How to safely use a portable generator
Portable power generators are a convenient source of electricity when there is no grid power such as camping, working in bush, living off grid, after a storm or cyclone. But if not handled safely they can be deadly. The two biggest killers when using a portable generator are –
Electricity – misuse of the generator, over loading it, having power cords in water or exposing electrical appliances to water are all deadly.
Carbon monoxide (CO). An odourless, tasteless, invisible toxic gas that will kill you in a matter of minutes. Don’t run a generator indoors (cabin, tent, house, shed). Make sure to position it well away from windows and doors to prevent fumes entering the building.
DISCLAIMER: When you go to buy a generator discuss your needs and usage with the retailer to ensure you get the right type and size of generator for your needs. Ensure you read the generator operating manual to fully understand the generators features, safety guidelines and maintenance requirements. Follow all safety guidelines in the manual and have the generator repaired and maintained by trainer professional. Do not carry out any electrical repairs or modifications yourself as it can be fatal to yourself or those around you. And it is illegal to do electrical work yourself if you are not a licenced electrician. NEVER plug a generator into your house power circuit as it is extremely dangerous. Electricians can install a system into your power box for attaching a generator to your house safely.
Generators come in a range of sizes 1kw, 2.5kw, 8.5kw 10kw and so on. They also come in 10amp and 15amp for domestic use and can be petrol or diesel. Smaller generators are light enough to carry and the bigger heavier versions usually have wheels and handles.
Carbon monoxide is an odourless, colourless, deadly gas created by combustion. Not to be confused with Carbon dioxide which makes up 0.04% of our atmosphere and is needed for life on this planet. Carbon monoxide can come from many sources such as petrol or diesel engines (like generators or cars), your internal fire place not venting to outside properly, and other combustion sources.
Symptoms of Carbon Monoxide poisoning include-
- Chest pain
- Leading to unconscious and death
If you come across someone unconscious and suspect Carbon monoxide poisoning don’t rush into the same environment as you could become another casualty, call for the emergency services. There are news stories every year where someone was in a tank, basement and goes unconscious so others rush in and they fall over too.
The generator output usually is 10amp or 15amp for smaller domestic generators. You only need 0.1amps to be fatal, at this strength you get a very painful shock, you stop breathing and muscles contract which keeps you griping the power cord/appliance continuing the electric shock.
Faulty or damaged generators can be still working and you don’t know it until you go to use something or touch something. Having a properly maintained generator with the added safety features could save your life.
What is the purpose of ELCB’s, RCD’s, Earth stakes and circuit breakers?
ELCB, Earth Leakage Circuit Breaker, is an older version of an RCD or RCCD (Residual Current Circuit Breaker).
RCD, Residual Current Device disconnects the power flow if it detects any current leakage through either the earth stake or through earthing from power socket such as yourself or faulty equipment. One article I read said ‘RCD’s save people, Circuit breakers save equipment’. Circuit breakers cut out when they detect a large draw in power which can be in fatal amounts, so don’t rely on it to save you as you could have received a fatal dose before the breaker kicks in.
Some generators have RCD’s and some don’t. Generators with RCD’s should have a bolt to connect an Earth wire to an Earth stake. For RCD’s to work they must be connected to an approved earthing system. A lot of people use generators with RCD’s and could not be bothered setting up an approved earthing system, this will not save them if a fault was to occur.
Generators without RCD’s are used more as portable generators for use with double insulated power tools. With this system if there is a fault or damage to the power tool leads you become the Earth stake resulting in serious injure or death. If using this type of generator best to use a safety power board with RCD switches installed.
Check the capacity of the safety power board before buying it as there may be 4 outlets but it is only rated to 2400w so you can’t attach 4 x 1000w appliances to it such as 4 lighting towers. For more information on working capacity see below.
NOTE: generators without RCD’s or don’t have Earth stake installed can have electrical faults and you may not know until something goes wrong and you are electrocuted (dead).
Earth stakes are used to direct current to the ground if a fault was to occur, without a stake you could become the Earth stake. Not all generators need earth stakes. Discuss requirements with your retailer when you buy a generator. You may have to buy the Earth stake and accessories from your local electrician and discuss installation requirements with them. The efficiency of an Earth stake will be determined by how it is installed and the moisture level in the soil.
Weather, keep the generator out of the weather. This can be rain or flooding situations but also leaving it unprotected outdoors can cause UV damaged to the plastics, wires, pull rope and more.
Fire, for fire to occur you need 3 things; fuel, oxygen and heat/spark. Oxygen is all around us and is needed to run the combustion appliance. Fuel can be either the petrol or diesel in the generator or fuel loads (dry grass, cardboard etc) you have close to the generator. For example, placing a generator in long dry grass is a fire risk.
Another big fire risk is refuelling a generator when it is hot. The motor and exhaust are hot as you have just turned off the generator and couldn’t be bothered waiting for it to cool down so you fill it up with petrol. The fumes are flammable (especially if you are smoking while doing it) and if any fuel is splashed onto the hot surface there is a fire risk.
Fuel, as I have said above, refuel when the generator has cooled down. Also store the fuel away from the generator in a shady area. According to the BP fuel storage fact sheet the shelf life of fuel in an Australian Standards approved sealed container is rated to one year. But once the container is open it has a shelf life of 6 months at 20 degrees and 3 months at 30 degrees.
Fuel left in equipment has a shelf life of one month (see the BP fact sheet for more information). This is because fuel is made up of different chemicals and the more volatile chemicals evaporate first making the fuel less effective.
What size generator do I need?
