Power on demand is something we take for granted, but for those times when a three-pin-plug isn’t handy or the lines are down, a portable generator can be a lifesaver.
Living rurally means putting up with more power cuts, whether it is from a natural disaster or a man-made incident. Rural life may also require you to work far away from your normal power supply, this is where a portable generator can be your only electricity source.
Living rurally means putting up with more power cuts, whether it is from a natural disaster or a man-made incident. Rural life may also require you to work far away from your normal power supply, this is where a portable generator can be your only electricity source.
Framed generators are basic and economical to purchase, ideally suited for the farm, lifestyle block or construction sites.Then there are smaller, near-silent systems available for use in your caravan or on your boat, perfect for getting power but still keeping the peace and quiet in populated areas.
Choosing the right machine
Generators come in a huge range of sizes, from small portable generators to large, permanent fixtures that can be used as a temporary power back-up to your home or milking shed.
Choosing the right machine
Generators come in a huge range of sizes, from small portable generators to large, permanent fixtures that can be used as a temporary power back-up to your home or milking shed.
Here we are going to concentrate on portable generators and in this case, size matters. The size of generator you need will depend on the power you intend to use, but there is a trick to working out just how many watts/amps you will be required to supply.
For example, if you want to use a portable generator so you can power an air compressor on a remote site, you will need to check the watts/amps that the compressor requires to run (which will usually be indicated by a tag on the compressor).
However, on start-up many types of electric motors will draw up to four times the watts/amps that is specified to run them. So if your average compressor requires 1500watts to run on, you will most likely need an additional 4500watts to get the electric motor started (this will vary from brand to brand). For this reason, it is very important to consult your local generator specialist for advice and stick with a well known brand.
Resistive loads such as lights, heater elements, radios and computers usually don't require extra power to start, so it will pay to be specific when talking to the experts about a portable generator and its uses, is it could save you money.
When you go to buy a portable generator, the salesperson should take care to add up the total wattage you think you may require, then do a series of mathematical calculations to work out which generator size is best for you depending on the application.
If you buy a generator that is too small to run the appliance or power tool you want to use, you risk killing your generator and the equipment you have plugged into it. Quality generators will have an AC overload protection that will cut the power if there is an overload, but there are some models on the market that only have a “thermal overload” that cuts out when the generator overheats, often too late to prevent any damage.
“A miscalculation in the size of generator required is the most common mistake people make when looking to buy a generator,” says Steve Thompson of Power & Marine. “Keep an eye on the power ratings and don’t overload your generator. If it does get overloaded and it only has thermal protection, you’re in trouble. If you have a 1500 watt fridge and buy a 1500 watt generator it just won’t do the job.”
From small to large
The smallest portable generator is perfect for use on a boat or in a caravan and should be compact, fully enclosed, insulated and very quiet – the running noise should be about as loud as someone talking.
At the higher output end, you can get a large, framed, portable generator, usually up to 8kva. These will be louder than the smaller units and have a robust, rough and ready appearance. Use caution when thinking about running welding equipment from a generator, and always seek professional advice. Steve says a welder is one of the most challenging pieces of equipment to run off a generator.
“It’s probably the nastiest thing you can use a portable generator for. A welder uses massive amounts of current draw on start-up, and when you think about welding, you’re starting up all the time - every time you strike the a weld, that’s a huge kick of power that only a larger top quality generator can handle.”
Do you need an inverter?
Some types of portable generator utilise inverter technology. This useful addition helps to give you a smooth power output or “clean power” so you can run sensitive machinery off it, like a computer laptop or a GPS unit.
An inverter takes the raw power produced by the generator, passes it through a microprocessor that takes it from AC to DC then inverts it back so you end up with a continuous supply of power that won’t interfere with the use of something as sensitive as a computer, a video camera or other types of digital equipment.
Ask for figures on the power quality with these generators and compare accordingly if you have sensitive equipment to run.
Nifty extras
Some generators start with a pull-start like you use to start a lawn mower. Larger models come with key start to make start-up as easy as possible. Pull start backup should be standard just in case of a flat battery.
Others are very quiet, have low emissions, and can be very fuel-efficient. This comes down the quality of the brand.
While many portable generators are light enough for one person to throw on the back of a truck, others can be a bit more civilized and come on a wheeled frame so you can roll it around easily.
Buyer tips
• Always purchase a generator that has a full range of spare parts available. You never know when you might need some emergency power.
• Get the generator serviced on a regular basis. Check with your retailer for service intervals.
• Purchase a generator with slightly more power than you require. It will save you money in the long run, and leaves an allowance for future appliance upgrades.
• Check power requirements with a competent, servicing dealer. Accuracy counts!
• The general rule – there is no substitute for quality. Check the warranty period, terms and conditions for assurances.
Nadene Hall
