Many people believe smaller generators can be used for standby electric power because they are not running all the time. This is not only a myth but can actually be very detrimental. Unfortunately, generator under sizing is one of the most common mistakes committed by buyers.  Not only does it involve the risks of damaging your new asset (the generator), but it can also damage other assets connected to it, create hazardous situations, and even limit overall productivity of the unit and/or the business relying on it.  If nothing else, the key thing to remember here is that more is always better than less.  

While there is no substitute for having a certified electrician perform an inspection and calculate everything for you, the guidelines below do offer some great starting points and should at least get you started in the right direction:

Know Your Requirements: Going to a dealer and buying the best or cheapest generator available without any other consideration is clearly not the best approach. It is always better to delve deep into your power generation requirements before making a choice. You can do this in the following ways:
 

• Make a list of the items that need to be powered by the generator
• Make a note of the starting and running wattage of the respective items
• Calculate the total power requirements in KVA or KW

How to Find the Starting and Running Wattage: Getting the right starting and running wattage of the devices you intend to power is crucial for calculating the accurate power requirements. Normally, you will find these in the identification plate or the owner’s manual in the buyer’s kit of each respective device, tool, appliance, or other electrical equipment.

Ampere – Watt Conversion:  You may often find power requirements of tools stated in amperes. In order to convert the power requirement of a tool from ampere to watts, follow these calculations.

• For resistive load: Wattage = amperes x volts
• For reactive load: Wattage = (amperes x volts) x load factor

Power Requirement Charting: It often happens that you lose the owner’s manual or for some reason can’t find the power requirement specification of the tools and/or other electrical devices you’re running. Here is a sample power consumption chart that demonstrates some of the typical wattages used for common appliances and tools.  The chart is simply provided as an example to demonstrate how starting and running wattages differ, and how each device has specific consumption needs.  If you have questions over any particular items you can contact the manufacturer, consult an electrician, or contact us for a free consultation.

Different ways of Calculating:  Depending upon the type and number of devices, and the way the generator is scheduled to be used, there are a few different ways of calculating power requirements:

• Single motor running 
• Multiple motors running simultaneously
• No electric motors

Advantages of choosing the right size generator: Now that you have an idea on how to choose the appropriate size of generator to suit your needs, here’s just a few of the benefits obtained by going through that process:

• No unexpected system failures
• No shutdowns due to capacity overload
• Increased longevity of the generator
• Guaranteed performance
• Smoother hassle-free maintenance
• Increased system life span
• Assured personal safety
• Much smaller chance of asset damage