Its 110volt I want to run it on a 12 volt inverter also plugged in to 110 service on a boat when I get to dock stations and turn on the 110 power supply I want it to Not FEED BACK INTO THE 12VOLT X110 VOLT INVERTER AND BURN IT OUT, OR WHATEVER WOULD HAPPEN IS SOME KIND OF ONE WAY DIODE NEEDED OR A INVERTER THAT DESIGNED TO DO THAT

 

Welcome to AAC!

Get a computer UPS (uninterruptible power supply).
The UPS is plugged into AC mains supply. It outputs 110-120VAC.
When there is no AC power it runs off its internal batteries.

 

I am trying to imagine how it is wired. You cant simply connect a socket to two AC sources.

If you want to do that you need either a manual switch or a relay to ensure that only one source is connected at a time.

 

I am trying to imagine how it is wired. You cant simply connect a socket to two AC sources.

If you want to do that you need either a manual switch or a relay to ensure that only one source is connected at a time.

Well if I plug the refrigerator into the inverter its on correct! Then unplug it from Inverter plug into 110 cord it works ,so I want to have it wires to both supply ,s but when I turn on the 110 it will not back feed into the 12volt inverter

 

A DPDT (double-pole double-throw) relay powered by the external 110 Vac would do what you want. There is a small air gap between the NC and NO contacts, so backfeeding should not happen. BUT . . .

A problem with this approach is phase. The inverter's AC output and the shore AC source will not be aligned in phase, so the refrigerator motor could receive a nasty transient when the incoming AC phase jumps 180 degrees (worst case) instantly. Not good.

A better way is two relays plus a control circuit to make sure the external AC is stable before changeover, and to build in a multi-second time gap between removing the inverter AC and connecting the shore AC (and vice versa). This is what an automatic changeover switch for whole-house home generators does. It is a big, expensive pain in the butt and worth every penny. Yours would be smaller and cheaper since the load is much smaller, you are not monitoring generator health, etc.

ak