Portable Generators

“Never again”

As people shivered in the dark or were forced out of their homes, that was the very common refrain in a large part of Eastern Canada in January 1998. Although the freezing rain only lasted for a few days, it caused so much damage to the power grid that some homes were deprived of electricity for months. Many of the homes that depended upon electricity to fuel or operate their heating systems simply froze and suffered all sorts of damage as a result. If only those homes had been equipped with a generator.
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Before we begin, a word about amps, volts, watts and more
Characteristics
Accessories
Maintenance
Safety

Before we begin, a word about amps, volts, watts and more

You cannot make an informed choice of a generator without some understanding of watts, amps and volts, as these items are measures of generator output and provide the answers to the questions “How much?” and “For what?” So, if you’re not an electrician, and most of us aren’t, think of electricity in terms of water coming out of the end of a pipe. With this image in mind:
  • An amp (Ampere)
    A unit of measurement that indicates the flow rate of electrical current. Using the water flow analogy, amps indicate the volume of water flowing through a pipe.

  • A volt [V]
    A unit of measurement that indicates the amount of electrical pressure. A volt would be a measure of the force of the water flowing out of the end of a pipe.

  • A watt [W]
    A unit of measurement that indicates electrical power performance. Always with water flow in mind, a watt measures how much work is being done i.e., how fast a turbine or waterwheel would be spinning.

  • Alternating current (AC)
    Simply put, AC is the form of current that is generated by the power companies and that supplies all our homes.

So how does this apply to generators? To power four 60-watt light bulbs you would need a generator that supplies at least 240 watts (4 x 60). Actually you need more than 240, as there are always variations in current flow. You may also be tempted by a generator equipped with a 240-volt outlet that, presumably, would power an electric oven and is present on many models. If so, you should be aware that the amperes generated might not be up to the task. The best solution is to first determine your needs and follow up by consulting an expert before making a choice.
Power, power and more power
Generator models range from units so small that they can be carried with one hand and are easily transported to a job site to power an electric drill or saw, to industrial models designed to supply the emergency power needs of an entire hospital. Larger models can supply power to the entire house. For our purposes, we’ll limit our discussion to the domestic-use models designed to be employed as backups in power outage situations or as sources of electrical power in remote areas where there are no AC outlets. In most of these cases, the units are portable.

Power output for portable, domestic-use generators is usually expressed in watts. The smallest models generate 1,000 to 1,500 watts, while a 6,500-watt domestic-use machine is at the high end for most needs. Again, you will determine your choice based on how and when you plan to use your generator. After calculating your needs, it’s a good idea to add a 20% safety margin to prevent generator overload.

It’s fairly rare to find in a home a domestic-use generator so large that it entirely replaces the normal electric current. Instead, most orient their purchases towards assuring basic systems such as water delivery (if your water comes from a well), heating and food refrigeration, lighting and cooking. In the case where your home is electrically heated with standard baseboards, remember that one 5-foot baseboard will use 1,500 watts, making generated electric heat for an entire house a difficult goal, particularly in January sub-zero temperatures. Use appliances and light bulbs that draw a limited amount of current. A 40-watt bulb, versus a 100-watt, may be adequate for most of your needs and it will free up power for other applications.
Gasoline powered generators
Due to its availability and portability, gasoline is by far the most common fuel used in domestic generators, but there is also a wide selection of models powered by diesel fuel, propane and natural gas. These tend to be less portable due to their size (diesel) and fuel containers (propane and natural gas), but are good alternatives to gasoline when used in fixed, permanent installations. Smaller gasoline models are mostly air-cooled, while the larger machines are often equipped with radiators and are water-cooled.

2-Stroke/ 4-stroke
Generators are powered with 2-stroke or 4-stroke motors, although 2-stroke motors are gradually being phased out. 2-stroke motors require the user to prepare oil/gasoline mixtures in ratios established by the manufacturer. Never use pure gasoline in a 2-stroke motor, as it will burn out in short order. Like automobiles, 4-stroke motors use pure gasoline, with a separate system for oil lubrication. To prevent 4-stroke motor seize-up, always check the level before starting the machine and top up the oil if necessary.
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