What Size Generator Do You Need to Power Your Home During an Outage?

When stormy weather arrives, power outages are more likely to occur. An extended outage can interrupt your family’s lighting, refrigeration, cooling, heating, and medical devices. 

By getting a generator, you can maintain your power during an outage. For the best results, your generator will need to be appropriately sized by an electrician. Otherwise, an incorrectly sized generator can cause overloads or leave your essential systems without power.

Start by Listing Essential Loads

Before you invest in a new generator, you first need to decide what it will be powering. Depending on your family’s health, comfort, and convenience preferences, you may need it to power the following things.

• Your refrigerator and freezer
• Important lights
• The internet router
• Medical devices
• Phone charging 
• Your well pump or sump pump
• The garage door opener 
• Heating and cooling equipment
• Your security system

Understand Running Watts vs. Starting Watts

Running watts are the watts needed to power the equipment while it is actually running. In comparison, starting watts are the extra power the equipment needs when it first powers on. Some devices, like refrigerators, compressors, pumps, and HVAC systems, require significantly more starting watts than running watts.

Your generator must be able to supply the starting watts you need and not just the running watts. Otherwise, a large device could trip the breaker, fail to start, or cause voltage changes that harm your sensitive appliances.

Small, Mid-Size, and Whole-Home Generator Options

The generator type and size you need will depend on what you want to power and the size of your home.

• Small, Portable Generators: This option works if you only want to power your basic essentials.
• Mid-Size Generator: If you want to power more circuits or appliances, you’ll need to upgrade to a mid-size generator.
• Whole-Home Standby Generator: A whole-home standby generator monitors your home’s electrical connection, so it can automatically switch on when the power goes out. In addition to automatic startup, it offers broader coverage for your home and is an excellent option for extended outages.

Before you can buy or install any generator, it’s essential to complete a load calculation. One of our electricians can handle the load calculation, so you can get an appropriately sized generator for your home.

Can a Generator Run Your HVAC System?

A generator is capable of running your HVAC system, but there are some important caveats to consider. Central ACs and heat pumps draw a significant amount of power. This means that you’ll need to have a generator with a larger capacity in order to power your HVAC system.

If you have ductless mini-splits, the power requirements will likely be different. You may also be able to reduce your power demand by limiting the equipment you use.

Because of the power capacity required, you shouldn’t just hook a generator up to your HVAC equipment. To avoid damaging your HVAC equipment and generator, you should check with an electrician to see if your generator can safely support the HVAC load.

Why Transfer Switches Matter

A manual transfer switch is set up to connect your generator to the breaker panel. It prevents backfeeding and is significantly safer than relying on extension cords.

Backfeeding is when the power produced by the generator goes backward into the utility lines. It is considered illegal because of how unsafe it is for any utility workers working on the lines. Additionally, backfeeding can cause explosions, fire hazards, and electrocutions, making it dangerous for any person or equipment in your home.

A transfer switch can be set up by an electrician so that you can plug your generator into an outdoor inlet when the power goes out. Then, you just have to flip a switch on your breaker panel to switch from utility power to generator power. 

Common Generator Sizing Mistakes

When sizing a generator, homeowners often make several frequent mistakes. By working with a professional, you can avoid these common pitfalls and safely power your home.

Forgetting Starting Watts

Your generator’s capacity needs to be enough to meet your running watt and starting watt needs. Many appliances pull extra power when they first start up, so you may need a higher capacity than you expect.

Using a Small Generator To Power an Entire Home

Portable generators aren’t intended to power an entire home. Initially, using an undersized generator can cause the generator’s circuit breaker to trip or the engine to stall. Eventually, overloading the generator can damage your appliances and cause the generator to break down. It can also lead to fire hazards, electrocutions, and backfeeding.

Overusing Extension Cords

Extension cords aren’t intended to be used for extended periods of time. When too much wattage runs through extension cords, it can cause melted insulation, overheating, damaged appliances, and fires. Installing a transfer switch is a much safer alternative.

Ignoring Fuel Type and Runtime

There are dual-fuel, tri-fuel, gasoline, diesel, propane, and natural gas. Even if you have a basic gas generator, the manufacturer likely requires a fuel stabilizer to be added to the tank if the generator will sit unused for 30 days. 

Similarly, the generator’s manufacturer will have specific rules about runtime. For example, portable generators are often limited to 8- or 12-hour runtimes. With a whole-home generator, you’ll need to check the oil every 24 to 72 hours of runtime, depending on the manufacturer.

Skipping Professional Electrical Review

The best way to ensure your electrical systems and generator are safe is by scheduling a professional electrical review. Our team can perform a load calculation and help you determine the best generator setup for your home.

When To Call a Licensed Electrician

If you are considering a generator upgrade for your home, we recommend calling a licensed electrician if any of the following situations apply. 

• You plan on connecting your generator power to your breaker panel.
• Your current electrical panel’s breakers trip frequently.
• You need a generator that can power your HVAC equipment, pumps, or medical equipment.
• You currently have an older electrical panel.
• You’ve remodeled or added home additions without increasing your panel’s capacity.
• You want to set up a whole-home standby generator.

Get Your Home Prepared for the Next Power Outage

Before the next power outage arrives, it’s important to make sure your Medford and Grants Pass home is prepared. If you are going to install a generator, you need to figure out the right electrical load for your needs. More importantly, you need the help of a professional electrician to ensure the generator is set up safely.

Schedule a generator consultation in Southern Oregon by reaching out to Rogue Valley Heating, Cooling, & Electrical today.