Generator automatic transfer switch
Generator automatic transfer switch

Many power systems use generators as backup electricity sources —and a generator interruttore di trasferimento automatico to reliably switch to the standby source. We wrote this post to shed light on the generator ATS: what it is, how it works, how to install it, and price. Also, how installing an automatic transfer switch for generator backup systems can benefit your business or organization.

What is a Generator Transfer Switch?

A generator automatic transfer switch automatically switches the power source of a system from the primary source to the backup generator, usually when there’s a power outage or other grid problem.

You can also use the generator changeover switch in a solar electrical system. In this application, your main power source would be your PV system and the generator standby source to power your loads and, in some cases, charge the batteries.

A generator transfer switch can be manual or automatic. Many electrical systems employ automatic switches for its many benefits. So, what is an automatic transfer switch for generator and what advantages does it offer?

Generator Automatic Transfer Switch

A generator ATS is an intelligent or self-acting power transfer switch. It continually monitors your primary power source. As soon as it senses an outage or other problems that precede outages, it will start up the backup generator and transfers the carico elettrico to it.

Once the utility power is restored and safely stable, the automatic generator transfer switch will safely return your electrical system back to the normal power source. It will also instruct your standby generator to stop. All these events take place automatically.

Using an automatic transfer switch for generator connection has several advantages:

  • A generator automatic changeover switch offers reliable, and safe power switching due to its autonomous operation.
  • Using a generator with automatic transfer switch ensures increased equipment uptime
  • Another major advantage of a backup generator automatic switch is enhanced safety for personnel and equipment. That’s because no one needs to go near the generator every time the primary power source fails.
Residential Generator automatic transfer switch
Residential Generator automatic transfer switch

How Does an Automatic Transfer Switch Work?

A backup or emergency automatic generator transfer switch is wired to your distribution panel, the generator inlet panel, and your loads. It therefore, can communicate with both the utility grid and backup generator.

With this arrangement, the ATS can intelligently switch your loads to either electricity source, depending on the health or availability of the primary source.

The generator transfer switch usually does not connect to the secondary source immediately. Instead, it first lets the generator build up speed and stabilize the voltage before it transfers the load. This prevents damage to sensitive equipment from fluttuazioni di tensione.

Home Generator Automatic Transfer Switch

A home generator automatic transfer switch powers your home in an outage or if using solar energy and the batteries are running low. It can be a whole house automatic transfer switch or a type that selectively powers specific circuits or loads.

Interruttore di trasferimento automatico per generatori RV

RV owners can install an automatic transfer switch to turn on the generator when the RV is not using shore power due to an outage. Also, when an RV solar system cannot power your loads. An RV automatic transfer switch saves you from having to manually start the generator each time.

Commercial Generator Transfer Switch

Some commercial and buildings have an emergency generator that kicks in automatically during a power outage. When the power goes out, the generator ATS switch senses the loss of power and signals the generator to start.

Industrial Generator Transfer Switch

Industrial generator transfer switches are used in a variety of applications, including data centers, hospitals, and factories. These switches are designed to handle large loads and can be customized to meet the specific needs of the application.

Generator transfer switch wiring diagram
Generator transfer switch wiring diagram

Generator Automatic Transfer Switch Wiring

A standby generator automatic generator typically has three sets of connections — one for the utility power supply, one for the generator, and one for the load. When utility power is available, the switch connects the load to the utility power supply.

When the utility power supply is lost, the switch disconnects the load from the utility power and connects it to the generator.

A generator automatic transfer switch is typically hardwired to the electrical system. It is important to consult with a qualified electrician to ensure that the generator auto transfer switch is properly sized and installed.

Can I Install a Generator Transfer Switch Myself?

You could. However, the generator automatic transfer switch installation process is mostly not a do-it-yourself project. So it’s best to leave the installation to a qualified electrician. Besides, you don’t want a wrongly wired device in your home of other place.

You also wouldn’t want to void the generator’s warranty by installing the switch yourself. Most building codes require a licensed electrician to perform the installation, too, for safety reasons. Therefore, unless you’re qualified and familiar with your local building codes, we recommend hiring an electrician.

Having said that, you may still want to understand what mounting a transfer switch for your backup power would entail. If that’s the case, the next section details the procedure.

Installazione dell'interruttore di trasferimento automatico
Installazione dell'interruttore di trasferimento automatico

How to Install Generator Transfer Switch

Here, now, is how to install a standby generator with automatic transfer switch. Note that your electrical system may require different installation steps and this is only a general guideline.

You may need the following:

  • Screw driver- to remove or install the various parts
  • Wrench- to secure wires/conduits
  • Hammer- to use with screwdriver for knockout removal

1. Start by selecting the proper transfer switch location. The switch should be located near the main electrical panel.

2. Mount the transfer switch. This may be indoors or outdoors depending on enclosure type.

3. Turn off power at the main breaker.

4. Determine and label the circuits or loads that you want to be powered by the standby generator.

5. Find a knockout whose size will fit the transfer the switch conduit at the service panel’s bottom.

6. Take out the knockout and carefully feed the conduit through the hole. Use a locknut to secure the conduit to the bottom of the panel.

7. Next, match these circuits with those of the transfer switch (the switch will usually come pre-wired).

8. Connect transfer switch wires to the appropriate circuits as selected in step 3.

9. Ensure all wires are secure and tight

10. Using screws, install the generator inlet box. Usually, the box is installed outside.

11. Connect electrical cable from the box to the transfer switch. Likewise, connect the generator cable to the electrical box and plug it into the generator.

12. Finally, turn on power at the main breaker and test your generator transfer switch by simulating a power outage.

If you experience any problems during a generator transfer switch installation process, or have questions, consult a professional electrician. Your generator’s or switch manufacturer may also offer helpful tips and instructions.

In some cases, you may need to install a subpanel near the generator to connect the generator to the automatic transfer switch. This is typically required when the generator doesn’t have enough power to run all of the loads in your home.

Generator Automatic Transfer Switch Price

When you’ve decided that you need an automatic transfer switch for home generator or business power system, the next step is to choose the right model. The price of a generator transfer switch varies depending on the features and capacity.

Basic models start at around $300, while large or more feature-rich models can cost up to $2,000. When choosing your home or business generator automatic transfer switch, be sure to consider the following factors:

  • The size of your generator
  • The number of circuits you need to connect
  • The type of automatic transfer switch connection you need
  • Any special features you may need, such as a built-in circuit breaker

Once you’ve considered all of these factors, you can narrow down your choices and select the transfer switch that’s right for you.


Utility power outages can happen at any time. A generator automatic transfer switch ensures that your home or business has the power it needs to stay up and running during such situations. By installing a properly sized and installed switch, you can rest assured that your home, business, or industrial facility will have the power it needs to keep things running smoothly, even during an outage.

Catalogo degli interruttori automatici di trasferimento IGOYE