Home generators 101

Home generators can give you peace of mind by keeping your power running through a blackout. A fully automatic generator senses an outage and begins producing power immediately. When power returns, the generator shuts itself off automatically and returns to standby mode. Because the generator is hard-wired into the electrical system of your home, your furnace, well pumps and lights will continue to operate during a power outage, even when you’re away. They also produce consistent and stable power that computers and other sensitive electronic equipment can use safely.

How much power coverage is right for you?

If you’re thinking about purchasing a home generator, you’ll first need to decide how much protection you need and want. Here are a few types of coverage to consider:

• Essential Circuit Coverage: Many homeowners choose to cover only certain electrical circuits such as those for heating and cooling systems, refrigeration and lights. This option is the most cost-effective.
• Managed Whole-House Coverage: For light and medium appliance usage, a smaller generator provides coverage by managing how much power appliances can use.
• Complete Whole-House Coverage: When the power goes out, everything comes on and stays on, no matter how many circuits there are.

Measure your circuits before you buy

We highly recommend having a generator installation specialist measure the load of the circuits and appliances you intend to back up with your generator. The specialist will use an amp meter to measure the amount of power required to start each appliance. This load measurement gives you the total power requirement for the backup power you need.

Natural gas vs. propane

If you don’t have natural gas at your house, you’ll need to fuel your generator with a propane tank. Your generator’s runtime will vary depending on the size of the generator and the appliance load being placed on it. Here are the hours of operation for a typical 16-kilowatt generator running at half load:

• 100-gallon LP tank: 50 hours
• 250-gallon LP tank: 125 hours
• 500-gallon LP tank: 251 hours
• 1,000-gallon LP tank: 503 hours¹

What about the noise?

One frequent concern homeowners have is that their backup generator will be too loud for their neighborhood. Generators are known for being quite noisy, but the truth is, backup generators designed for residential use aren’t that much louder than a typical air conditioner or leaf blower. The main difference, though, is that a home generator is often operated for the entire duration of a power outage. This could be a few hours or even days, so it’s feasible that the constant hum of your generator may start to annoy you and/or the neighbors after a period of time.

Your first option may be, of course, to purchase the quietest generator possible, but if pure power is your priority or you already own a noisy generator, it’s possible to reduce generator noise by trying any or all of the following:

• Reduce vibration. Much of the noise produced by the generator is from vibration. You can use vibration dampening material to reduce this noise. One way to do this is to add a rubber washer to the screws that secure the engine to the frame. This can help absorb some of the vibration and, hence, the noise. Be sure to consult your owner’s manual first and follow all safety procedures.
• Use an isolation mount. Place the generator on an isolation mount made of rubber-type padding. This helps reduce noise by keeping vibrations from the generator from reaching other structural components.
• Add an acoustic barrier. Some models of generators come with an enclosure that absorbs sound or have an enclosure specific to that model that can be purchased separately. If an acoustic barrier isn’t available for your generator model, you can purchase a sound-dampening barrier fence to help keep decibel levels to a minimum.
• Use free-standing acoustic panels. Free-standing, self-supporting, all-weather acoustic panels can be placed around the generator to help muffle the sound. They’re easy to move and provide a temporary solution to noise reduction. The panels are typically used in manufacturing environments to temporarily enclose a source of noise, such as loud machinery.²

Routine maintenance is important

All home generators need periodic oil and filter changes to ensure maximum performance for years of reliable service. You can refer to the owner’s manual for routine maintenance procedures and schedules. Better yet, ask your installer if they offer service/maintenance contracts.

Routine system checks are important, too

Because home generators typically aren’t used regularly, it’s easy to forget about them. For many, after the installation and initial tests, the generator just sits there waiting for the next hurricane or major storm to knock out power. The good news is that many modern home generators come with automatic testing features. You may see a green light or icon on a control panel that indicates the generator has completed a diagnostic cycle.

Nothing, however, can replace a manual test where you actually turn off utility power and test the generator under emergency outage conditions. This kind of testing gives you assurance that the generator works. It can alert you to needed repairs or maintenance issues before an emergency arises. Just like an undriven car needs periodic starting to stay in top shape, so too does your home generator.

How to test your home generator

First, don’t be intimidated by your home generator, because periodic testing is as simple as following these steps:

1. Flip the main breaker to “OFF.” Flipping the main utility disconnect switch will cut power from the incoming utility line and force the standby generator to turn on. (The main utility line coming into your home may be in a box outside of your home or in your garage or basement.)
2. Listen for the generator to turn on and the transfer switch to click. The generator may run for a few seconds to a minute before the transfer switch clicks and power is distributed.
3. Let your generator run for about 10 minutes. Give your generator time to warm up and “exercise.” This is a good time to walk through your home and check to see that power is being fully restored.
4. After running a test, be sure to turn the main breaker to “ON.” Wait again for the transfer switch to click and the generator to return to standby.

Record the test and follow up if needed

Make a note of the date you tested your generator, so you’ll know when it’s time for another test. If you experienced any problems during your test, contact a residential generator specialist for a more thorough test and inspection.

Test your generator at least a couple of times a year — or more often if you think it’s needed. You may also want to run a test in advance of hurricane season or if there’s a major storm headed your way.³