How To Install A Backup Generator – Installation Guide

Have problems with power outages? You can easily solve them by installing a stand-alone generator. Today we will talk about the choice of a generator and the rules for installing and connecting it to a home electrical network.

Why do you need a backup generator?

Many homeowners purchase small power generators for backup power at times of power outages. A backup generator is simply an alternate source of electrical power in case of a power outage.

Fluctuations in the power supply can be detrimental to many home appliances. A backup generator will keep power in your home running, including your home security system.

Modern generators have the potential to run periodic self-checks to diagnose any potential issues.

The main goal in installing a generator for your home is to have the peace of mind that you and your family will be safe in an emergency if the power goes out.

Reasons to use a backup generator:

When there is a power outage or a natural disaster, such as a hurricane, heavy ice, or snowfall, generators are a piece of essential safety equipment to have in your home.

If there are life-saving medical equipment or important devices, that need the power to function, then installing a backup generator goes without saying.

An emergency generator can be a backup power source that temporarily provides electricity in the event of a power outage. It can provide light, heat, and electricity until the facility is restored.

Standby generators automatically turn on when the main power supply is turned off; therefore, it should be noted that portable generators, which also provide emergency power, must be operated manually.

What is the difference between an automatic standby generator and a backup generator?

A backup generator can also be referred to as a portable generator but does not run automatically when the power goes out.

The standby generator derives its name from what it does literally; automatically taking over in case of a power outage.

For example, if you take a shower during a power outage when the air conditioning is running, the good pump that supplies water combined with the air conditioning could overload the unit.

Your generator will be programmed to know that the well is more important than the air conditioning.

How much power is needed to operate backup generators?

The amount of power required to run a backup generator is an important piece of advice you should consider when purchasing and installing a backup home generator.

It takes about 5,000 watts to power an average home, so you need to buy a generator within that capacity to prevent a power outage and its impact on your life and electrical appliances.

If you decide that you would like to have air conditioning in a power outage, then you would be looking at a generator, usually close to 20kW.

The more power is used, the more fuel the generator consumes. This is especially important when propane (LP Gas) or diesel fuel from an on-site storage tank is the fuel source.

Prior steps of a backup generator installation

Choose the type of generator you wish to be installed. This is vital, so do some background research on the various types and models of generators.

When choosing a generator, you need to think about its installation plan in advance. At the same time, it is worth considering several nuances that it is important to pay attention to.

Obtain the needed permits. This is unarguably the most important step before committing to installing a standby generator or a backup one. Every local governing authority has different pre-installment requirements.

A local inspector from your jurisdiction will likely need to approve your installed generator to ensure that it meets all required safety standards.

Read more information to consider before installing a generator, which could make generator installation a job that’s best left to the professionals.

Hire a professional installer and other specialists. Installing a generator isn’t a straightforward job anyone can do.

Unlike changing the oil filter in your car or tiling the spare bathroom, home generator installation includes electrical wiring, plumbing, and natural gas components.

The plumber will connect the gas line, and the electrician will have to install an automatic transfer switch (ATS) to start the generator when it detects fluctuations in shutdown.

Your gas technician should work with your electrician, to ensure that the gas line and electrical line are in the same trench but not installed in the same vertical plane.

Main steps of a backup generator installation

Firstly, regardless of the chosen home generator – a natural gas-powered generator or a diesel one – the basis of its design is the engine.

If you’re using natural gas or LP gas to power your generator, you’ll need to connect the natural gas line or propane tank to the generator.

The products of portable generators are exhaust gases. Thus, it is not recommended to place a home standby generator indoors.

There is also the risk of carbon monoxide poisoning from the engine exhaust.

In the case of installing a standby generator outside the house, it is also important to consider the ventilation through which unwanted gases will flow. Garages and various outbuildings are mainly the places of standby generator installation.

Secondly, there are two principles for launching standby generators: manual and automatic.

Thirdly, standby generators equipped with a remote control system have become popular recently. To purchase and install such a backup generator, you need to additionally purchase a GSM module.

Finally, for the correct installation of a standby generator, it is important to solve the issues of laying and connecting a backup cable that will connect the generator to the control board of the house.

How to install a backup generator – mandatory stages

Securing the backup generator to the concrete pad

The standby generators can move and shift the ground due to vibrations when it is on, so they should be secured to your level concrete pad.

A home generator must be secured to the concrete pad with stainless steel bolts.

Connection of the fuel line

The four fuels that are primarily used for generators — are gasoline, diesel, LP gas, and natural gas. While gasoline is the most common fuel for a portable generator, it’s a poor choice for whole-house generators. 

A plumber will install the tubing connecting a standby generator to the fuel source, whether it be propane or natural gas.

How to install a natural gas backup generator

A natural gas-powered generator can power your home for days or even weeks because it is directly attached to the fuel source. It will be hooked up to a natural gas meter.

