When browsing for generators, it’s easy to become overwhelmed by the technical terms and abbreviations – W, V, kVA, AVR, PSW, etc. might all sound like Greek at first. But let’s look at what you really need to know in order to select the generator that is just right for you. It is, after all, not rocket science.
On the most basic level, a generator consists of an engine that drives an alternator, which in turn generates the power. The engine decides the maximum power output and the alternator decides the quality of the output. So far, so good. However, whilst maximum power output is a rather straightforward unit of measurement, the quality of the output is a bit more complex. This quality divides generators into three kinds: conventional brushless, automatic voltage regulation and inverter.
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Conventional brushless generators
Automatic voltage regulation generators
Power use examples
Generator comparison chart
TYPES OF GENERATORS
Conventional brushless generators
Sturdy and low-maintenance, brushless generators are generally the choice of tradesmen and builders. They represent a simple and dependable solution to powering tools and resistive loads such as kettles and lights. Since they do not regulate the voltage, they are not suitable for equipment sensitive to brownouts (partial blackouts) or power spikes. Furthermore, regardless of the load, they run at one speed only, making them less fuel-efficient than other models. Brushless generators are also relatively cheap, large, powerful and noisy.
Automatic voltage regulation generators
It’s all in the name; automatic voltage regulation (AVR) generators regulate the voltage output, ensuring that the supply of power is consistent, without brownouts or spikes. This makes them suitable for more sensitive appliances – but not necessarily for the most high-tech equipment that you own, because advanced electronics does not only ask for steady voltage; it also requires a smooth wave of power, a so-called pure sine wave. AVR generators put out a modified sine wave, which can overheat certain equipment and throw off the operation of appliances that rely on a pure sine wave, which is what the grid supplies, for timing (you can refer to the fact sheet on sine waves for more detailed information). The rule of thumb is that, the more advanced the technology, the higher the likelihood that it requires a pure sine wave. If you are uncertain about what your appliances require, it’s always best to consult the manufacturer, though.
There are AVR generators that do a great job of matching engine speed to required power output, and this naturally makes them considerably more fuel-efficient than brushless generators. Add their quiet operation and relatively high power output, and it’s easy to see why AVR generators are popular back-up units for homeowners.
Converting three-phase AC power to DC and then back to AC, the end product of inverter generators is power that is as smooth as what you get from the grid – sometimes even smoother. This means stable voltage and a pure sine wave that can run everything from roughly hewn pumps to sensitive computers.
Inverter generators build on the latest and most expensive technology and consequently come at a higher price than other designs, and they usually cannot put out as much power as brushless and AVR generators. But the inverter technology not only produces clean power; it also allows for very silent, compact and fuel-efficient units. This makes inverter generators popular with campers and 4WD enthusiasts.
POWER USE EXAMPLES
Now that you have a better idea of what kind of generator you want, it’s time to calculate how powerful it should be. The math involved is simple, but you need to remember that any appliance with a motor will draw significantly more power when starting (starting watts) than during normal running (running watts).
Establishing how powerful a generator you need asks for you to tally up the running watts of all loads except the one with the highest starting watts and then add those starting watts to the total. Sound tricky? It’s not. Just follow the proximate example below: adding all highlighted numbers gives you the required generator power.
|Load||Starting watts||Running watts|
|Camping fridge||600W (highest starting watts)||180W|
The total watts required will be 500 + 60 + 600 + 200 + 40 = 1400W
Note that the above wattages are proximate – you’ll need to check your individual appliances to ascertain what applies in your own circumstances – and that it’s always wise to select a generator that can put out a bit more power than you expect to use.
So, you know about the various types of generators and how much power you’ll need. What else should you keep in mind when purchasing a generator? There are a number of features that can make a real difference.
If you want to connect your generator to the mains board and run inbuilt appliances such as AC and stoves, you will need a transfer switch. This isolates the generator during blackouts, preventing overloading and backfeeding into the grid, something that otherwise poses a serious threat to neighbours and utility workers. Also, without a transfer switch, you will need to run leads from the generator to every load that you want to connect.
There are manual and automatic transfer switches, with the latter automatically detecting mains failures and starting and shutting down the generator as required without any interruption to the power supply.
Number of outlets
A 12V DC outlet is needed to charge vehicle batteries, and having multiple 240V AC outlets is important if you won’t be using a transfer switch.
A generator may offer a surge capacity to produce an exceptionally high power output for a short time in order to start demanding motor-driven loads. This is sometimes referred to as “max wattage”, with the standard operating wattage referred to as “continuous wattage”.
Should you want to use your generator for camping, pick a silent model or you might not be able to use it at all due to local regulations.
In Australia’s dry climate, any generator used for camping should feature a spark arrestor fore fire safety. [NOTE: add “Spark arrestor for fire safety” to all camping generator listings]
Fuel economy and tank capacity
Will you be running the generator for many hours straight? Pick one with a large fuel tank and good fuel economy. (Also, speaking of fuel, always run your generator dry before storing it away for long periods. This will prevent fuel from deteriorating and gumming up the generator.)
Generators usually need to cool down before you refuel them, and with a fuel gauge, you can avoid starting yours when it’s about to need refuelling. [NOTE: consider taking this point out if it risks losing sales of models without fuel gauge]
Regardless of other starting modes, you should be able to fall back on a recoil start (pull start) if all else fails.
Although most modern recoil starts require very little effort, starting the generator electronically with a key or button is certainly convenient.
For ultimate convenience, go for a generator with remote electric start, and you’ll be able to fire it up without even venturing outside.
Overload circuit breakers
Ensure that your generator features overload circuit breakers to protect connected appliances from damaging power spikes.
Automatic safety shutdown
With an automatic safety shutdown, your generator can be protected from damage due to low oil, high temperatures or other unsafe conditions.
If you plan on moving your generator around a lot, look for models that include wheels – preferably with pneumatic tyres – and sturdy handles.
GENERATOR COMPARISON CHART
Armed with this knowledge, you should now be able to make a smart choice when purchasing a generator. So, do the maths for your particular situation; make the call; and start looking forward to a future where power will always be within your reach.
Our generators are entirely focussed on functionality and economy, tailoring every design to the particular needs of different users. Conventional brushless generators are built to withstand the pressure on worksites, featuring reliable and high power output in a tough frame; AVR generators are quiet and fuel-efficient; and the inverter generators produce pure-sine-wave power to run the most sensitive loads, such as computers and other high-tech electronics. And there are capacities to suit all situations – from 1.5kVA lightweights right through to the 11.25kVa diesel workhorses.
CHART COMING SOON...
Whether it’s an active outdoors lifestyle, a building site with no mains power, or a power outage due to droughts, storms and floods, no one in the Western world needs generators more than Australians. However, since prices for some brands are prohibitive to the average person, many have gone without. Acknowledging this, a team of product developers set out to create a completely new line of generators and inverters in 2006. They handpicked the most recent technologies to meet the demanding Australian conditions and relied on online sales and word of mouth instead of spending big dollars on advertising and expensive shops. The result was a range of sturdy, dependable and affordable products to fit every Australian’s needs. Edisons was born.
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