Increasingly severe weather events coupled with aging energy infrastructure means it's crucial to prepare for power outages and lengthy restoration times with reliable backup power, such as a whole-home generator. It's important to note that all generators are not created equal, especially when it comes to powering up critical household appliances. To ensure all necessary equipment gets powered on, and appliances continue to function effectively and last for years to come, you will need to choose the best generator that will fit your household needs.

 

Like the engines of an aircraft that need extra power to take off, household appliances also require a greater initial surge of energy to start. This is called motor starting. In order for motors to move, a surge of initial power is required, which is measured in kilovolt-amperes (kVA). Having a good understanding of how motor starting affects the output of your generator and the longevity of your appliances will help ensure that you can maintain their functionality and longevity for decades to come. In this article, you will understand the specifics of how motor starting affects your home appliances and why choosing the right generator for your needs is so important.

How do appliances use motor starting power?

Have you ever wondered how your appliances get that initial burst of power to start up? It's all thanks to the motor starting power. Motor starting is the initial burst of power that is required to start the motor of an appliance, also known as the surge power. Power surges of this magnitude are considerably higher than the power that is required to keep an appliance running on a regular basis. The proper functioning of devices like refrigerators, air conditioners, and washing machines requires an initial burst of energy to turn on. It's this motor starting power that ensures their efficient operation from the moment they are switched on. Approximately two to three times the rated running wattage of an appliance is needed to make it start.

 

Example of Running Watts vs Startup Watts

Running watts vs starting watts

Appliances and their initial surge requirements

power current graph

You will want to be confident that your generator can handle the initial surge of power required for smooth and efficient appliance operation. Suppose the generator fails to meet this demand. In that case, appliances may struggle to start or operate inefficiently, potentially damaging the generator and increasing wear and tear on appliances. The Journal of Electrical Engineering highlights the importance of considering inrush current when selecting backup power solutions to prevent operational issues and equipment damage. Understanding inrush current is important when choosing the best generator for your needs. 

Understanding the initial surge requirements, or inrush current, of appliances is key to 'right-sizing' your generator. This is the amount of power an appliance needs when it's turned on. For example, a refrigerator compressor needs a significant power surge to start the cooling process and keep it running. The Electric Power Research Institute (EPRI) found that appliances requiring motors to start may need up to seven times the regular operating current during the initial start-up phase. The International Electrotechnical Commission (IEC) even states that the inrush current of electric motors can be up to ten times the running current according to its standards.

Understanding the kW to kVA Formula

In a perfectly efficient system, kW = kVA, but since systems have inefficiencies, this measurement tells us how much power is being used in a system overall. 

 

kW is the actual power

A kilowatt (kW) measures how much power an appliance consumes on average during use. For example, a television that uses 1,000 joules (units of work energy) per second consumes one kilowatt of power.

 

kVA is apparent power

The Kilovolt-Ampere (kVA) is a unit of apparent power that includes both voltage and current to determine apparent, or evident, power. Unlike KW, the kVA measures a circuit's total power, which includes both an electrical circuit's active and reactive components. This helps us understand just how much power a generator is capable of handling, especially when it comes to starting motors.

 

The kW to kVA Conversion

Converting kW to kVA involves subtracting the apparent power (kVA) from the actual power (kW) and the power factor (pf). The apparent power (kVA) is equal to the power factor (pf) of the actual power (kW).

 

If the Power Factor > 1kW = kVA × PF

If the Power Factor = 1kW = kVA

 

Power Factor (pf)

Consider the power factor as a measure of the efficiency of how electricity is used, and you'll see its impact on energy savings. It's the ratio between the apparent power (kVA) and the real power (kW). A power factor close to 1 indicates efficient power usage. For example, an appliance with a power factor of 0.8 can use 80% of the power it is supplied with, while the remaining 20% is lost to inefficiencies as a result of the power factor. By improving the power factor, you can significantly increase energy savings and reduce the load on electrical systems, which should motivate you to take action.

What happens if a generator doesn't have enough motor starting power?

A generator that does not provide adequate starting power can lead to a number of problems, including. 

