Inverter to main panel on breaker

bearqstbearqst Registered Users Posts: 5 ✭✭
Connecting my Magnum 4024 PAE Inverter to our main panel. I currently have a 7000 W genny connected to the main panel's source and would like to leave it available as a back up.

I've heard that I could connect the Inverter to a 30amp breaker and the panel would recognize it as a source.

This would give me a breaker I could use to disconnect the inverter/batteries as the source for the house and then use the 7000w unit as it is. My thoughts are this would allow me to have a back up option if/when I need to shut off the inverter/batteries for service and still have full power to the house.

I know I'd have to be careful not to have both sources hot at the same time, but that's a no brainer as the current one is only operable when the genny is running and it is connected to the 120 port.

Is this doable


  • BB.BB. Super Moderators, Administrators Posts: 32,088 admin
    edited August 2018 #2
    Welcome to the forum Bearqst.

    Generally, for an AC inverter with AC input, you would connect:

    Genset AC -> Inverter Genset AC input -> Main AC panel (if your inverter+genset will run everything)

    Or, if you have a main panel (for genset or AC utility power) and a second "protected panel" that will only be powered by the AC inverter:

    Genset => main panel (with major non-inverter loads) => genset input of AC inverter => protected panel (just the loads you want to run from AC inverter)

    You really do not want to put the Genset AC output and Inverter AC output on a 2nd breaker into one main panel. Generally it is illegal for code, and more important, it makes for easy mistakes that can ruin equipment and perhaps even start a fire (both Genset breaker + AC inverter breakers turned on--Two AC outputs tied together is almost always bad news).

    There are transfer switches with "lockouts" (prevent both AC outputs turned on at same time, as well as various types of automatic and manual transfer switches. First is a manual lockout transfer switch, second is a simple time delayed relay, third is a multi-branch transfer switch.

    Your Magnum inverter has an AC Utility/Genset input with automatic transfer switch... About the only "extra transfer switch" you may want to install is one that moves the AC input to the protected panel from Genset or AC inverter--So you can take the inverter out of service for maintenance and let the genset power the protected panel directly.

    Assuming I understood your questions correctly.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bearqstbearqst Registered Users Posts: 5 ✭✭
    Thanks BB, don't know why I didn't think of a transfer switch, we use one in our on grid home. The Midnigh manual switch would work fine.
  • MrM1MrM1 Registered Users Posts: 487 ✭✭✭✭
    edited August 2018 #4
    I can vouch for the Reliance Controls system. I have the 10 circuit one. It allows for a circuit by circuit transfer between sources (genny and inverter OR inverter and grid OR grid and genny as examples for input power sources). If manual is what u need I find the Reliance Controls systems are excellent. And allow for ultimate control.  It's not an all or nothing proposition like a single whole panel transfer switch. You can decide based on need and power availability if you want say just the fridge on genny and all lights and fans on battery, or if there is full sun and available solar u can the switch fridge over to battery too. Very versatile. It also eliminates the need for a separate dedicated stand alone secondary inverter load panel  
    REC TwinPeak 2 285W 3S-3P 2.6kW-STC / 1.9kW-NMOT Array / MN Solar Classic 150 / 2017 Conext SW 4024 Inverter latest firmware / OB PSX-240 Autotransfomer for load balancing / Trojan L16H-AC 435Ah bank 4S connected to Inverter with 7' of 4/0 cable / 24 volt system / Grid-Assist or Backup Solar Generator System Powering 3200Whs Daily / System went Online Oct 2017 / System, Pics and Discussion
  • bearqstbearqst Registered Users Posts: 5 ✭✭
    It looks handy, our current one just does the whole house and is manual, but works great during these Alaskan winters when the power grid goes down. Our off grid and soon to be full time residence is where I need to install. Think I'll be going with the Midnight Sun Manual Transfer unit. I really only want it as a back up for maintenance and shouldn't need it more than once or twice a year.

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