Installing the transfer switch

Transfer switch senses when the power goes out to switch the power source to standby generators automatically. They come in different sizes and specifications and can be installed ahead of an electrical panel or after the main panel, controlling a small sub-panel.

A transfer switch is installed beside the electrical meter; it transfers electricity into the house when the facility goes out and therefore the generator kicks on.

After installing the transfer switch, the electrician will connect the standby generator to your home’s electrical system.

The installation process of a standby generator

There are several schemes for connecting standby generators: to the machine, through an outlet, or a switch. It is necessary to take into account the launch method (manual, automatic transfer switches), and the phase of the device.

Electrical knowledge is required to connect the standby generator to your existing electrical system.

“Fast” emergency socket connection

Plugging into an outlet is the fastest way to connect the generator to the mains at home in the event of a power outage. For this purpose, you will need a cord with two standard plugs, often it is made independently.

You can take spare parts from unusable cables, electrical appliances, and extension cords or buy collapsible plugs and wires.

If a standby generator for a house is up to 3 kW, then overload, leading to overheating, ignition of cores, insulation, and circuit elements, is not terrible.

Danger due to accidents, forgetfulness, ignorance of the rules

Before turning on standby generators, it is necessary to turn off the introductory (fire) automatic switch; otherwise, the power will go to other lines, to the neighbors, and the standby generator will stall from overloads.

Application of protective devices, polarity

When installing the wires of the home network, they are connected to the automation without taking into account the polarity, but when they are already connected, the order may need to be observed for some devices, including a backup generator.

The source cores are connected to the upper terminals of the protective shutdown device, and the load wires are connected to the lower ones.

In some models (especially electromechanical ones), you can swap the top and bottom. But still, it is advisable to always adhere to the usual order to avoid confusion.

Connecting the home generator to the network in this way involves tracking the phase and zero, otherwise, only the near sockets may function, and when the devices and bulbs are powered, the protective shutdown device will snap off.

If at the same time it is necessary to make changes to the network, then it is too labor-intensive, so the solution to the problem is one – installation of a direct connection through a switchboard.

It is advisable to immediately choose this method, rather than connecting to a regular outlet. They are connected through group machines, and not through the introductory auto-switch in front of the metering device; otherwise, it will count the money for our generated resource.

Inability to monitor the main electricity

When using an outlet, it is impossible to monitor the resumption/disappearance of the main (trunk) power supply to turn off/turn on the unit promptly.

Usually, a warning light is used for this, but in this situation the introductory auto-switch is disabled, so it is impossible to use it.

Via an automatic (distribution) switch

There are stations that are equipped with automatic service. The automatic unit is connected to the generator and to the mains.

When the power goes out in the house, the generator system automatically kicks in, replacing the main power source. When the power supply is restored, the station also switches itself off.

Such a unit can be purchased separately from electrical stores.

The principle of automatic transfer switch (ATS) connection: the ATS system is connected to the mains; ATS and generator connect the control cable; a cable comes out of it, which is attached to the contacts of the generator and conducts electricity to the house from it.

Through a swing, a reversible transfer switch

This is the same option with switchgear, a three-position switch is already being added to the circuit, and it is mounted permanently.

A transfer switch of this type implies that current can be supplied to it from 2 different branches when a load is connected to one. The middle position is neutral to exclude the closure of incoming wires.

This scheme is very popular, it is chosen for portable generators if there is no desire to spend money on ATS.

If there is no factory 3-position switch, then you can assemble a temporary version, and a two-position swing design of two 2-pole automatic switches is also suitable. It is advisable to take devices from the same manufacturer, identical in face value and size, so it will be more convenient to connect them.

The devices have a “jack”: one is inverted. The keys are fastened together, for this purpose, the manufacturers make holes for pins on them, the role of which you can use a thick rigid wire, or a paper clip.

Thus, the “fool protection” will be triggered immediately: one automatic switch is turned on, and the second one is turned off at the same time.

It is possible to build the described device from 4 single—pole automatic switches – the principle is identical. You can also not turn them over, and switch each one separately, but there will be no “fool protection”, which is dangerous for an uninformed person.

The automatic transfer switch can be mounted anywhere on the line, but it is most expedient to install it near the generator since the start is carried out in a certain order.

To prevent the portable generator from idling when the main voltage resumes, they make a tap for the alarm at a noticeable position. And when you connect it through the automatic transfer switch, it will not light up all the time.

How to make a simple auto-switching circuit for a generator

It is always inconvenient to switch the circuit breaker when starting the backup unit, so a simple automatic transfer switch is assembled.

This is not an autorun system, its task is a mechanical change of input between the backbone networks and the mini—station. Starting/silencing the motor still needs to be done manually.

The generator tests itself automatically by turning on every period and running for about 20 minutes.

Automatic autorun of the backup generator

If you have the skills, you can implement a scheme that automatically starts a gasoline generator when the network is de-energized. Use a backup station model with a start/stop key.

For a product with a starter, when it is necessary to pull the cord, theoretically this can also be done, but this option is too complicated, it is not worth the effort.

