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Power Outages, Safety & Emergencies — Back-up Generators

Choose the right back-up generator
Generators are available in a variety of sizes with various features and options. Take the time to look at your particular application to find the model that is best for you. Contact your local generator dealer for information on size, cost and installation.

• Portable vs. standby generators
  
• Power ratings and special features
  
• Typical appliance power consumption ratings
  
• 240V AC and 120V AC
  
• Manual or electric start?
  
• Choose the right size
  
• Fuel types for generators
  
• Cost of generators
  
• Selecting a site for installing your generator
  
• You may need an electrical inspection

Portable vs. standby generators
You will have to decide whether you want a portable or standby generator.

A portable unit gives you the flexibility to move it to other locations as required. They are usually located outdoors or in a well-ventilated space because of exhaust fumes, noise and other considerations. A portable generator cannot be used to power permanently wired equipment such as a furnace fan, sump pump, water pump or hot water tank unless a special interface is installed in the house wiring.

Standby generators offer the convenience of being ready when needed without having to run extension cords, etc.

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Power ratings and special features
The next step is to decide what you consider "critical loads", i.e., the appliances or equipment you need to keep running during a power outage.

Add up the wattage requirements of these appliances and equipment. The table below provides a guideline for typical power ratings, but it is preferable to use the actual ratings listed on the appliances.

In most cases you will want to include the furnace, refrigerator (and freezer if you have one), one or two lights on each floor, and all sump pumps or water pumps (if applicable), and any farm equipment needed to maintain your farming operation.

Additional loads might include an outlet in the kitchen, outlets for your television, AC powered smoke alarms and carbon monoxide detectors, your electric hot water tank, and clothes washer. You can probably survive quite comfortably without a stove, clothes dryer, air conditioning and additional lights and outlets.

Add up the ratings for everything you need to have operating at the same time, then add about 25%. This should provide a good estimate of the size of generator you need. For a house where you want to power the furnace fan, a refrigerator and a few lights, you need a 1.5 kW to 3 kW generator. Remember that larger generators cost more and you also have to consider fuel availability and storage.

For motor loads such as air conditioners, fridges and freezers, you may have to double or even triple the power rating to allow for start-up currents. Most generators can withstand being overloaded by 10% to 20% for a short time, but small generators may not have adequate reserve power to allow motors to get up to speed.

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Typical appliance power consumption ratings

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240 Volt AC and 120 Volt AC
If any of the critical loads are 240 Volt AC appliances, the generator you choose will obviously need to have both 240 Volt AC and 120 Volt AC outputs. Many of the smaller generators (under 3 kW) only provide 120 Volt power.

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Manual or electric start?
You will also have to decide whether your generator should have manual or electric (i.e., battery) start. Electric start is convenient, but means you have to maintain a fully charged battery. Higher power units may require electric start if they are too difficult to start manually.

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Choose the right size
It is not advisable to choose a generator that is significantly larger than you need unless you anticipate that your power requirements will increase within a few years. The larger generator will likely operate less efficiently at low loads than a properly matched generator will when operated near its rating. In addition, fuel availability and storage must be considered when making this decision.

If you anticipate that you may have regular outages or outages that last for several days or weeks, you may want to select a high quality industrial generator to be assured of reliable operation. This would apply to homes, farms or businesses located in remote areas where the restoration of your power could take a long time, or in locations where the restoration may require special supplies and equipment (e.g. on an island served by an underwater cable that fails).

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Fuel types for generators
Generators commonly run on one of four fuels: gasoline, diesel, propane and natural gas. You can choose which one you prefer to use. The lower power and portable units tend to favor gasoline, whereas the larger units, especially permanent installations, may favor diesel, propane or natural gas. The tradeoffs in fuel costs may be insignificant compared to the convenience factor of having the fuel readily available.

In the colder climates, some generators, especially diesel units, may need to have a block heater. This could be powered off your regular AC line since the block will not cool significantly between the time the power goes off and the time you start the engine.

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Cost of generators
Prices for generators vary widely but there are a few general trends that you may want to consider:

• Gasoline, diesel, propane and natural gas units are not drastically different in price.
  
• Compare continuous power ratings, not maximum power ratings.
  
• Electric start adds about 10% to the cost & may not include battery & charger.
  
• Above 5 kW, most generators are designed for permanent installation.
  
• Manufacturer fuel consumption ratings are usually based on 50% of rated load.
  
• Special housings that reduce noise can add about 20% to the cost.
  
• Large units often include transfer switches and other hardware in their price.
  
• Large units may require a battery and battery charger for their control system.
  

It is generally worthwhile shopping around and talking to various distributors about the products they sell.

To determine the costs for installing the wiring, you will likely have to talk to a qualified electrician or contractor who is familiar with the electrical code requirements for these types of systems.

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Selecting a site for installing your generator

Standby generator installations
Standby generators should be located where there is easy access for fueling and maintenance, as well as adequate protection from snow, high winds or other environmental factors. Security from vandalism or theft may also be a concern. Local fire, electrical and building code regulations must be followed.

It is possible to have permanent installations located indoors provided the generator has adequate cooling, a good supply of combustion air, and the exhaust is ducted safely outside. There are special fire regulations and building code requirements that apply to this type of installation. Check with your local authorities to find out what the rules are for your community.

Portable generator installations
Choosing a location for portable units is not usually a problem. Because their exhaust is poisonous, they cannot be operated indoors or in any enclosed space unless you can guarantee there is adequate ventilation. Make sure the exhaust from the generator does not leak into the house. If the generator has exposed moving parts or hot surfaces, make sure small children can't get near it. The easiest mode of operation is to run a proper rated extension cord from the generator to the appliance(s) that you want to operate.

The noise factor may also be a concern in choosing the location. You won't want the noise from the generator preventing you from hearing your radio or television.

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You may need an electrical inspection
Safety should be your first concern. Before starting any wiring installations, you will need an "application for inspection." The completed installation will have to be approved by an Inspector from the Electrical Safety Authority, who will check that you have met all the regulations defined in the Ontario Electrical Safety Code. It is strongly recommended that you consult with and hire a qualified electrician to assist and advise you.