Having a backup generator in your home is a great idea for those times when you need some extra power, such as during a storm or when you’re out of town. But it’s important to know how to hook it up correctly. If you don’t do it right, you could be in for some serious problems.
Isolation switch
Adding an isolation switch to a backup generator hookup is essential for safety. This device is designed to prevent electrical workers from being sucked into the main panel when backfeeding power from the generator. This is a very serious risk for technicians who work on electric lines.
The main electrical panel in a home is equipped with a main switch that reduces power surges. This switch is typically switched off when the power is off. However, if a backup generator is hooked up to the main panel, the generator power may backfeed into the local electrical grid, which is unsafe.
Backfeeding power into the electrical panel is dangerous for electrical workers, who could become exposed to carbon monoxide from exhaust fumes. Installing an isolation switch for a backup generator hookup will also protect technicians from being shocked by the electricity.
Transfer switch
Using a transfer switch for backup generator hookup can be a smart way to keep your house running in the event of a power outage. Transfer switches help you avoid the pitfalls of backfeeding into utility lines and repeating surges. They also allow you to switch between various loads and appliances.
Transfer switches come in two basic varieties – manual and automatic. A manual transfer switch allows the user to manually switch from grid power to generator power. Manual transfers require some knowledge of circuits and circuit breaker circuits. They are less expensive and easier to install than automatic transfers.
Automatic transfers have the advantage of automatically switching power from one source to another. They are ideal for large properties in blackout-prone areas. They also provide temporary electrical power during an outage. They are especially helpful in commercial settings and public spaces.
Fuel supply
Whether you are in the market for a standby generator or have one already, it’s important to understand your fuel options. Propane, natural gas, and diesel are all available and offer varying advantages for different applications.
Diesel is one of the most common fuels. It is easily available and has a reputation for reliability. It is also less volatile than other fuels, making it less likely to go bad.
Natural gas is a popular fuel, but requires a connection to your local utility grid. It is cheaper and less volatile than other fuels. It also burns cleanly.
In most residential applications, natural gas makes sense. It is less expensive and requires less disruption of your property. It is also available at home and business locations that are connected to the local utility grid.
Electrical grounding requirements
Adding back-up power to your home requires a transfer switch and proper electrical grounding requirements. Failure to do so can lead to shocking electric-company employees or back-feeding live power into your local electrical grid. Whether you’re adding a new backup generator or installing a transfer switch for a preexisting generator, it’s important to ensure that all connections are properly installed and tested.
The NEC specifies a minimum size for grounding wires. The requirements vary based on local electrical codes. While the NEC states that the minimum size is for practical safeguards, the actual size should be designed to fit the installation.
The NEC also specifies that a grounded neutral must be grounded only at one location. Typically, this is at the utility service entrance. A wye/delta isolation transformer is also used to separate the generator neutral from the system ground. This allows for paralleling of circuits and a lower potential difference between generators.
Safety precautions
Having a backup generator installed in your home can protect your family from an unexpected power outage. However, backup generators are dangerous equipment. If used improperly, they can cause electrocution, burns and carbon monoxide poisoning.
Backup generators should only be used by a qualified electrician. They must be operated outdoors and in a well-ventilated area. It is also important to keep your generator and extension cords free of cuts.
Make sure that you use proper fuel for your generator. Extra gasoline should be stored in a cool, dry place. Gasoline is very flammable. Never use a portable generator to run flammable liquids such as gasoline or diesel fuel.
Whenever possible, operate your generator under a clear canopy or on a dry surface. Never operate a generator near an open window or door.