breakers in the Backup Gateway has a breaker hold down kit.  

• Grounding Verification:

  • Use a voltmeter to test continuity between the ground terminal on Powerwall and the main panel to ensure the ground connection is effective.

  • Tighten all ground screws to proper torque specs, verifying there is no slack.

5. Solar PV Connections (if applicable)

• Shutting Down PV System:

  • Turn off the PV system completely before working on any wiring. Confirm with a voltmeter that no current is present in PV leads.

• Connecting PV Input Terminals:

  • Wire PV leads into either the Gateway or directly to Powerwall, depending on system configuration. Check that PV connectors match L1, L2, and Neutral on Powerwall’s input.

  • Securely fasten all PV terminals and inspect for exposed wiring that could pose a hazard.

• Inverter Compatibility Check:

  • Adjust settings on the inverter to ensure it works with Powerwall if necessary (e.g., changing operating modes or enabling battery support).

6. Current Transformer (CT) Installation and Metering

• Placing CTs on Conductors:

  • Snap CTs around the appropriate conductors. Make sure that the arrow on each CT points toward the loads to accurately measure current flow.

• Metering for Phase Consistency:

  • Use a voltmeter to confirm voltage readings are consistent across phases. Between two points on the same phase, voltage should read 0 volts; between two different phases, it should read around 240 volts.

  • If readings are inconsistent, review connections to correct any phase mismatches.

• Connecting Meter Wires:

  • Secure meter wires to their respective terminals in the Gateway, labeling each wire if needed for clarity.

Things to check during audit and Key points

• Conduit punch ins

  • Is it in a acceptable location

• Drain wire

  • Is it trimmed back at the gateway 

  • Is it wrapped aroung the EGC 

• Do we have the proper clearances around the PW/Gateway?

• Fabricate the communication connectors at the Gateway and Powerwall. Ensure that the wiring matches on both ends.

• Install the connector with terminating resistor in the OUT port of the Powerwall.

• Connect the Powerwall harness to the AC conductors with Wago lever nuts.

• Ensure all connections are securely seated.

• Create a drip loop for conductors inside the wiring compartment.

7. Final System Commissioning and Testing

• Sealing and Securing Panels:

  • Close and fasten all compartments on Powerwall and Gateway, ensuring a tight fit to prevent dust or moisture ingress.

  • Double-check all wiring is properly routed and that any protective covers are installed over electrical connections.

• Powering Up the System:

  • Begin by powering on the Gateway, then Powerwall, and finally, any PV systems.

  • Check the system status indicators on Gateway and Powerwall for error lights or alerts. Refer to Tesla’s troubleshooting guide if needed.

• Software Configuration via Installer Toolkit:

  • Open the Installer Toolkit app to configure Powerwall. Set up parameters such as backup reserve, battery charging preferences, and other settings.

  • Perform a calibration check through the app to ensure the system is reading and processing data correctly.

• Verifying Energy Flow:

  • Observe power flow from the main panel, solar PV, and battery through the app. Verify all components are functioning correctly and that data on production, consumption, and backup reserve is accurate.

Powerwall 3 Sleep State Overview

Starting with software version 24.12, Powerwall 3 enters a Sleep state when these conditions are met for over 10 minutes:

• The Powerwall 3 Enable switch is ON

• The system in Tesla One is OFF (stopped)

The Sleep state prevents the Powerwall 3 from fully depleting its State of Energy (SOE), which would make it unrecoverable.

Every two hours, Powerwall 3 will automatically wake up to check its status:

• If the system in Tesla One is ON, Powerwall 3 will stay awake and return to normal operation.

• If the system is still OFF, Powerwall 3 will re-enter the Sleep state after 10 minutes.

Note: Powerwall 3 may enter the Sleep state during installation; the only exception to this rule is when the Powerwall software is updating - in this case Powerwall 3 will not go to sleep. See Waking Powerwall 3 from Sleep State to manually wake a Powerwall 3 that has gone to sleep during installation.

Important Note: If the installer attempts to exit Tesla One with the Powerwall 3 switch ON and the system OFF, an alert will remind the installer to either start the system or turn the Powerwall 3 switch OFF.

For all Powerwall 3 systems, the logo LED is the primary method of confirming Powerwall 3 is in the Sleep state: 

Note: For Powerwall 3 systems installed with Backup Switch or Gateway 3, the Tesla Asset Controller (TACO) LEDs will also be OFF to indicate Powerwall 3 is asleep.

Waking Powerwall 3 from Sleep State

To manually wake Powerwall 3, toggle the Powerwall 3 Enable switch OFF, wait three seconds, then toggle ON. Powerwall 3 will boot up in about 90 seconds, and all LEDs will turn on.

Note: As noted above, Powerwall 3 will automatically wake every two hours; if the system has been started, it will boot up and return to normal operation. This automatic wake-up cycle ensures Powerwall 3 can automatically recover from 0% SOE conditions, such as a long-duration grid outage.

Minimum Clearances photo example