The Ultimate Guide to Standby Generators

October 30, 2024 | Nate Cord

Standby generators, also known as backup generators, are a reliable backup power solution during a power outage. In this guide, we will cover all your most asked questions about standby generators, including how they work and what you need to consider when using one.

What is a Standby Generator?

A standby generator is a backup power system designed to provide electricity when the main power supply is interrupted. Unlike portable generators, which require manual setup and activation, standby generators are permanently installed outside your home or business.

Most permanent generators come with an automatic switch which, as the name suggests, will automatically turn on and supply backup power in the event of an outage. However, some standby generators will have a manual switch, which has to be turned on during an outage.

How Do Standby Generators Work?

A standby generator with an automatic transfer switch (ATS) is designed to detect when power is lost, which triggers the generator to activate and provide power.

1. The automatic transfer switch (ATS) constantly monitors your home or business’s power. When a disruption occurs, the transfer switch detects the outage, isolates your electrical system from the grid and transfers the power load to the generator.
2. Once the transfer switch is activated, the standby generator starts, delivering power to your home or business. This process usually takes less than 30 seconds. However, if your generator is powered with a manual switch, this can take longer (as you will need to go and turn it on).
3. When the main power supply is restored, the automatic transfer switch senses the return of grid power, switches off, and transfers the power load back to the mains. The generator then returns to standby mode where it awaits the next outage.

Benefits of a Standby Generator

Power outages can occur for several reasons, including severe weather or grid failures. The main benefit of a standby generator is that it ensures your home or business remains powered in the event of an outage. For generators with an automatic switch, this all happens—without any manual intervention—within seconds. This has several advantages, including:

• Continuous power for essential systems: Your heating and cooling system, refrigerators, medical equipment (such as ventilators or dialysis machines), and security systems remain active.
• Peace of mind during emergencies: If you live in an area that is prone to natural disasters, storms or unexpected grid failures, a standby generator will keep you powered.
• Less food waste: If your refrigerator or freezer is without power for too long, your food will go off. For homes and businesses, this can be costly and dangerous in the event of emergencies. However, a generator can prevent food waste by keeping appliances powered.
• Long-term solution: Standby generators can be a better solution than portable generators for homes and businesses that require regular and long-term power over infrequent and short-term power.
• Increase resale value: Having a standby generator installed can increase your home’s resale value, especially in areas prone to power outages.

How Long Can a Standby Generator Run?

The type of engine in a standby generator will determine how long it is designed to run. Generators with a 3000 rpm engine are designed to run for up to 12-16 hours before they will need to be shut down for cooling and rest so they can be run again if needed. Generators with a 1500 rpm engine, on the other hand, can run for several days without stopping.

However, the runtime of a generator also depends on the fuel source and capacity. For diesel generators, the onboard fuel tank can limit the run time, but the larger units with a 1500 rpm engine can be connected to an external fuel tank with greater capacity to allow for several days of running if needed. Gas generators with a 1500 rpm engine can also be used for longer periods (several days) if supplied by either a large enough tank (LPG) or connected to a mains supply (Natural Gas).

Can You Use a Standby Generator Full Time?

No, you should not run a standby generator full-time, but you can use it for several days during a power outage. With proper maintenance and fuel, some models can even run for weeks at a time. However, they should still be treated as a temporary solution rather than a permanent power source.

If you need continuous power for off-grid living or long-term needs, a continuous – or prime power generator – is recommended. Diesel generators are the most common full-time generator option as they are robust and designed to handle continuous, heavy loads.

How Often Should a Standby Generator Be Tested?

Some modern standby generators come equipped with an automatic self-testing feature. This feature runs the generator for a short time— about 10-20 minutes—once a week to ensure that it’s operational. However, in addition to self-tests, you should test the generator once a month. It is recommended that, twice a year, you have a professional inspection and service of your generator. We recommend a minor service at 6 months and a major service at 12 months.

If you live in an area that is prone to storms (or natural disasters), we recommend that you perform additional tests before the storm (or season) begins so you know you’re prepared in the event of a power outage.

Does a Standby Generator Need a Ground Rod?

Yes, in most cases, a standby generator requires a ground rod as part of its installation. Proper grounding ensures that the electrical current is directed into the earth in the event of electrical faults, surges or lightning strikes, rather than through appliances or structures. Always consult a qualified electrician or generator installer for specific earthing requirements for your property.

Do you have another question or require additional advice? Don’t hesitate to get in contact with our experts using this form or via phone at +441639849847.

Looking for a quality generator? At Generators Direct, we offer a range of generators, power stations and power banks for your specific needs. All of our products are manufactured, tested and certified to industry standards, and come with a price promise – you won’t find prices cheaper anywhere on the web, but if you do, we’ll match them. In addition to this, all orders come with free mainland UK shipping and after-sales support from our experts.