Learn about different types of generators, how to choose the right one for your needs and operate it safely.
What is a generator
An electric generator helps supply power if utility power is lost for an extended period of time. While a portable generator is rugged and dependable, its power can be significantly lower in voltage and frequency regulation than utility power.
There are two types of generators:
- A portable generator is the most common choice for home use. Most portable generators are “plug and play.” That is, you can install the equipment yourself.
- A stationary generator is connected to your home wiring and requires the services of an electrical contractor for installation. This option is the best choice for people who need to keep life-safety equipment powered at all times. For specifics, contact the PGE Power Quality Hotline 503-612-5750 or 800-270-7016, or email us.
If you will use your generator to operate an appliance with a large motor, you may need to install a power conditioning device such as an uninterruptible power supply at sensitive appliances. Check the manufacturer’s specifications for details.
It is also important to know that the National Electric Code requires a transfer switch be installed if you use a generator to power some loads in your home.
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Selecting the right generator
Key purchasing considerations for portable generators:
To make sure you get the right generator for your needs, look for products that meet these specifications.
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- Valve location
Overhead valves enable engines to last longer than engines with side-mounted valves.
- Run time
Run time is usually specified at one-half load. More loading means less run time.
- Starting method
Compression release on pull-start models makes starting easier.
- Low-oil warning
Auto shutdown feature prevents damage to engine when the oil is low.
- Spark arrester
A spark arrester should be used when the generator is located near combustibles.
- AC voltage
120/240-volt generators can power 240-volt appliances such as AC units and clothes dryers.
- AC outlets
Twist-lock outlets provide a more reliable connection to the generator.
Common questions about generators
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Q. How large a generator should I invest in?
That depends on how much equipment you need to operate during a power outage. For assistance in sizing a generator, call the Power Quality Hotline at 503-612-5750 or 800-270-7016.
Q. What should I do about my life-safety equipment that needs constant power?
A stationary, or permanently installed generator, is your best choice. After an outage, it can restore power in seconds and support all loads as long as needed.
Q. Will all of my equipment run properly when powered from a generator?
Newer generators feature electronic governors, which can regulate voltage to plus or minus 6 percent of nominal or better. Most equipment should work with this type of voltage regulation.
Q. How can I use my home generator to power lights in my home or my electric water heater?
To power circuits in your home safely, you need the right switch. You can choose an electrician-installed transfer switch, which will cost $500 to $800. Never plug your generator directly into an outlet in your home. You can overload your electrical circuits and cause a fire or some of the power you generate can backfeed into PGE’s utility lines, putting our repair personnel at risk of injury.
For more information, contact an electrical contractor, PGE’s Power Quality Hotline at 503-612-4615 or 800-270-7016, or email us.
A home generator can be a convenient back-up solution during a power outage, if you use it safely. Before turning on a generator, always read and follow the manufacturer’s instructions!
Avoid deadly mistakes with portable generators
Always operate your portable generator outside.
Since it is gas powered, place it in a well-ventilated area way from doors, windows and your garage. Otherwise, deadly, odorless carbon monoxide can be drawn into your house and poison your family.
Don’t get shocked!
Use only an outdoor-rated, grounded extension cord — one with a GFCI (ground-fault circuit interrupter) is best. Always follow manufacturer’s instructions for grounding the generator, too.
Never “back feed”
Sometimes, a person might try to “doctor” an extension cord to plug a generator into a regular household outlet, imagining this will power the whole house. This is extremely dangerous! Connecting a generator with a regular outlet can not only ruin your home’s wiring and start a fire, it can also back feed electricity into the utility system and energize a line thought to be without power. An unsuspecting PGE lineman could be seriously injured or killed, not knowing the line is live. Only connect individual appliances to the receptacle outlet of the generator, following the instructions in your owner’s manual.
Install a transfer switch
The safest and best way to prevent portable generator back-feed problems is to install a transfer switch. A transfer switch permits the home’s wiring system to be easily and cleanly disconnected from PGE’s system and allows you to control the flow of electricity to those circuits you need most (like the furnace fan or refrigerator). Transfer switches are not inexpensive and require installation by a licensed electrician.
This type of generator can get very hot during operation. Use extreme caution to avoid burns. Also, let the engine cool before you refuel.
Children and Pets
Keep children and pets away from portable generators at all times.
Turning it off
Turn off all equipment powered by the generator before shutting down the generator.
Don’t overload your generator. Read and follow wattage guidelines in your owner’s manual.
Special considerations for permanent auxiliary generators
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Permanently installed auxiliary generators must meet electric codes and have a transfer switch to prevent dangerous back-feed of electricity into power lines. Contact a licensed electrician. Also, please notify PGE if you have a permanent generator.
If a family member depends on medical life-support equipment, a back-up generator is important to consider in case of an extended power outage.
Emergency fuel supply
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Be well prepared by having enough generator fuel on hand to last through an extended outage or natural disaster. Emergency preparedness experts advise stocking up with supplies to last at least 3 to 10 days.