To work out what size generator you’ll need to grab a calculator and do some maths. But first some definitions.
Watt (w) is a unit of power.
Kilowatt (kw) is 1000 watts.
Amps, most domestic appliances in Australia work around 10amp and 240v power system. Appliances the have different requirements have a transformer built into the power cord such as laptop or mobile phone. Domestic generators are rated to either 10amp or 15amp output.
15amp generators have a slightly different power outlet socket with a longer earth slot. You can fit a 10amp power lead into 15amp power socket BUT you can’t fit a 15amp power lead into a 10amp generator power outlet. And DON’T file down the earth pin as drawing 15amps will overload the 10amp outlet making the circuit breaker to drop out or damage the generator.
NOTE: if you are camping or holidaying in a caravan using 12v appliances designed for car cigarette lighter sockets you will need an adaptor to plug it into a 240v generator or you can just use a battery system charged by either solar panels or a generator.
To calculate watts
Volts x amps =watts 240v x 1.8amps = 432w (watts)
1000 watts equals 1 kilowatt
To calculate kilowatts
Watts / 1000 = kilowatts or
Volts x amps /1000 = kilowatts
432w / 1000 = 0.432kw
2350w / 1000 = 2.350kw
So, to find out what is the power requirement of an appliance look for the information plate or area. The information can be written as either watts or volts. In Australia all domestic power appliances say 220-240v and 50-60Hz as that is what the parameters of the power grid. If your appliances say something different, they may be from overseas and need an adaptor.
This iron data panel says 2000 -2400w. A lot of appliances draw more power on start up and then level back. So, with this information you would need more than a 2.4kw generator to run the iron. I run my iron on a 6.8kw generator and you can hear when the iron kicks in with the tone of the motor.
A pedestal fan is rated to 50w. On a 1kw generator you can run up to 20 fans theoretically. I say theoretically as it is not good to load a generator to 100% as the power rating is more of an average and if the generator is old parts may be wearing out and not working at 100%. Drawing too much current will cause the Circuit breaker to drop out. And the more power you draw the faster the generator will run out of fuel.
You need to consider the capacity of all electrical equipment (extension leads, power boxes) used with the generator. The generator will have 2 power outlets so there is a temptation to plug a multi outlet power board into each socket. The power socket is rated to 10amps, extension leads are to be rated to 10amps, power boards are to be rated to 10amps. The maximum power you can put on this power socket is 2400w without tripping the circuit breaker (assuming the generator is rated 2.4kW or higher.)
I was in a team in the field and they were setting up 4 lighting towers. Each lighting tower had 2x500w (1000w total) lights on it. They ran the leads from the tower back to a safety power board with an RCD which was connected back to the 6kw generator by an extension lead. As they started to turn on the lights the system tripped out. As they started problem solving, they realised the draw on the socket and power board was 4000w on a system designed for 2400w. So, they had to run 2 separate systems to run the 4 light towers.
If you have a power tool or appliance with the power rating in ‘horsepower (hp)’. One horsepower equals 746 watts or 0.746 kilowatts.
How to safely use a generator?
1. Determine what size generator and accessories you need for the job.
2. Set up the generator in flat ground away from building openings. Flat ground ensures oil and fuel is accessible by all generator components.
3. Ensure the generator has protection from the weather but don’t have the cover touching to the generator during operation. For example, covering the generator with a tarpaulin while running will melt the tarp, overheat the generator (air cooled motor, no radiator) and limits air needed to run effectively.
4. Check the oil level is between Hi and Lo levels
5. Fill up fuel, wiping up any spills on the generator.
6. Ensure there are no power leads plugged into the generator before starting.
Most small engines (generators, mowers, pumps) have similar starting procedure (check your manual).
Some generators have both rope start and push button start which is easier than pulling a rope. It can be as simply as pushing a button to start it after you check the fuel is turned on. Once running plug in power lead or appliance.
Pull rope starting
1. Check the fuel tap is turned on.
2. Switch power on/off button on.
3. Turn on choke (if there has been a break in using it for a while. If you just turned it off it may not need choke to be turned on as the engine is still hot.)
4. Pull on the starter cord till you feel some resistance. Let the rope wind back in and then give it a hard pull. Taking it to the point of resistance puts the cylinders inside the motor into compression making it easier to start.
5. When it starts put the choke into the run position.
If you have problem starting the generator, stop and re assess the potential problem (fuel tap not on, no fuel in tank, on switch not on, dirty old fuel, faulty spark plug, neglected maintenance or you need someone else to pull the rope as you are not strong enough).
Then plug in power lead or appliance into the socket.
To turn the generator off
1. Unplug the appliances
2. Push the power off switch.
3. Turn fuel tap off
4. Allow to cool down before handling or putting into storage.
Basic generator maintenance
1. Check oil levels, top up if required.
2. Clean air filter.
3. Check all nuts, bolts, are tight.
4. Check for any oil or fuel leaks (tank and fuel lines).
5. Test RCD breaker regularly throughout the year.
6. Carry out any other maintenance requirements set out in your operator’s manual.
7. Start and run about every 4-6 weeks to keep everything working.
Any damage or faults must be fixed by qualified professionals.
Generators and the environment around running generators can be dangerous. Following safety guidelines and your operator’s manual will ensure your safety and the safety of those around you. Ensure you discuss your requirements and how you will be using your generator with your generator retailer to make sure you get the right one.
If you are buying a second-hand generator, have it checked by a professional to check for any electrical faults and mechanical issues. Really old generators may have no or worn-out safety features making them dangerous.