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Are Generators Safe To Use?

Given the increasing frequency of power outages, homeowners and business owners have turned to generators (both permanent standby and portable) to provide power in the event of a grid failure.  Generators are safe if they are correctly installed, used properly and maintained at regular intervals.
When discussing generator safety, remember that are two kinds of generators:  permanent standby and portable.  Permanent standby generators are larger, stationary units that can have the capacity to deliver power to an entire home or business. These generators sit on a concrete or stone base outside of the home or business and are fueled by a natural gas line or by an adjacent diesel fuel tank or liquid propane tank.  These larger generators are typically installed by licensed electricians who can guide you through selection process, permitting and operation.  Portable generators are smaller units designed to deliver power to a limited number of appliances at a home, small business, campground or tailgate.  They can power a refrigerator, a furnace, TV sets, stereos or lights.  These generators can be purchased at dealers or big box home improvement stores and are small enough and light enough to be carried or transported on wheels.  Again, generators can be safe if they are operated and maintained properly.
The safety of owning and using a larger permanent standby generator starts with the selection of a licensed electrician who is experienced with installing and maintaining these kinds of generator systems.  As you select a contractor, make sure that they are not new to standby generator work.  A licensed electrician who is experienced with generator installations will help guide you through the selection process, will know local permitting restrictions and will be able to install your unit properly.  Working with a trusted contractor is also important in that you will likely be working with your contractor under an ongoing testing and maintenance contract.  Remember that a generator that is well-maintained will operate more efficiently and safely!
Because portable generators are purchased, operated and maintained directly by the homeowner (or business owner), the burden of safety falls on the owner of the unit.  Key considerations will be the proper size of your generator, where it operates, safe refueling and proper maintenance.  When selecting your unit, make sure that you buy a big enough unit relative to the appliances served so that it is not overworked, which may lead to overheating.  Before you begin shopping, make a list of the appliances that will be powered by your generator, add up the amps and make sure the size of generator you select produces a comfortable margin of excess amps relative to what is required.  Because portable generators run on gasoline, they must always be used outside so as to eliminate the risk of carbon monoxide (CO) poisoning from exhaust fumes.  Because generators produce electricity, electrocution is always a risk so make sure that you keep your generator dry.  If you anticipate using your generator during periods of rain, you should purchase an open tent or canopy system that will protect your generator from rain and still allow for the free movement of air and engine exhaust.  With regard to refueling, it is important that you never refuel your generator when it is hot.  Always let it cool down before refueling so as to eliminate the risk of a fire.  And never top off your gas tank as gas can expand, creating an overflow situation and potential fire hazard. Lastly, maintain your generator properly.  Proper maintenance will be covered in your owner’s manual and will include recommendations such as:  “exercising” your generator by testing monthly, regular oil changes, check oil, fuel and air filters regularly, use “fresh” fuel and fuel stabilizers, periodic replacement of spark plugs and storing your unit in a clean, dry, area.
Can Generators Overheat?
Like any other piece of motorized equipment, generators have the potential of overheating if not properly located, operated or maintained.
Whether you are using a permanent standby generator or a smaller portable generator, it is important that it is located in an area with open air flow–this is important not only for providing proper air intake to the engine but also for safe distribution of exhaust fumes.  Permanent standby generators and portable generators are both designed to operate outside of buildings, primarily because of the risk of carbon monoxide (CO) poisoning from exhaust.  But they also operate outside to provide a source of fresh air to the engine, which helps prevent overheating.
The risk of overheating can be minimized by operating the generator properly.  Each generator is rated for a certain capacity and if too much load is placed on the generator, it can overheat.  For this reason, it is always a good idea to purchase a generator with a comfortable margin of excess capacity so that it is not overburdened.  Whether you purchase a permanent standby generator system from an electrician or a smaller portable unit from your local big box retailer, make a list of what appliances your generator will deliver power to and add up the watts required.  This way, you can pick the generator that will have some “extra capacity” which will reduce the risk of your generator overheating.  It will also ensure that what you want to operate in a power outage will get the voltage it needs.
Proper maintenance of generators will also help prevent overheating.  All generators, whether permanent standby or portable, have engines that run on a source of fuel such as natural gas, diesel fuel, liquid propane or regular unleaded gas.  Regardless of the fuel source, all generator engines need to be properly maintained in order to avoid overheating (and to ensure proper running in general).  As always, consult your owner’s manual but proper maintenance of generator engines will include:  (1) using the correct type of oil, maintaining correct oil levels and regular oil and oil filter changes,  (2) regular air filter changes, (3) maintaining clean gas filters and replacing them periodically, (4) maintaining a clean muffler and exhaust system.
Can Generators Catch Fire?
A generator can catch fire if it is burdened by too much demand.  All generators, both permanent standby and portable, have power ratings that tell you how much electricity they can deliver to your home or business.   As is the case with minimizing overheating risk, you can minimize the risk of fire by buying a generator whose capacity comfortably exceeds the power demand placed on it.  This can be addressed at the time you purchase your generator from a licensed electrician (in the case of a permanent standby unit) or from your big box home improvement store (in the case of a portable unit).  All you have to do is take an inventory of the appliances you want powered by your generator, add up the wattage needed and then buy a unit with some excess capacity relative to your estimated total wattage needed.
