Inverters with automatic transfer switch

[Walaby]

Im in early stages on planning out the possibility of swapping my RV fridge for a residential fridge. I understand how to determine size of inverter, I understand the limitations of the batteries etc.

What Im struggling with in my mind, is where/how the 120 VAC output from inverter would be connected. I am looking at inverters with built in automatic transfer. So, if I want the inverter to power only my fridge, where do I connect the 120 VAC output to? The inverters Im looking at say they sense the lack of shore power and kick on (unless I switch it off of course), and then when shore power is connected, they stop.

Everything Im reading and seeing online is how to wire in a separate transfer switch. Not what Im hoping to do. Can I wire it to only run a single outlet when not connected to shore power? If so, how?

Thanks in advance

Mike

[FOWLERGK]

The Inverter has 120VAC inlet to power the unit plus provide a "pass through" to the 120VAC outlet on the inverter. You will need to wire the inverter 120VAC outlet to the trailer wall outlet the new
refrigerator will be plugged into. The inverter is also wired for 12 volts so when the inverter losses 120VAC, it will automatically convert the 12 volts to 120VAC and supply this to the refrigerator.

Simplified explanation however you will need to modify the trailer wiring to isolate the120VAC wire for the refrigerator. Basically the inverter will sit in-between the 120VAC wiring in theory.

[boyscout]

Im in early stages on planning out the possibility of swapping my RV fridge for a residential fridge. I understand how to determine size of inverter, I understand the limitations of the batteries etc.

What Im struggling with in my mind, is where/how the 120 VAC output from inverter would be connected. I am looking at inverters with built in automatic transfer. So, if I want the inverter to power only my fridge, where do I connect the 120 VAC output to? The inverters Im looking at say they sense the lack of shore power and kick on (unless I switch it off of course), and then when shore power is connected, they stop.

Everything Im reading and seeing online is how to wire in a separate transfer switch. Not what Im hoping to do. Can I wire it to only run a single outlet when not connected to shore power? If so, how?

Is it critical to you that the fridge be the only POSSIBLE 120V draw in the trailer? The other consumers of 120VAC in your trailer (air conditioning, TV, microwave, water heater on electric) consume little or none of it unless they are in use.

What if, when you're not connected to shore power, you simply didn't use the other 120V loads? You could even disable those things by turning off the breakers for their power supply, so they would draw no power at all and could not be accidentally used.

Your objective is likely that the fridge be the only significant load on inverter power, not that it be the only possible load, right?

You can accomplish the objective by connecting the inverter to supply power to the whole trailer as it would often be connected, but disable or not use the other loads rather than wire the trailer to isolate the fridge circuit. If some day you want to power a notebook or a low-powered fan on 120VAC you can do that. If your inverter and battery bank are sized for it you could do even more.

[traveldawg]

Another explanation...

An inverter with an internal transfer switch gets wired so inputs are from both a 120V circuit from shore power as well as 12v connection to your battery. The output goes to your refrigerator. It can be that simple.

When the inverter senses loss of shore power it switches from passing 120V straight through to inverting the battery's 12v to 120v.

Im in early stages on planning out the possibility of swapping my RV fridge for a residential fridge. I understand how to determine size of inverter, I understand the limitations of the batteries etc.

What Im struggling with in my mind, is where/how the 120 VAC output from inverter would be connected. I am looking at inverters with built in automatic transfer. So, if I want the inverter to power only my fridge, where do I connect the 120 VAC output to? The inverters Im looking at say they sense the lack of shore power and kick on (unless I switch it off of course), and then when shore power is connected, they stop.

Everything Im reading and seeing online is how to wire in a separate transfer switch. Not what Im hoping to do. Can I wire it to only run a single outlet when not connected to shore power? If so, how?

Thanks in advance

Mike

[Walaby]

Thanks for the responses. So, if Im understanding it correctly, to execute my single line vision I would

Take output from fuse box (fridge circuit breaker), run a wire to the inverter 120VAC input. Connect inverter to battery, and output from inverter to the plug for the fridge. In that manner, if 120V is detected coming IN to the inverter, it would pass through to the plug for the fridge. If not, then it draws 12 V and converts to feed fridge? Did I get that correct? Or do I go from the input side of the fridge breaker, to inverter, and back to input to fridge breaker. Im thinking the latter would keep the circuit breaker in play regardless of source of power.

boyscout. You do bring up a good point. I am probably overlooking the greater good and will ponder that as part of my thought process. I am just focused on the refrigerator, and not intending the project to expand to include additional batteries and solar, which could easily happen the more I think about it. At least not for this rig, at this time. Im not even sure I will do the fridge swap, as Im still mulling it.

Hopefully I captured what y'all are trying to relay to me.

Thanks

Mike

[gbkims]

Take output from fuse box (fridge circuit breaker), run a wire to the inverter 120VAC input. Connect inverter to battery, and output from inverter to the plug for the fridge. In that manner, if 120V is detected coming IN to the inverter, it would pass through to the plug for the fridge. If not, then it draws 12 V and converts to feed fridge? Did I get that correct?
Thanks
Mike

Yes sounds correct.
Here's cookinwitdiesel's post that has his diagram that shows how the rigs with residential frig inverters are usually wired.
https://www.mygrandrv.com/forum/show...in-the-trailer

[Walaby]

Thanks.. Think that confirms it, and also provides opportunity for the additional outlets

Thank you!

Mike