Generator Sizing Guide for Commercial Buildings

Jump To Sections:

• Why Generator Size Matters
• How to Calculate Your Power Requirements
• How to Size a Generator for a Commercial Space
• Why Choose a Cat^® Generator?
• Turn to Blanchard Energy for Your Generator Needs

When preparing your business for potential power outages, investing in a backup generator is one of the best things you can do to combat downtime and maintain safety. However, you may have some questions, such as how to size a generator for a commercial building or which brand is best for your applications. Get the answers below with our commercial generator sizing guide.

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WHY GENERATOR SIZE MATTERS

Having the right size commercial backup generator for your business is important. Many critical systems, such as fire alarms and emergency lighting, rely on backup power sources and help to maintain safety during an emergency or outage. You must also ensure your generator is the right size to comply with the National Electric Code (NEC) and National Fire Protection Association regulations.

Choosing a generator for your business that’s too small can lead to the following complications:

• Failures: If your backup power source isn’t suited for the size of your commercial space, the generator could fail to keep critical systems running.
• Unreliable power sources: Without an adequate generator, your business could end up with insufficient power.
• Generator damage: An undersized backup generator can lead to overheating and damage to the equipment.

On the other hand, using a commercial generator that’s too large for your business’s space can also cause issues:

• Electrical system damage: Using an oversized generator can put too much stress on your business’s electrical wiring.
• Inefficient power supply: If you use a bigger generator than your space requires, it may provide unreliable or insufficient power.
• Needless operational expenses: A backup power source that’s too large may lead to unnecessary utility expenses.

HOW TO CALCULATE YOUR POWER REQUIREMENTS

Explore the different ways to determine your commercial space’s unique power requirements:

Real-Time Measurement

The first method for calculating your power needs involves using a clamp-on ammeter on both legs of your electrical service.

Add the measurements together. This will give you the total amps your facility uses. Then, divide your total amps by three to find the three-phase current. Divide the amps by two to find the single-phase current.

Multiply your results by the supply voltage and then by 1,000 for the required kilowatts. Find the full load kilowatts by adding the power in kilowatts used by each emergency safety system according to the following articles of the NEC:

• 700
• 701
• 702
• 709

Historical Full Load Capacity

You can also find your power requirements by reviewing your past utility bills. Pinpoint the highest demand from the year prior. Use this number and add 25% to account for reserve capacity. This number will indicate your facility’s energy needs.

Square Footage Measurement

You can calculate your power requirements using your space’s square footage. The type of business you have will determine what equation you will use.

Retail stores will need to configure 10 watts per square foot and add 50 kilowatts to find their power needs. Other commercial applications will need to configure 5 watts per square foot and add 50 kilowatts to land on their requirements.

Sizing Calculator

You can also streamline the process by utilizing an online commercial generator sizing calculator. Consider using more than one just to make sure you’re getting accurate results.

Ultimately, your business will benefit from turning to a professional to determine the most accurate power needs for your space.

HOW TO SIZE A GENERATOR FOR A COMMERCIAL SPACE

Once you discover your power requirements, you’ll need to determine the size of generator you need. You can find the right generator for your business by exploring the performance charts that manufacturers provide with each model. Look over the different power ratings until you discover one that’s compatible with your space’s unique needs.

You can always turn to a professional for assistance in finding the perfect one for your requirements. They may be able to help you sort through the most important considerations to ensure you make the right buying decision.

The following are some of the key considerations for commercial generator sizing:

• Operation: You’ll likely want to invest in a generator that operates automatically and will power up on its own when there’s an outage.
• Power phase: Determine whether you need single-phase or three-phase power. Most businesses will require three-phase service.
• Noise rating: If your backup generator will interfere with business operations because of its sound, ensure you consider noise rating when choosing a model.
• Fuel source: Your company should also decide what type of fuel to utilize with the generator. The fuel you choose may impact your maintenance needs.

WHY CHOOSE A CAT^® GENERATOR?

When it’s time to decide on a backup generator, your business will benefit from choosing a brand known for its dependability. Caterpillar manufactures equipment you can rely on. When using a Cat^® generator, you can enjoy the following advantages:

• Durable manufacturing: Cat equipment is constructed of durable, long-lasting materials that will serve your business for years to come.
• A century of experience: Caterpillar was founded more than 100 years ago. Through continuous innovation and learning, the brand creates powerful generators that are reliable and well-built.
• Quality replacement parts: When you invest in a Cat generator, you can enjoy the convenience of ordering replacement parts from the same manufacturer, so you know they’re perfectly compatible with your equipment.
• Steady market value: Another benefit of opting for a commercial generator from Caterpillar is the equipment’s steady market value. Compared to other brands, Cat machinery can maintain its value better.
• Options: Caterpillar offers various types of generators. Your business can choose from many options to find the best model for your applications.

You can trust your Cat generator will keep your business’s lights on and operations running during a power outage.

TURN TO BLANCHARD ENERGY FOR YOUR GENERATOR NEEDS

If you’re looking for a generator for your business, turn to the experts at Blanchard Energy. Along with these tips to size a generator, our sales representatives and technicians are here to ensure your equipment is reliable and operating effectively when it matters most.

Blanchard Energy can help with all your commercial generator needs, including maintenance and sales. Contact us online or give us a call at 844.252.6242 to learn more.