your current plan
120v from breaker panel into the inverter,
inverter output goes to circuit
you want to be able to bypass the inverter
new plan NO switch to mess with
120v from breaker to NEW outlet box
inverter input gets a MALE plug, to use with NEW outlet for input
output from inverter gets NEW addon outlet box
circuit wire gets NEW male plug
evrything gets plugged together with inverter in the middle
if inverter dies
unplug from on both ends, plug circuit feed into outlet box from breaker panel
i can't make it any more simple explanation than that
you make the new inverter with transfer switch power pass thru
connect like it was a standalone inverter with outlets
if dies, you just unplug it , and plug things back together again
if this sounds confusing substitue female cord ends for outlet boxes
same thing
you need (2) females and (2) males a couple of short cords for the input and output of the inverter
the inverter (with cords) is the box in the middle of the circuit you are changing
you are sticking the 'box' in the circuit with out hard wiring it
you can unplug it and remove it at any time
remember if you hard wire it even with a DPDT switch
you will have wiring you have to disconnect IF you ever have to remove
this way it unplugs at a moments notice, for repair or replacement
it doesn't matter, no messing with disconnecting switch wires
its simple and its basically fool proof
This is the 120v in/ out pass thru, you still have 12v Battery wires
To disconnect at removal time, but if it dies just pull the fuses, when you move the plugs for the bypass option