16 of 20 - Backup Power Operation

 This guide proceeds under the assumption that the Inverter, Battery, Autotransformer (ATR), and Backup Loads Panel (BLP) have all been installed already with wires already ran and connected. If these steps have not been performed yet, please see one of the previous articles.  


The critical loads circuit breakers identified in Step 15 have now been relocated into the Backup Loads panel 

Wiring the Backup Loads Panel: 

  • L1 and L2 wires from the ATR should be landed in a 30A double-pull breaker in the BLP.  
  • The two neutral wires should be landed in the neutral bus bar of the BLP  
    • One from the MSP/sub panel landed in neutral bar 
    • One from the ATR neutral port  
  • The ground wire should be landed in the ground bar of the BLP 
  • Keep the 30A breaker in the off position until the system has been energized and tested 


How to Turn on the Backup Power System: 


  1. From the main screen, press Enter and then scroll down to Advanced Settings and press Enter 
  2. The password is (0010) press Down, Down, Up, and Enter 
  3. Scroll down to Backup Control and then press Enter 
  4. Backup ON/OFF should be highlighted, press Enter 
  5. Select ON and then press Enter - "Done!" will be displayed on the screen 
  6. The ATR and Backup Loads panel will now be energized 
    1. The ATR will make a soft humming sound - that is normal 
    2. On the screen in the bottom right corner there is a light bulb icon and an arrow going to it from the inverter 
      1. The arrow indicates how much power (kW) is being consumed by the BLP 
      2. Note: this is an instantaneous value and will change based on how much energy is being consumed 
  7. Test the AC voltage at the 30A breaker in the BLP 
    1. L1 to L2 should be 240V 
    2. L1 to Neutral should be 120V 
    3. L2 to Neutral should be 120V 
  8. If the voltages are correct, turn the breaker on as well as the other loads in the Backup Loads Panel 
  9. Note: the BLP will remain energized as long as the Backup Mode is ON and the inverter has not failed 
  10. Should the inverter fail, use the AC Bypass switch on the ATR to energize the BLP using grid power 


If the grid goes down (power goes out)... 

...the backup loads panel will remain energized by using the PV and battery power! 


Important! Keep BLP consumption to around 1 kW to last more than one day on PV and battery power - with a 10 kWh battery, the system has a bit over 9 hours of charge. If there is sun, the PV will add charge back to the battery. Monitor your system closely in the event of an outage! 



Victor is the author of this solution article.

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