Using a Generator When the Power Goes Out
By Laura Foster
(David King of McNamee Road provided the impetus for this article in January 2009 when local roads had 3 foot drifts of snow. PGE’s website is the source of the material used below.)
Grabbing a generator at Home Depot is not the same as getting some extra D cells for the flashlight and radio. With knowledge and an investment, our rural properties can be electrified instantly when there’s an outage, but amateur efforts can be outright dangerous. Anyone who does not understand the phrase, “110 v circuits that are 180 degrees out of phase” should not use a generator without some guidance and education.
There are two types of generators: portable and stationary. A portable generator is the most common choice for home use. Most portable generators are “plug and play.” 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 best for people who need to keep life-support equipment powered at all times. Permanently installed auxiliary generators must meet electric codes and have a transfer switch to prevent dangerous back-feed of electricity into power lines. PGE requests that you notify it if you have a permanent generator.
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.
Selecting the right generator
The purchasing considerations for portable generators are:
• 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
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 PGE’s Power Quality Hotline at 503-736- 5750 or 800-270-7016.
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 back feed into PGE’s utility lines, putting our repair personnel at risk of injury.
• Always operate a portable generator outside. Since it is gas powered, place it in a well-ventilated area away from doors, windows and garage. Otherwise, deadly, odorless carbon monoxide can be drawn into the house.
• Don’t get shocked! Use only an outdoor-rated, grounded extension cord. One with a GFCI (ground-fault circuit interrupter) is best. Follow the 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, thinking 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.
• Gas-powered generators. This type of generator avoid burns. Also, let the engine cool before you refuel.
• 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.
For more information, visit www.portlandgeneral.com and search for “generators” or call PGE at 503.228.6322, 7 a.m. to 7 p.m. Monday through Friday. If you’d like one of PGE’s pamphlets, “Medical Outage Checklist,” “Home Generator Safety” or “Outages and Safety,” contact the Ridge Runner at 503.621.3450 and we’ll get them to you.