In addition, you run the risk of a fire with a portable generator if you try to refuel it with gasoline while it is still running or if it is hot from running.  Always refuel a portable generator only if it is not running and only when it is cool.  And because gasoline can expand, never top off the gas tank on your portable generator.
Can Generators Be Used Indoors?
Portable generators should never be used inside your home, your garage or in any enclosed space.  Because generators operate with gas-fueled engines, they produce exhaust with lethal carbon monoxide (CO) fumes, which can kill you in a matter of minutes.  When you breathe in CO, it replaces oxygen in your blood and without oxygen, you cannot live.  Another dangerous aspect of carbon monoxide is that you can’t see it, smell it or taste it.  As an extra precaution, as you place your portable generator outdoors before use, make sure that it is placed far away from windows, doors and vents where there could be a risk of carbon monoxide entering your home or business.
By definition, permanent standby generators are always located outside of your home or business as they are large, fixed-place units placed on a concrete pad or pea gravel bed.  Your electrical contractor will know to locate your permanent standby generator away from windows, doors and vents to eliminate any risk of carbon monoxide poisoning.
Lastly, it is always a good idea to install carbon monoxide detectors throughout your home or business.
Can Generators Explode or Blow Up?
Because portable generators run on gasoline, there is always a risk that they can explode or blow up. Never refill the gas tank on a generator that is running or a generator that had been running, is turned off but still hot.  Pouring gas on or near a hot generator presents a risk of the gas igniting, creating a fire and a possible explosion.  In addition, when refilling your generator’s gas tank, do not “over fill” the tank, as gasoline expands and can create an overflow situation, which carries the risk of a fire or an explosion.  And regardless of where you use your portable generator, do not smoke near your unit as you could ignite the gasoline.
As previously mentioned, it is very important not to overload your generator with too many appliances.  If you overload your generator, it could overheat and create a fire hazard which in turn could lead to an explosion. It is advisable to buy a unit whose capacity comfortably exceeds the demand that will be placed on it.  Once again, before you start shopping for your generator, take an inventory of appliances that will be connected to your generator and buy a unit that whose capacity exceeds what you actually need.
Can Generators Kill You?
While both permanent standby and portable generators are designed to be very safe, there is always the risk they can kill you as they run on combustible fuel and produce electricity.  Each can be dangerous.
The principal risk of death from a generator is from carbon monoxide (CO) poisoning that results from operating a portable generator indoors.  The exhaust fumes contain CO, which can quickly kill you if they are inhaled.  For this reason, portable generators should always be operated outdoors and away from windows, doors and vents.  The risk of carbon monoxide death does not really exist with permanent standby generators as they are larger units placed outside of a home or business.  As is the case with portable generators, permanent generators are always located (and operated) away from windows, doors and vents.
Another risk of generator-related death is remote and involves a fire or explosion resulting from improper use of gasoline with a portable generator.  Care should be taken when re-filling the gas tank of a portable generator.  Never refill a tank of a unit that is hot from use as a spillage of gas could result in a fire.  In addition, care should be taken to not overfill a gas tank as gas can expand and create overflow, which in turn could lead to a fire.
Another potential risk of generators is electrocution.  Great caution should be exercised when using a portable generator in rainy weather as handling electrical cords or touching the generator itself when wet could produce electrical shock.  Because we cannot control the weather, it is a good idea to purchase a protective canopy or tent to place above your generator in the event of rain. Make sure that whatever you buy allows for proper ventilation.  Apart from the risks from rainy weather, caution should be taken in handling electrical cords that connect your generator to appliances they are powering.  Be sure to use heavy duty, outdoor-rated extension cords that can carry the load of the appliances served by your generator.
Why Do Generators Explode?

The risk of explosion with portable generators is low but does exist.  Portable generators run on gasoline and there is always a risk of fire and explosion in the refueling process.  You should never refuel a unit that has been running and is still hot, as any gas spillage on a hot surface could lead to fire and possibly an explosion.  In addition, when filling up the gas tank of a portable generator, never top off the tank as fuel expands and can create an overflow situation, which potentially could lead to a fire or an explosion. Lastly, just as you would not smoke at a gas station, never smoke near a portable generator, which creates a potential fire and explosion hazard.
The risk of explosion with permanent standby generators is very remote for two primary reasons.  First, these larger fixed-location generators are professionally installed by licensed electricians, not inexperienced homeowners or business owners.  Second, they require no human intervention (i.e. gas refueling) as they run on permanent energy sources such as natural gas lines, liquid propane tanks or diesel fuel tanks.  And they are self-operating, turning themselves on and off and doing self tests automatically.  So, if your electrician has properly installed your unit and maintains it regularly under a service contract, it should operate safely.
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