A portable generator is a simple and inexpensive option for keeping your lights and appliances running when the power goes out to your house.
There are two ways to keep your house powered with your generator: (1) by connecting appliances directly to your generator, or (2) connecting your generator to your house’s electrical grid.
The first solution – using extension cords to connect your appliances to your portable generator outside – is cumbersome at best. And during extended outages, there’s no way to plug your home’s lights into the generator, so you’ll be left to rely on flashlights and lamps.
Connecting your generator to your home is more versatile since you can use any appliances in your home as you would normally as long as you don’t exceed the power supply of your generator. All of your electrical outlets and lights will run just as they did before the power outage.
But, portable generators don’t come ready to connect to your house’s electrical grid.
Plugging a generator directly into a wall socket, which is known as backfeeding, can severely damage your home’s electrical wiring and even cause a fire. It’s also illegal, since backfeeding power into your home can actually electrocute any technicians who are working on electrical lines elsewhere on the grid.
SERIOUSLY – NEVER BACKFEED!
Instead, you’ll need a device known as a transfer switch to safely hook your generator up to your home.
Use a Transfer Switch to Connect a Generator to Your Home
A transfer switch is an electrical control device that you install directly alongside your home’s circuit breaker box. The main purpose of the transfer switch is to switch your home’s electrical grid off of the utility electrical grid and onto your generator.
The other use of a transfer switch is to make power management easy. The transfer switch acts much like your home’s circuit breaker, allowing you to load different rooms, outlets, or appliances on different sub-breakers. You control which outlets are on which sub-breaker when you install the transfer switch.
To control the amount of wattage being drawn from your generator, all you have to do is turn one breaker on and another off. That way, you can keep your entire house plugged in to the generator, but only draw power when you need to use a particular appliance. Ultimately, this allows you to use a smaller portable generator to power your home.
Manual vs. Universal Transfer Switches
There are two different types of transfer switches commonly available: manual transfer switches and universal transfer switches.
Manual transfer switches work much like a traditional circuit breaker box. To turn one set of appliances on or off, you simply flip the corresponding breaker.
Universal transfer switches automate this process. You can designate which outlets and appliances have priority, and the transfer switch will automatically turn breakers on and off to keep the total power draw below your generator’s maximum rated load.
Universal transfer switches are also helpful because they will automatically detect when the utility grid’s power fails and switch over to the generator. Some transfer switches even include a battery backup that can keep appliances running until you can turn your generator on. Similarly, universal transfer switches will automatically switch your home back onto the electrical grid when the power comes back on.
Installing a Transfer Switch
Installation of a transfer switch is generally done by an experienced electrician, since it involves moving around the wires that enter your home’s circuit breaker board. However, installation can also be done by homeowners with some experience with electrical wiring and most transfer switches come with clear installation instructions.
The most important step in installing a transfer switch is identifying which circuits from your main circuit board will be moved onto the transfer switch’s circuits. This determination will depend on which appliances you want to run during a power outage and the size of your generator. If you have a universal transfer switch, you’ll also need to program in the priority levels of different appliances.
Connecting Your Generator
You’ll need a specialized generator cord to connect your generator to the transfer switch. This cord plugs into the outlet on your generator and to the inlet on your transfer switch (like this).
To be prepared for an outage ahead of time, it’s possible to leave your generator connected to the transfer switch all the time. Otherwise, since you’ll be moving around in the dark during an outage, it’s a good idea to keep the generator cord located with your generator or transfer switch.
Before starting up your generator, flip the main breaker on the transfer switch so that it is drawing power from the generator inlet rather than from the utility electrical grid. Also make sure that all of the breakers on the transfer switch are turned off at this time if you are using a manual transfer switch.
Make sure that your generator is outside or in a well-ventilated area, then start it up. Now, you can turn on breakers on your transfer switch one at a time to power up your home.
When the outage ends, simply reverse this process. Remember to turn off all of the breakers in a manual transfer switch so that they’re ready to go when the next power outage strikes.