Automatic Load Priority Switching box?

Inner Love

Senior Member
Joined
Mar 28, 2017
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282
Location
San Jose, CA
Until I can upgrade generators, I'm going to be using a 2000 watt Honda inverter generator for my heavy power loads. I will be using deep cycle house batteries and solar for base loads (under 500 watts total). With 1600 continuous generator watts, I can run anything, but not everything at once.

Is there such a thing as a 120v 15a Priority Load Switch? For example, it's a hot summer day and I'm running A/C directly from the generator, and I want to use my airfryer. I know that I will trip the breaker really quickly if I try to run both.

What I am looking for is an automatic primary - secondary switch that supports 100 watts of standby loads on the primary and automatically switches off the secondary when substantial load is detected on the primary.

For example, it's a hot summer day and I'm running A/C directly from the generator. I want to be able to prioritize everything else on the circuit that needs the full wattage from the generator for a short period of time. I want to program my time and temperature on my airfryer and keep the A/C running to the second I start the airfryer. Upon starting the airfryer frying, it automatically detects the surge current from the primary outlet (where the airfryer is plugged in) and shuts off the secondary outlet to prevent overloading. Then, after the airfryer is done; with say, a 5 minute delay - it automatically resets, kicking the secondary outlet (A/C) back on (I'll be using an A/C that saves it's set mode and temperature so it's automatically starts when power is restored).

Does this exist on the market?
 
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Think of something like an Automatic shore power transfer switch, but the plugs swapped, so that male plugs are female and vice versa.
 
Lot of cross concerns here, this is definitely not as simple as a transfer switch.

  • Multiple distinct inputs each with their own load ratings
  • Multiple distinct outputs each with a priority and load sensing
If you're really handy with Arduino, it is likely you could accomplish this with a set of relays and shunts/current sensors, and dividing up your electrical system in a complex and custom way.

The closest thing I can think of to handling this use case is the Victron Multiplus. It has a mode where it can supplement shore power with solar after the total system draw goes over a certain threshold. It would not shut devices off, but would rather use solar to augment the generator input.
 
Lot of cross concerns here, this is definitely not as simple as a transfer switch.

  • Multiple distinct inputs each with their own load ratings
  • Multiple distinct outputs each with a priority and load sensing
If you're really handy with Arduino, it is likely you could accomplish this with a set of relays and shunts/current sensors, and dividing up your electrical system in a complex and custom way.

The closest thing I can think of to handling this use case is the Victron Multiplus. It has a mode where it can supplement shore power with solar after the total system draw goes over a certain threshold. It would not shut devices off, but would rather use solar to augment the generator input.

Forget I ever mentioned the solar. I mentioned my solar baseload so I wouldn’t come across as a electrical noob.

What I am looking for is much simpler. An automatic 15amp 115v priority switch box, that I can plug into an extension cord. The box has one standard Type B plug and two standard Type B outlets, which I am labeling Outlet A and Outlet B. Outlet A is where my air fryer draws from. Outlet B is where my air conditioner draws from.

Outlet A & Outlet B stay on if total load stays under 15amps. When exceeding 15 amps across both Outlet A and Outlet B, the box automatically sheds the load on Outlet B (trips / switches off), to give Outlet A priority. Outlet B switches back on if Outlet B’s load is less than 4 amps OR the total load across Outlet A & Outlet B is less than 15 amps.

Instead of manually turning off the A/C to run my airfryer, the A/C shuts off from the outlet when I start my airfryer, and then switched back on when I’m done airfrying. I’ll be using an A/C unit that remembers its setting after a power cut so it will automatically turn on when power is restored.
 
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[I posted a reply to the wrong thread. If you want to read what I posted, see my March 12th, 2021 post in the thread ‘Looking Forward to Starlink’]
 
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what about a 2 way switch that when you toggle the switch you kill the power feed to the A/C and turn on the power to the air fryer.
or a little fancier universal RIB relays.
 
what about a 2 way switch that when you toggle the switch you kill the power feed to the A/C and turn on the power to the air fryer.
or a little fancier universal RIB relays.

I am looking for a more seamless experience than that, but that does work. I would just have to remember to toggle the switch before pressing Start.

Will look into universal RIB relays.
 

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