How to Safely Wire a Generator to a Breaker Box?

A generator is your best friend when the lights go out because of infrastructural problems, storms, rain, or natural disasters. If you have a standby generator, it is always wired to your home’s electrical system. In contrast, a portable generator needs to be connected with the electrical panel using a transfer switch. A Transfer switch converts the source of electricity from the mainline to the generator and vice versa. Some people may argue that you can use a generator with an extension, but it is not safe and practical when using it to power your house. You can use extensions when using a portable generator outdoor.

Benefits of using a Transfer Switch

In addition to being safe, a transfer is switch is required by law to wire a generator to your home. Skipping it can be catastrophic not only for your home but also for the electric infrastructure. If your generator back feeds, an electrician working on the poles may get electrocuted. The following are the benefits of using a transfer switch along with a portable generator.

  • A transfer switch is safe and prevents back-feeding.
  • It is a hassle-free way to power your home. It also gives you the freedom to connect furnaces, air conditioning units, well or sump pumps to your home through the breaker box.
  • Transfer switch makes power management easy. It gives you the freedom to on/off the devices you don’t need at a particular time, such as a furnace, pumps, and ACs.

Types of Transfer Switches

Manual Transfer Switches – They are commonly used in the majority of American households. They are necessary, practical, and economical. As the name suggests, you have to turn the load on the generator from the mainline manually. Manual switches come in various models with up to 16-18 circuits at one time.

Automatic Transfer Switches – If you are looking for a hassle-free solution to convert from utility to generator, you need an automatic transfer switch. These switches are programmable and manage the connections according to the instructions given. They prioritize the relationships you want to run first. It is also capable of converting the power back to the mainline once a blackout ends. Some models come with the feature to manage a UPS connection as well. Automatic transfer switches are commonly used in hospitals, banks, prisons, and police stations.

Interlock Kit – Interlock kits are the cheapest of all the options. They are easy to install but are not legal in many states; there’re some circumstances where their use is acceptable. It can back-feed and create some serious issues.

Now that we know the basic things about the transfer switches let’s learn how to connect the generator to your home with a transfer switch.

How to Safely Wire a Generator to a Breaker Box

Tools Needed

  • Electric Wire
  • Generator Cord
  • Transfer Switch
  • Tool Kit
  • Drill Machine
  • Inlet box (recessed male connector)

Measure the generator's distance from transfer switch

Step 1: Measure the Wires Needed – You will need to measure the cables from the generator’s point to the inlet box. It will be the generator cord and is readily available online and in electric stores, or you can make one on your own. The second wire would need to reach the transfer switch from the inlet box. Installing the transfer switch adjacent to the central electrical control of your home is the most appropriate.

Step 2: Install the Inlet Box – Install the inlet box at the marked point. You would need to screw it in the wall, and you would need a drill machine for this. You can use it to plug-in the generator. A safety tip: installing a shade for your inlet box will help keep it safe from sun and rain. The best place for installing an inlet box is the outer wall of your home. It will be the wall where the electric control panel is installed in your home. This setup will help you save a lot of money as you won’t have to buy huge lengths of wires.

Step 3: Install the Transfer Switch – Now install the transfer switch at the designated place. Fix the nuts tightly and check it is correctly installed. Refer to the instruction manual of the transfer switch for detailed instructions on installation.

Step 4: Wire the Systems – The exact type of wire you needed should be mentioned in the transfer switch’s user manual and your generator. Don’t go for any other wire. Make sure it can handle the loads you are planning to put on it. While you are wiring, you need to be very cautious with the color of the wires. The black wires carry the current and must be connected with the black. The green is protective ground and must be wired with the green connector and white (neutral) to the white connector. If you are NOT COMFORTABLE dealing with wires, you must call a certified professional to do the installation for you.

Step 5: Connect the Circuits on the Transfer Switch – If you have a transfer switch supporting circuits, connect them with the primary circuit’s respective appliances. Similarly, you can also connect room breakers to the transfer switch. These are technical things and require experience and vast knowledge. If you lack in these two areas, do not interfere with the wiring. Please make sure that while you are working with the home’s main electrical panel, the main supply is switched off.

Step 6: Check The Transfer Switch – It is time to check the transfer switch without turning on your generator. Turn the switch from the main supply to the generator. If you have installed the button correctly, the lights will go off. If they flicker or fluctuate, there is some fault in the installation.

Step 7: Checking the Entire System – After you have correctly installed the transfer switch and connected the wires, it is time to check the entire system and see what you have achieved. Please turn on your generator; click it to the inlet box, and convert the transfer switch from utility to generator. Ensure that all the circuits on the transfer switch are off. Once you see the indicator light going on in the transfer switch, pat yourself on the back. You have succeeded. Now turn on the appliances one by one to check their operation. Please don’t turn on everything at once, as it will overload your generator. While checking the system, you must keep in mind that how you have managed the load. What are the occasional things, and what are the always-on appliances on your generator. Installing a transfer switch does not mean that your generator’s capabilities have been enhanced.

Check the inlet box and make sure there are no sparks or smell coming from it. Similarly, check the wires and transfer switch for any smell, sparks, or anything out of order.

Step 8: Professional Inspection – Once you have inspected the setup, it is time to get professional advice from a licensed electrician. They will visit and check every connection, voltage, output, safety measures and rectify anything out of order. It is essential as you can violate the insurance agreement of your home by making connections yourself.

Final Word

Installing the transfer switch as a DIY project will save you a handsome amount of money, but it is a risky thing to do. Not only you, but your family, your appliances, and your entire home are also at risk. Don’t do it if you are not aware of electrical connections, managing generators, and laying up wires. We suggest that you take all the safety measures while working with electricity and call a certified electrician immediately if things get out of hand.

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