If your generator does not start, double-check that the fuel line is open. A recoil cord is a cord with a T-shaped plastic handle, like the cord you start a gas-powered lawn mower with. Many small portable generators have these.
If you aren’t sure which position is the AC voltage testing position, consult the manufacturer’s instructions for your voltmeter.
If the voltmeter cable doesn’t have a built-in alligator clip, you will need to get an alligator clip to use to clip the metal tip of the cable to the frame.
The generator might have different output plug outlets for different voltages. For example, it might have a 120-volt output outlet and a 220-volt outlet. The outlets will be labeled and may look different. You can test both of them in the same way. Outlets with a 120-volt output are most commonly used for plugging in standard electrical devices, while 220-volt outlets are typically used for things that require more power, such as clothes dryers and welders.
For example, if your generator has a 120-volt output, the display should show 120 volts or very close to that number, unless there is a problem with your generator.
If the generator is water-cooled, check the levels in the radiator or coolant tank to verify that it has enough coolant as well. Make sure the reservoir is filled to within about 1 in (2. 5 cm) of the top.
Listen for any strange sounds during this step and stop the generator if anything seems wrong. There shouldn’t be any sputtering or clunking noises; the engine should sound smooth and consistent.
You can buy or rent a load bank if you plan to perform this test yourself. Keep in mind that unless you run a facility with multiple generators or you need to perform frequent load tests of generators, it doesn’t make much sense to purchase and keep a load bank on hand. Companies that perform generator load testing for you will bring a portable load bank to your premises to perform the test.
The circuit breaker switch is located on the generator’s control panel.
For example, if the generator can put out 50 amps of power, you could flip on 1 load switch for a 20 amp load followed by 3 load switches for 10 amp loads. You’ll hear the engine noise of the generator lower as you add loads, this is totally normal. However, continue to listen carefully for any noises that sound like a mechanical problem and shut the generator down if you hear anything suspicious.
For example, heavy-duty portable generators, such as those used by contractors, might be tested for 4-8 hours. Continuous duty generators or industrial generators must be load tested for anywhere from 1 day to 1 week or more. Consult a contractor if you aren’t sure how long to run the test for. Output numbers to monitor include voltage, amperage, kilowatt load, and hertz. If you are running a 50 amp load test on a 220-volt generator, make sure that the readings for amps and volts on the load bank stay at these numbers for the duration of the test.
For example, if the generator has an output of 50 amps, leave it running under a 10 amp load from the load bank.
This is just for the purpose of shutting down the generator after a test. In normal use, try not to run your generator on a light load often because it can lead to wet-stacking, which is when unburned fuel builds up in the exhaust system of the generator.
Do this all within 5-10 minutes of switching off the last load to avoid leaving the generator running under no load for too long.
