Tesla Powerwall 3 Commissioning SOP

Why this matters

The Powerwall 3 (PW3) consolidates inverter, battery, and gateway into a single 11.5 kW continuous / 13.5 kWh enclosure with up to four expansion packs (54 kWh total). Unlike PW2/Powerwall+, the PW3 has integrated MPPT (six DC inputs) so PV connects DC-direct to the unit. Botched commissioning leaves the customer without backup during the next outage, fails the AHJ inspection, and triggers Tesla warranty paperwork that takes weeks to clear. This SOP walks the start-to-finish commissioning sequence including PV-direct DC tie, backup-gateway-3 (BGW3) configuration, and Tesla One app activation.

Pre-arrival checklist

• Tesla One installer account active and credentialed for the customer site
• Tesla Energy permit-to-operate (PTO) confirmed if the utility has a permission-required interconnect (most do for batteries paralleled with PV)
• Customer has updated the Tesla mobile app to the current build
• Backup loads subpanel installed and labeled (whole-home or partial-home backup decided in design)
• Wi-Fi credentials available (PW3 will not commission without internet at first commission)
• AC and DC wire sizing verified against the design package

Pre-commissioning electrical checks

Before powering up, with all sources isolated:

1. Verify utility service voltage at the main panel (L1-L2-N). Should read nominal 240 V split-phase plus or minus 5 V. Service voltage outside that window will cause PW3 to log a grid-voltage fault on first sync.
2. Verify DC string Voc at each PV string with the PW3 DC disconnect OFF. PW3 accepts up to 600 V Voc per input; cold-day Voc must stay under this ceiling.
3. Confirm grounding electrode conductor (GEC) lands on the PW3 ground bar and the AC equipment ground bonds at the BGW3 per NEC 250.
4. Verify the BGW3 CT clamps are on the correct conductors: Service Mains CT on utility hot legs at the meter side, PW Backup CT on the load-side conductor feeding the backup loads.
5. Verify CT arrows point per the BGW3 install diagram - reversed CTs cause negative-production reporting and import/export billing errors but DO commission successfully, hiding the error.

Step 1 - Energize and reach Tesla One

Close the PW3 AC breaker at the main panel. Close the DC disconnects only if PV is to be commissioned today (PV-only commissioning can come later if the modules are not yet installed).

The PW3 indicator LED on the right side will sequence: solid red on first boot, blinking white during boot-up, solid green when standby. Allow 5 minutes from breaker close to standby.

Open the Tesla One app on a phone or tablet. Sign in with the installer account. Navigate to Commissioning - New Site, scan the site QR or enter the install address. The app discovers the PW3 over Bluetooth within 30 feet - confirm the gateway serial matches what is on the PW3 nameplate (located on the side under the Tesla logo).

If the unit does not advertise over Bluetooth, the PW3 firmware is below the commission-capable build. Factory reset via the side button (5-second hold) and let the unit pull current firmware over the customer's Wi-Fi.

Step 2 - System configuration in Tesla One

Walk through the Tesla One wizard:

• Site type: Residential / Commercial
• Service entrance rating: 100 A, 125 A, 150 A, 200 A, 320 A, 400 A (drives the CT scaling)
• Backup configuration: Whole Home (PW3 carries the entire load center) or Partial Home (only the backup subpanel is supported during outage)
• Number of PW3 units: confirm count if multiple are installed in parallel
• PV configuration: confirm each populated DC input with module count, module wattage, optimizer present yes/no

Whole-home backup requires the PW3 system kW continuous to exceed the customer's likely peak load. For homes with electric range, HVAC, EV charging, and pool pump, partial-home backup with non-essential breakers moved to a separate subpanel is the safer commission.

Step 3 - Grid code and utility profile

Select the utility grid code from the dropdown - the dropdown is populated based on Tesla's utility tariff library and matches the customer's utility account. Common ones:

• IEEE 1547-2018 default (most US utilities)
• Hawaii Source Requirements Document Category B (for HECO territory)
• CA Rule 21 (Southern California Edison, PG&E, SDG&E)

Wrong grid code at commissioning means the inverter does not ride through voltage and frequency anomalies the way the utility expects, and the utility's bi-directional meter may flag the site for forced disconnect. Verify with the utility's interconnection agreement document.

Step 4 - Commission PV inputs

In Tesla One, navigate to PV Inputs. The PW3 has six DC inputs (A1, A2, B1, B2, C1, C2) paired into three MPPTs. The app walks through each input:

• Confirm wired yes/no
• Confirm module string Voc within range
• Confirm Isc within range
• Tap "Energize Input" - the PW3 closes the DC contactor and begins MPPT tracking

A healthy input ramps to MPPT within 30 seconds and reports DC voltage and current in Tesla One. An input that energizes but produces zero current under sun = polarity reversal at the combiner. An input that fails to energize = open string or DC disconnect open.

After all PV inputs are energized, total system power should match expected based on irradiance and module wattage. A 7.5 kW array at noon clear-sky should produce 6.5 to 7.0 kW (real-world derate).

Step 5 - Backup test

Tesla One has a Backup Test button under System Functions. This simulates a utility loss:

• BGW3 opens the utility microgrid interconnect device (MID)
• PW3 takes over the backup load
• LED sequence shows green-blink (islanded operation)
• Customer's backup loads (lights, fridge, well pump, etc.) should stay energized

Run the test for 5 minutes minimum. Verify with the customer's helper inside the home that backed-up loads remained on without flicker. End the test and watch the re-sync: BGW3 phase-matches utility before re-closing, then the PW3 transitions to grid-parallel charge/discharge mode.

If the re-sync fails (more than 10 seconds of dwell after utility restore), the BGW3 phase reference is wrong. Open the BGW3 and verify the L1 and L2 sense wires landed correctly on the line-side terminals.

Step 6 - Customer handoff

Walk the customer through the Tesla app on their phone:

References

• Tesla Powerwall 3 Installation Manual, document number 1932981-XX
• Tesla Powerwall 3 Datasheet
• NEC 2023 Article 706 Energy Storage Systems
• NEC 2023 Article 690 Solar Photovoltaic Systems
• NEC 2023 Article 705 Interconnected Electric Power Production Sources
• IEEE 1547-2018 Standard for Interconnection and Interoperability of Distributed Energy Resources
• UL 9540 Standard for Energy Storage Systems and Equipment
• UL 1741 Supplement SB for grid-support utility-interactive inverters