How to Use Inverters
Written by: Helen McMenamin
From Fall 2018 issue of Connected to the Land
Things you need to know:
1. Inverters convert AC (Alternating Current) into DC (Direct Current) and back to AC
2. Power fluctuation is a thing of the past, you don't have to worry about surges and spikes with new technology
3. Inverter generators are very portable, small, lightweight and high tech when you are working or living off the grid.
Grid power has become so dependable and so available almost everywhere that we depend more and more on a good power supply. Whether we're out of reach of extension cords or off the grid, there are times we want or need power. Inverter generators are smaller, lighter, quieter and deliver cleaner power more conveniently than traditional generators.
Inverter generators use digital technology to convert alternating current (AC) to direct current (DC), and back to alternating current to deliver to the equipment receiving power. As the current changes, it takes on the same wave form as the current supplied by the electrical grid - what people in the field call "clean power." Two companies (Honda and Energizer) use a system called dual wave control to ensure both the amperage and the voltage delivered by the generator stay steady through changing power demands. This clean steady power is delivered to any electric-powered item, from the moment it's plugged into the generator.
SPLIT SECOND SPIKE
"When you put a big load on a traditional generator with an alternator, it bogs down just a little bit, for a second," says Chad Veenkamp of Energizer Generators. "It's not much of a change in the power supply - it drops down and then spikes up a for a moment - but it's enough to fry small equipment: computers, chips, any of those little controllers. It's enough to blow the circuits in a computer, tv or phone."
"The digital inverter maintains the clean power supply as the load changes, so sensitive circuits are safe."
Another big advantage of inverter generators is that they have an Eco setting that automatically adjusts the engine speed to match the power draw. That allows it to run more efficiently, and for longer on a tank of fuel - some run an air conditioner all night. Generating only the power needed for the actual load is also much quieter.
A quiet generator is especially important for RVs and cottages, where using a traditional generator running an air conditioning unit for several hours might disturb neighbours and wildlife. Some National Parks in the US have a maximum noise level for generators (68 Db at 50 feet from the unit), so it's worth checking the noise level of the generator before you buy.
According to Veenkamp, his company's generators make "a pleasant purr" from inside an RV or at a moderate distance from the machine. Their 3200 machine runs for over 15 hours on the ECO setting, and easily powers a typical RV's 13,500 BTU air conditioner.
A 2 kV machine is enough to run a fridge, lights, tv, phone and internet. A well pump might need a bigger generator or two machines, but it might be easier to handle, especially for a family or others who have to get water to animals without grid power. A small unit would allow you to use an electric pump for moving water from a creek to pasture water tanks.
HIGH TECH
Digital technology and efficient small engines allow for small, lightweight generators enclosed in casings to muffle engine noise. Some weigh less than 50 lb and more powerful models generally include wheels and handles.
They generally need little or no set-up - just add oil and gas (no fuel mixing except a fuel stabilizer if you don't expect to use the unit immediately) and start. Some larger machines have push button starts with remotes you can use from indoors. Most machines have power sockets that deliver power for different needs.
At present, inverter generators work on 120 volts, but makers are working on 240 volt models and dual voltage machines, to power even deep well pumps - invaluable in a power outage, if you have livestock that depend on pumped water.
The light weight and easy starting of inverter generators makes them very convenient for working with corded power tools, away from grid power. For situations where more power is needed, inverter generators can be used in parallel with a simple Y connection. The machines match their output, sharing the electrical draw and still supplying clean power.
Choosing an inverter generator is much like buying any other equipment you expect to last many years. Check the features, the warranty, and after purchase care. You want a reasonably close shop for warranty and other repair work.
Note: With slick casings, inverter generators can look like a home appliance, but they must not be used indoors or where exhaust can enter an enclosed area. All gas engine exhaust contains toxic carbon monoxide.