A backup generator can be a great addition to your home. Having your power suddenly go out can be a major headache. If the power is only out for a few hours, it usually isn’t a huge deal. However, if the blackout lasts longer, all of the food in your refrigerator and freezer can spoil and you won’t have any way to heat or cool your home. Backup generators overcome these issues by ensuring your home stays powered no matter how long the blackout lasts.

How Does a Backup Generator Work?

Unlike portable generators, backup generators are permanent units that are connected directly to your home’s electrical system. The generator is wired to your electrical system via an automatic transfer switch that connects to your main breaker panel. This allows the generator to constantly monitor whether the building has power.

The automatic transfer switch is the primary control for the system, which can instantly change between normal power and the generator. If this switch detects that the power has gone out, it will signal the generator to start. The generator will turn then automatically turn on within a few seconds. Once it is running, the automatic transfer switch then kicks in and switches your electrical system over to the generator.

At the same time, the transfer switch insulates your home’s electrical system from the local electrical grid. This prevents the generator from being overloaded when the power comes back on. It also prevents the power from the generator from flowing back into the electrical grid, which could be hazardous for any utility workers attempting to fix the power outage.

When the power comes back on, the automatic transfer switch signals the generator to shut down. Once the generator is off, the transfer switch changes back to normal power.

The generator itself can be powered by propane or connected to your home’s natural gas lines. There is really no difference between the two in terms of how the generator works. If you decide to go with propane, you will also need to have a large storage tank installed if you don’t already have one.

Exercising Your Backup Generator

Backup generators need to run for a few minutes every week or so. This is known as exercising your generator, and it is vital for its health. The main purpose of exercising is to ensure that the generator is functioning as it should. However, it also works to ensure that all of the parts are lubricated and prevents moisture from building up inside the generator and causing damage.

The control panel on the generator allows you to schedule the specific day and time for the generator to exercise. It is always best to schedule this at a time when you know you will be home. The point of exercising the generator is so you can make sure it is working properly, so you will obviously want to monitor it during this time. Specifically, you’ll want to make sure that the engine sounds normal and that the temperature and oil pressure are where they should be. You should also check for any leaks and make sure that no alerts or alarms are showing.

When the scheduled time comes, the generator will automatically turn on just as it would if the power goes out. However, when exercising, the automatic transfer switch does not activate. This means that your home will still be running off normal power and not the generator.

Most manufacturers recommend that you exercise your backup generator every week or two, but some units may only need to be exercised monthly. It is always best to follow whatever the manufacturer’s recommendations are. In this way, you can be assured that your generator will be working properly and ready to go whenever the power goes out.

How to Know What Size of Backup Generator You Need

If you’re considering adding a backup generator to your home, it is important that you choose a unit that supplies enough power to run all of your most important systems and appliances. The main thing to think about when sizing a generator is your HVAC system since this typically uses much more power than anything else in the house.

Backup generators range in sizes between 5 and 50 kilowatts (kW). If you want to make sure you have air conditioning during a blackout, then the size of your AC unit will determine the minimum size your generator needs to be. If you have a 3-ton AC unit, you’ll need a generator that is at least 12 kW. For a 5-ton AC unit, you’d need at least 20 kW. However, it is important to note that this is the bare minimum and may not still be able to power all of your appliances, systems and devices at one time.

Understanding Load Shedding and Load Management

If too many things in your house are calling for power at one time, it will overload the generator and cause it to shut down. Most backup generators use processes known as load shedding and load management to prevent this problem. Load management is essential as it prevents everything in your home from attempting to power on at the same time, which would typically overload the generator unless it has an extremely high capacity.

When the generator first turns on, it prioritizes those appliances or systems that use the most power first. This is typically your air conditioner or HVAC system. When your air conditioner first turns on, it requires far more power than it does when running. This is referred to as surge wattage, which is the extra power required on start-up. As soon as the AC is fully running, its power usage drops back to the normal level. At this point, the generator will then begin to power other lower-priority, lower-wattage appliances and systems.

Load shedding is when the generator automatically shuts off power to these lower-priority appliances whenever more power is needed elsewhere. For instance, if your AC shuts off and then needs to turn on again, the generator will take power away from other appliances to ensure that it can handle the AC’s surge wattage without overloading. Most backup generators allow you to manually select which loads to prioritize and which loads to shed when needed.

If you want to make sure that you have enough power to run all of your home’s electrical systems and devices at the same time without any load shedding, the only option is to purchase a higher-capacity generator. In this situation, you would need to make a list of every single appliance, system and device you want to be able to use during a power outage. You can then add up the total wattage of everything on your list to determine exactly how many kilowatts of power you will need.

Backup Generator Installation and Services

AJ Danboise Plumbing, Heating, Cooling & Electrical specializes in installing backup generators in Farmington Hills and the Greater Detroit area. Our licensed electricians have years of experience and will first perform a load calculation to determine exactly what size of generator you need. We can also help you with programming the generator and prioritizing loads if needed. Our team also services and repairs any existing generator. If you have any questions about our generator services or want to schedule a consultation, give us a call today.

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