Generator Sizing Guide: All You Need To Know



Typically, buying a new generator is a significant investment, whether it is for your home or business. Since it is a long term investment, you need to make your decision carefully based on various factors. It includes pointers like which brand is reliable, which fuel does it run on and last and the most significant, the size of the generator. It is important to understand your requirements and then make an informed choice. To know what to choose, you first need to know what you have! Let’s take a look at generators and their classifications to help you make the right choice. 

Classification Of Generators 
Generators are classified into two main categories, namely, residential and industrial. Homeowners generally prefer installing a stationary standby model or a small, portable option. You can find them in sizes ranging from 2kW-2000 watts up to around 50kW. These types can generate more than what is required to power small household equipment that does not require a high voltage power supply constantly.  You'll be best off with a top rated portable generator with lots of reviews to back it up. Since industries have higher power demands, industrial generators also come in varying sizes ranging from around 20kW to almost over 3MW. Large companies and businesses require more capacity, thereby industrial generators often have three-phase motors to supply high voltage power. Several establishments like shopping malls, hospitals, educational institutions, banks rely on larger-capacity generators to tide them during power outages and power interruptions. 

Consult A Certified Electrician 
In order to make the right decision, you need to consult with a certified electrician and allow them to inspect your premises. This will help to determine the maximum power load at your home or place of business. Unfortunately, many people make the mistake of not consulting and wind up investing in a generator that is not suitable for their requirements. Although you can easily determine the maximum power load that will arise, it is safer to have a professional to do the calculations based on their experience and knowledge.  

Power Requirements 
Experts recommend making a list of all the items that rely on backup power. You need to include your key equipment pieces as well as computers, lighting, and desktop appliances. You will need to note the running wattage and starting wattage of each of these items. You can usually find this information either in the owner’s manual or on the information plate attached to the electrical device. Once you have collected the information, you need to ensure they are all using the same units and then add them up. The sum result is the peak power consumption you can expect. If you find this process difficult to do it yourself, you can call a certified electrician to do it for you.  

Making The Final Decision 
Once you have calculated the peak power consumption, you need to pick out a generator that has a rating of 5% to 10% higher than that. This ensures that it covers any margin for errors and also allows for unaccounted extra loads. The diesel generator is a better choice, click here to understand why. Choosing a generator with a slightly higher rating prevents it from running on its maximum capacity for long durations. This ultimately saves it from getting worn out sooner rather than later.  

Benefits of Picking a generator with a slightly higher capacity 
Investing in a generator that has a slightly higher capacity than your calculated peak power consumption offers a lot of advantages. 

  • The generator does not shut down due to overloading. 
  • The fuel efficiency will be higher. 
  • The generator will last for a longer time and will not need too many repairs during its lifetime.  
  • It is safer for the maintenance personnel and operators.  
  • It offers you scope for expansion in the future.  

Split The Burden Or Not? 
If your power requirements are on the higher side, you might be wondering whether to invest in a large single generator or invest in two or smaller generators and split the burden. If you are at loggerheads over this, it is recommended to invest in two or smaller generators. Else, you can check with an electrical expert to guide you through.  

More Flexibility 
With multiple generators on hand, you don’t have to worry about power outages at all. It holds true for businesses as there is no need to halt your business operations. In case one of the generators has to be shut down for maintenance or repairs, you know you can rely on the other. If you were relying on a single generator, this would not be the case and will cause you to stop your operations until the generator is switched back on.  

Cost-Effective 
Although it depends on various factors, it is more economical to rely on parallel generators than a single one. This stands true especially in cases when you need generators that are larger than the usual mass-produced generators. By investing in two or more smaller generators you can save money that would have otherwise been spent on an expensive customized generator. 

More Practical 
If you are short on space, it is a good idea to rely on two or more parallel generators than trying to find the space to fit a large commercial generator into a small room. Commercial generators are often larger in size and often take up a lot of space.  

Extend The Lifespan 
By relying on parallel generators, you end up splitting the burden between the generators, thereby extending their lifespan. It also helps prevent overburdening the power backup system. In fact, it is ideal to stick to a load of up to 80% of the generator capacity to ensure a longer lifespan. While you may be tempted to skimp on the size of the generator, it is wiser to invest in a generator that offers a slightly higher capacity than your requirements. After all, nobody wants to deal with a worn-out generator before the end of its lifespan. Choose a generator that’s right for your situation to provide the required backup plan for your home or business.