2025-02-26

Powerwall 3 Lockout/Tagout

Hazards: Arc flash and electrical shock.

Warning IconA warning icon, calling your attention to a possibly risky situation
Warning
This procedure is to be done before actively working on a Powerwall 3 to prevent arc flash and electrical shock hazard.

Tools and Equipment:

  • CAT 2 arc-rated long-sleeved shirt (tucked in) and arc-rated pants
  • Safety Glasses (ANSI Z87 rated)
  • Safety rated shoes with leather upper
  • Class 0 insulated electrical gloves with leather protectors or equivalent protectors (ANSI A4 cut resistant, ANSI A3 abrasion resistant, ASTM CAT2)
  • T20 Torx driver
  • Class IV Multimeter (rated for equipment voltage)
  • Proving Unit (Fluke PRV240 or equivalent)
  • Lockout/Tagout equipment:
    • Simple LOTOV: One person, One individually controlled lock, One tag with name and contact information, and breaker clamp
    • Complex LOTOV: A complex LOTOV is required for multiple energy sources and multiple disconnecting means.
    • Individually controlled locks & tags
    • Breaker clamps
    • Lock box or tree hasp
      • The LOTOV Lead will be the person designated by the service visit assignment.
      • The LOTOV Form is required for Tesla complex LOTOV.
      • All individuals working on equipment are required to be included in the LOTOV.
Overview:
Residential systems are highly variable, de-energization procedures may differ from site to site depending on the hardware the site has. Ensure you understand the site architecture and the required de-energization procedure before performing any work All steps of this procedure may not be applicable for all systems due to this variability, but any applicable steps should be performed. If you do not understand which steps are applicable please escalate to your manager for assistance.

Figures showing variations of systems containing a Powerwall 3. (non-exhaustive)

Warning IconA warning icon, calling your attention to a possibly risky situation
Warning

While de-energizing the system the proper PPE must be worn to protect against the electrical hazards that are present. Ensure you have the proper PPE and are wearing it correctly.

  1. Turn off the system via the setup app and ensure the app reflects that it's been turned off.
  2. Flip the battery enable switch to the “OFF” position and place a lock and tag as shown in the picture.
  3. If present, turn off the PV switch/DC disconnect.
    Informational PurposesAn informational icon, calling your attention
    Note
    This may not be present on every system. Systems with MCIs will be disconnected upon shutdown of the system through the app.
  4. Apply a LOTO to the PV switch if available.
  5. Turn off the Powerwall breaker in the load center directly upstream, where powerwall connects to the home electrical. Some setups may have a backup gateway serving as the load center, if this is the case turn off the powerwall breaker in the gateway.
  6. Apply breaker clasp and LOTO.
  7. Wait 5 minutes to allow voltage to drop to safe level.
  8. Inspect and put on Class 0 insulated electrical gloves with leather protectors.
    Informational PurposesAn informational icon, calling your attention
    Note
    Be sure to wear required PPE prior to working on the PW3. Make sure this is done until the PW3 is checked for dead and verified to have 0 voltage.
  9. Unscrew the six fascia fasteners using a Torx T20 driver, remove the front cover, and set it aside away from the battery. Support the cover as screws are removed so it does not drop and break.
  10. Prepare a multimeter (rated for equipment voltage) with leads to measure AC and DC voltage. Using a proving unit or another known live source ensure the multimeter is operational and reads the correct value. If multimeter gives incorrect readings do not continue, substitute the meter for another one and repeat the check. Only move forward if the multimeter is functioning correctly.
  11. Using a multimeter to probe in the AC terminals, make sure AC voltage is within safe level. Check line to line, line to neutral, line to ground. Readings should be very close to 0V.
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning

    If seeing live voltage, go back to previous steps to make sure main breaker and shutdown switch are off. If still seeing high voltage, reach out to manager. Ensure you have the proper PPE and are wearing it correctly.

  12. Use a multimeter to test for DC voltage in the PV terminal. Test each positive lead with respect to it's negative, as well as each wire to ground. Voltage should be close to 0.
    Warning IconA warning icon, calling your attention to a possibly risky situation
    Warning

    If seeing live voltage, go back to previous steps to make sure main breaker and shutdown switch are off. If still seeing high voltage, reach out to manager. Ensure you have the proper PPE and are wearing it correctly.

  13. Test the AC terminals for DC voltage to ensure there is no DC backfeed. The reading should be 0V. If there is a non-zero reading do not proceed and escalate to your supervisor.
  14. Using a proving unit or known live source, measure voltage again with the multimeter to ensure you get accurate values. If the multimeter does not show accurate readings substitute for another multimeter and repeat the checking for dead steps.
    Informational PurposesAn informational icon, calling your attention
    Note
    Be sure to check both AC and DC voltage modes.