How is your inverter wired into your 120v circuit breaker panel
Did he add a new 30amp outlet for your shore cord to plug into?
Did he run new wire to the breaker box from the inverter
Or
Did he install a transfer switch between shore cord and the inverter
The inverter output side must be disconnected from the house wiring when using shore power
Do Not plug into shore power until you know it is safe to do so, you risk damage to the inverter even if it is turned off, if it is not physically/electrically disconnected from the breaker panel and shore power