 

1. Failure to start

A power outage can lead to appliances shutting down. Having the wrong generator without enough power will keep appliances out of use, defeating the purpose of having backup power. To choose the right generator with the right size, consider the total wattage of the appliances you want to power and add a safety margin of 20-30%. This will allow seamless power to engage appliances and continue running through a storm. Having the wrong generator can cause appliances to not start at all, which can cause inconvenience to your household.

 

2. Inefficient operation

In some cases, appliances start but don't operate efficiently, resulting in poor performance and increased energy consumption. For instance, an air conditioner that struggles to start can lead to an inefficient cooling system and higher electricity bills. By choosing the right generator, you can avoid these issues and potentially save on your energy costs.

 

3. Potential damage

Using the wrong generator can unexpectedly overload, leading to a shorter lifespan for both the generator and appliances. This can result in expensive repairs and replacements over time. It's crucial to be aware of the potential damage that can occur from inadequate motor starting power, such as overheating in both generators and appliances, which can cause mechanical stress and overheating.

How do I determine the motor starting requirements for my home?

When preparing for a potential outage, we want to meticulously identify every appliance and device that will need to be powered. Beyond the obvious essentials like refrigerators, freezers, air conditioners, and heating systems, don't forget about other vital equipment such as lighting and communication devices. By making a comprehensive list of these items, you're taking a significant step towards ensuring your home's power needs are met during an outage, instilling a sense of security.

 

Check wattage

Note both the starting wattage and the running wattage of each appliance. This information, which can usually be found in the appliance's manual or on the label, is where the information is found to understand the power requirements of your home. The starting wattage, which is the power needed to start the appliance, can be significantly higher than the running wattage, which is the power needed to keep the appliance running. This difference is important to consider when calculating your overall power requirement.

 

Use a wattage calculator

The wattage calculator is a useful tool for determining how much power is required for a motor to start. To use it, you'll need to input the starting and running wattages of your appliances. There are many online tools available that can help you calculate your total power requirements for your appliances based on these wattages. You can also seek assistance from a professional who can guide you through this process.

 

Consulting a professional

For a more accurate assessment of your power requirements, it's advisable to contact your local Briggs & Stratton Dealer. These professionals can provide expert support in right-sizing your system, ensuring that you have the right amount of power to meet your needs during an outage.

68% greater motor starting capability than the competition

Briggs & Stratton PowerProtect 26kW home standby generator

The Briggs & StrattonⓇ PowerProtect™ 26kW Home Standby Generator boasts a 68% greater motor starting capability than the competition. Other factors that quickly help you narrow down your choices are features like NGMax, Eco-Cise™, and Dura-Zen™ corrosion protection. 

With the PowerProtect generator, you can be confident that you have enough power for your entire house. Briggs & Stratton home standby generators are designed with convenient hookups for both liquid propane and natural gas. For homes with access to natural gas, PowerProtect generators are an ideal generator. PowerProtect generators are engineered with NGMax™ technology for superior performance on natural gas, up to 13% more power than the competition. The reinforced, corrosion-resistant aluminum enclosures and bases with Dura-Zen™ coating provide long-lasting protection and an attractive appearance. Powered by the Vanguard® Commercial-Grade Engine, it guarantees reliable, continuous performance, reflecting the expertise of Briggs & Stratton. It features the best motor starting in the industry, ensuring smooth operation of large appliances during startup and offering more power than the competition.

 

The Briggs & Stratton comprehensive warranty on PowerProtect generators is designed to provide you with peace of mind. It covers labor, parts, and service, ensuring that you have no out-of-pocket costs for any potential issues. The Eco-Cise™ Weekly Test Mode, a convenient feature, ensures the generator operates optimally while reducing noise and fuel consumption. Suitable for off-grid use and demand response programs, it enables partnerships with utility companies for rewards. Learn more about the PowerProtect™ 26kW Home Standby Generator, here


Ready to start protecting your home?

Our Whole-House Generator Sizing Calculator allows you to select what you want to power in your home and directs you to the appropriate-sized generator system.

GET STARTED