Automatic start via the ATS unit

The simplest and most popular way out when solving the question of how to connect a power supply generator with automation is to use an ATS (Automatic Transfer Switch).

These are special control boards with automation specifically for autonomous sources of electricity. The devices are also called switching units, and docking stations.

They are usually mounted near the flap or in it, they resemble it in appearance as standard. They are connected like an automatic switch after the counter, before the automation of the lines that will power the generator. There are two device modifications.

The first type of ATS completely repeats the auto-switching system, inside the same 2 starters, relays, etc., an electronic start/stop unit has been added to the circuit.

A low-current wire is brought from the main line to the node, through which information about its condition is received on the ATS, and the unit reacts by giving a start/ stop command. The main line and reserve are replaced by starters.

This is the same scheme as described above, but factory. The disadvantage is the same — there is no protection from emergencies.

The second option is more perfect: a complex system with microprocessor control, and advanced electronic stuffing (chips, controllers). The main tasks and the algorithm of operation are the same, but there are several sensors in the composition that control the operation of the generator.

Protection against all possible emergencies for this device has already been implemented here. The ATS will not be tormented by attempts to autorun, if there is a GSM module, it will send a notification of breakdowns to a mobile phone.

The connection is simple: wires are connected from the mains (after the meter) to the AVR, from it to the generator — power and control cables, as well as output to the house.

ATSs are expensive, especially with microprocessor control, sometimes their price is compared with the cost of a generator, so such a purchase is more justified in cases of frequent power outages and for powerful mini-stations.

The connection of the gas generator is single and three-phase

The connection scheme of a three-phase power supply generator to a house, or cottage, in the presence of the same network, implies similar connections as with a single-phase system.

The only feature: it is necessary to make more connections since in this case, the number of wiring cores is increased.

There is an important caveat: if you use a starter, then its contacts are designed for power wires, they are not enough for the coil, and you need to decide where to get power for it.

Connecting a single–phase generator to the same network does not have the described complexity – there is only one phase, and such a question simply does not arise.

Everything is more complicated with three phases. In short, the solution is simple: for the control circuit, it is permissible to take any of the phases, but only one.

Connecting a single-phase generator to the three-phase network of the house is also possible. There are many schemes, but the simplest one is this: a parallel combination of 3 phases and a connection to phase 1 of the power plant. At each phase, the load will be distributed evenly.

Selection guide: it is necessary to buy a three-phase generator if there are one and three-phase consumers in the house at the same time, which often happens in private housing. Usually, there is a 380 V and 220 V outlet on the product, that is, two types of devices can be plugged in simultaneously with it.


It is necessary to ground the backup source — a static charge occurs on the housing. You will need to build a separate grounding circuit.

Ideally, if it is possible to create a full-fledged design, a simple method will also work. You will need a 1.5–2 m metal rod, a bolt or clamp (metal), and a soft copper wire (large cross-section from 4 mm2).

The vein is attached with a clamp to the pin or they weld a bolt and attach it to it. The rod is driven into the ground, and the other end of the wire is fixed to the generator housing.

Installation of transfer switches

A switch isolation is used to isolate a home’s power supply. All of the circuits remain untouched to reduce the chances of overload. The switch is electrically isolated to isolate generators and homes from the grid.

This blocks electrical energy to return to the system. It helps prevent fires and utilities from being injured while doing repairs to put out power.

The switch prevents homes from running on electric power when the generator is running, which could trigger electrical fires or the generator could catch fire.


Theoretical knowledge is good, but don’t apply it without a professional specialist, especially when you deal with electricity, and natural gas. Wonder how to backfeed a breaker panel with a generator, read.

Frequently Asked Questions (FAQs):

Can You Install A Backup Generator Yourself?

No, you can’t. It’s not an easy job! It is risky. It requires a specific set of skills and although you would possibly have done some research on how to install backup generators, don’t do it yourself.
Moreover, you will need to contact an accredited gas installer if your power source needs to be connected to natural gas or propane connection.

How Do You Hook Up A Backup Generator To Your House?

Plugging the generator cord directly into a power supply can be simple.
It divides up into several outlets that allow you to securely connect additional extensions inside your house. But this method is not safe to use.

Can I Buy A Generac Generator And Install It Myself?

Generac offers a variety of Guardian Series System packages preassembled with comprehensive instructions for installation.
You could perform the simple site planning steps and ask for a specialist to install the electrical panels and fuel connections, or you could carry it out yourself.

How Much Does It Cost To Install A Backup Generator?

Installing a backup generator costs $4 818 on average, or between $1 448 and $8 190. You have various options to choose from, including whole-house, partial, standby, backup, and portable generators.
For example, installation of a backup generator may cost $3000 – $6500. This includes technical work needed in the installation of a backup generator at your house.
Labor, circuits, transfer switches, and concrete pads make up around $500 to $5,000 of those prices.

Leave a Reply

Your email address will not be published. Required fields are marked *