An essential accessory for most generators is a transfer switch, although it’s possible to connect a generator without one. The purpose of a transfer switch is to change the power source from the main electrical line to the generator in case of an outage. Today, most people use a transfer switch for safety reasons and because it allows you to power many devices simultaneously.
Using a transfer switch is mandatory for connecting a generator to a house in some regions. However, there are other ways to connect a portable generator, such as with extension cables and GenerLinks.
A transfer switch is one of the leading legal methods of connecting a generator to a house. It’s safe, and it allows you to power appliances that are hard-wired in a house, such as water pumps, dryers, or washing machines.
A transfer switch also allows you to use the full capacity of your generator. It’s similar to a secondary service panel. When there’s a power outage, the energy flows from the generator to the transfer panel, which acts as a distribution point for the energy in your home.
A transfer switch system requires two main parts. The first one is an outdoor connection port. This piece allows you to connect a cable from your generator to the port and through the port to the transfer panel.
The second essential part is the transfer switch panel. This panel is usually placed right by the main service panel. You can think of it as a smaller secondary panel that connects to the generator and starts working in case of an outage. Part of the transfer switch installation process involves deciding which of the circuits powered by your generator you want to have on the transfer panel.
When there’s a power outage, your generator should start providing backup power to your home. An automatic transfer switch notices an outage and automatically changes the source of power from the grid to the generator. The current starts flowing from the generator to the transfer panel and is distributed through the different circuits.
One of the main purposes of a transfer switch is to separate the generator’s current from the main electrical line. The current never comes from the grid and your generator at the same time. Power from the grid travels through the main service panel or comes from the generator and through the transfer switch panel.
This separation is crucial for safety reasons. It prevents energy from your generator from backfeeding through to the main panel and the grid. This would be very dangerous and places the electricians trying to fix the outage at risk. The power from your generator could travel back to the grid and electrocute people working on the grid’s lines.
There are two kinds of transfer switches. Automatic transfer switches instantly connect your generator to the house when there’s a power outage. When the main electricity line comes back, the transfer switch changes the connection back to the main service panel and the grid.
You have to manually flip the switch on the transfer panel with a manual transfer switch when there’s an outage. When the power outage is fixed, you have to flip the switch again to connect back to the grid.
The laws regarding transfer switches vary across states in the U.S. In many areas, the law requires installing a transfer switch for safety reasons. Make sure to check the regulations in your area regarding generators and transfer switches because the type and location to install a transfer switch may vary by state. In most cases, if your generator is 5,000 Watts or more, you’ll need a transfer switch for safe operation.
When learning how to connect a portable generator, a transfer switch is generally the safest and most convenient way to do it. It doesn’t matter if you are using a standby, an inverter, or a portable generator.
However, if you have a generator below 5000 Watts, here’s how to connect a portable generator to a house without a transfer switch:
If you have a portable generator and want to power a limited number of home appliances, you could simply use ordinary extension cords. You plug the extension cords into the generator’s outlets and then run the cables into your home. Then, you can connect the extension cords to the devices you want to power.
This is the process you’d use when operating a portable generator during a camping trip or an off-grid project. You would connect devices directly to the generator. When connecting a generator to a home, the downside of this method is that not all home appliances work with cords. Some are hard-wired into a home’s electrical lines.
Also, this method limits the amount of devices you can power, meaning you fail to use the full capacity of your generator. It’s like pouring a lot of water through a very small funnel. You aren’t using the generator in the most efficient way.
Another option for how to connect a portable generator to a house without a transfer switch is to use a piece of hardware called a GenerLink. Essentially, a GenerLink is a cylinder that fits between your meter and meter base. Although the cost is higher than a transfer switch panel, the installation costs are very low. In the end, the total cost of a GenerLink is similar to that of a transfer switch.
The GenerLink has a port where it connects your generator. Inside the GenerLink, there’s a system that recognizes whether the grid’s power is on or off. When the grid power is on, you are free to connect the generator to the GenerLink. The GenerLink will prevent the current from backfeeding into the grid, and the generator’s current will power your home through the main service panel.
When using a GenerLink, keep in mind that even though portable generators can produce as much as 7,000 Watts, a portable generator might not be able to power your entire house. Therefore, you have to choose the circuits you want to power. In this case, instead of using the transfer panel, you just switch off the circuits you don’t need on the main service panel.
If you regularly experience power outages and want protection from power surges and outages damaging your appliances, an automatic transfer switch is the most convenient option. It works automatically at the beginning and end of a power outage, and you don’t have to do anything. In lieu of an automatic transfer switch, a manual transfer switch is the next best option.
While a GenerLink may seem convenient, you have to turn off some circuits on the main service panel before and after an outage. Refer to the National Electric Code to ensure you’re operating your generator safely and legally.