Florida generator guide

How a Book-Sized Box Lets a 22kW Generator Run a 30kW House

Your neighbor has two AC units, an electric range, a pool pump, and a water heater — and somehow a standby generator smaller than the one the calculator swears he needs runs the whole place through a summer outage. He didn't buy a bigger unit. He added a device about the size of a paperback. It's called a smart management module, and its whole job is to make your appliances take turns so the generator never gets asked for more than it's got.

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Your house lies about how much power it needs

A sizing worksheet adds everything up like it all switches on in the same second. Both air conditioners. The range mid-dinner. The water heater. The pool pump. Stack those startup surges together and yes, you're staring at a 30kW machine.

But your house almost never does that. Two AC compressors rarely slam on at the exact same instant, and even if they try, they don't have to. That's the bet the module makes — and it's less of a bet than a rule it enforces. It watches the big loads and quietly makes sure the greedy ones don't all crowd the generator at once.

How a book-sized box knows the generator is sweating

The trick is frequency. Utility power holds a rock-steady 60 hertz, all day, forever. A generator's frequency rides on engine RPM, so the moment a big air conditioner kicks on and the engine bogs down under the strain, that number dips.

The module feels the dip. When it senses the generator straining, it drops its assigned load — your AC gets held at a red light it can't see, for about the length of a commercial break — then waves it back on once the coast is clear. It's a one-lane bridge with a flagger who never sleeps, standing between your two air conditioners so only one crosses at a time.

That frequency trick is also how it knows it's even on generator power. Flip a breaker off and back on during normal times and nothing happens — line power is a flat 60, so the module just sits there. It only starts directing traffic when it feels the wobble that means the grid is down and the generator is carrying the house.

Why this shrinks the generator you buy

Put each air conditioner on its own module and only one runs at a time. When the first compressor cycles off, the second one swaps in. The house feels the same — cool air the whole time — but the generator is only ever feeding one big surge instead of two.

That's the difference between two generator sizes. In Florida, where the air conditioning basically is the load, it's the whole ballgame. One system can juggle a dozen or so circuits and as many as four central AC units, ranking each one so your must-haves win and the water heater politely waits its turn. And because the modules talk to the generator over the power line itself, there's no extra control wiring snaking back to the unit, which keeps the install from ballooning.

The part the module can't fix

Here's the honest limit. A module rations who runs. It doesn't shrink how much any single thing draws. If your must-haves genuinely need to run shoulder-to-shoulder — say, a big AC and a well pump that both have to be live in the same moment — no amount of shedding conjures power that isn't there.

That's where a soft start comes in. It's a small add-on that softens an air conditioner's startup surge so the generator barely notices it kicking on. Pair one with a module and you can stretch a smaller unit even further. Or, in some houses, the math just says buy the next size up and skip the juggling.

Which path is actually cheaper for your house depends on your specific loads, your panel, and how many of them truly can't wait. That's not something a chart can tell you from a distance. Punch your address into the GENERasic price tool and you'll get one committed installed number for your exact home — the right-sized generator, the modules it needs, wired and running — instead of a range that moves every time you ask.

Common questions

Do I need one of these at every appliance, or just one for the whole house?

One module manages one load. If you want to shed your air conditioner, your water heater, and your range, each gets its own module. A single system can handle up to eight of them, ranked by priority, so the important stuff always wins and the rest wait their turn.

I've got a 22kW unit and just one heat pump. Do I even need a module?

Often no. Modules earn their keep when you've got several big 240-volt loads competing — two ACs, or an AC plus an electric range plus a water heater. With one heat pump on a properly sized 22kW unit, the generator may carry it fine on its own. The way to know is to actually add up what has to run at once for your house, not guess.

How does it know it's running on the generator and not just me flipping a breaker back on?

It reads the electrical frequency. Utility power is always a steady 60 hertz, so flipping a breaker during normal times does nothing — the module ignores it. A generator's frequency wobbles with engine load, and that wobble is the signal that tells the module the grid is down and it's time to start managing traffic.

Isn't a soft start on the AC better than one of these modules?

They solve different halves of the problem, and a lot of homes use both. A soft start shrinks the startup surge of one air conditioner so it's gentler on the generator. A module decides which loads get to run when things get tight. A soft start lowers the spike; the module manages the lineup. Depending on your loads, one, the other, or both together is the cheapest way to a smaller generator.

Why would my AC not come on at all after a module was installed?

That usually points to the module's internal contacts staying open — the switch that's supposed to close and pass power to the AC isn't closing, so the unit never gets its turn. Priority delays and long staggered restarts can also make it look dead when it's really just waiting. Either way it's a wiring or setup issue for the installer to check, not something you fix by yanking wires yourself.

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