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How To Gain UPS-Generator Harmony: A Detailed Explanation

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With unreliable grid power supply being the norm of the day, most businesses and industries have equipped themselves with generators or UPS. Some of them are clever enough to invest in both to ensure a reliable chain of power 24/7.

The world stands divided over which power solution is better- the Uninterrupted Power Supply (UPS) or the generator. As one of the leading UPS manufacturers, we at Nantech, Chennai, suggest combining the best of both worlds. UPS and generators are both essential parts of any power infrastructure. When integrated, they provide you with a seamless, highly-effective, and safe power solution for your business.

In this blog, we've explained everything you need to do to gain the combined power of your UPS and generator. But here's a small intro about both power sources before we venture into the details.

The Role Of UPS & Generator In Keeping Power Alive


Popularly called the UPS, the Uninterruptible Power Supply is an electrical apparatus that provides backup power when the main power supply is compromised. From powering a small household to running your entire computer system, the UPS is the top choice for many people.

The device contains batteries that automatically detect any loss of power and kick in to fill the gap within seconds or minutes. This results in assured continuity and functionality of your electric devices. Additionally, the UPS also safeguards your devices from unexpected power surges.

The generator

The backup generator can come in sizes as small as a suitcase or as large as a house. This self-powered device can generate electricity by converting mechanical power into electrical power. As per their capacity, generators can provide power for a longer period and effortlessly run heavy appliances.

Despite their differences in design and function, UPSs and generators are the most reliable solutions for uninterrupted power supply. Technology has simplified the way businesses operate and ease our reliance on electricity. Hence, it is easy to understand the outcome if these devices are used as a combination rather than stand-alone solutions.

If you plan to invest in both the UPS and generator, you need to know what to do to optimise these solutions and gain the most from them. Here are our guidelines.

Best Practices To Optimise Your UPS-Generator Combination

The concept behind the UPS-generator combo is to use the UPS running as long as possible and then switch to the generator power. The generator will supply the power until the main supply is restored or until the system is properly shut down. Generators and UPS can work in perfect harmony as long as you implement these best practices.

1. Evaluate the generator frequency

Always assess your generator frequency when using the UPS-generator combo. Here's why:

If the UPS' input voltage and frequency exceed the set level, the UPS will slip into the battery mode. When connected to the generator, the UPS may consider a generator an unstable power source if its frequency range is too wide. As a result, the UPS will run permanently on the battery, resulting in the battery failing and dropping your load.

2. Assess the generator's capacity

List the electrical devices you want your generator to power. This list includes the AC, lighting, computer systems, and other vital services. Now, assess if your generator can power these devices. If your generator isn't large enough, it will not be able to hold voltage and frequency within input tolerances.

Therefore, if you aim for potential growth with a generator-friendly UPS, it is wise to size up your generator whenever your budget allows it.

3. Consider your fuel options

There are three fuel options to get your generator up and running:

  • Propane
  • Diesel
  • Natural gas

Assess their pros and cons and choose the option that works best. For example, natural gas may slow down your generator and not deliver the desired outcome. Besides, you may have to invest in a larger generator in due course of time. On the other hand, propane is a better choice. However, it is diesel that takes the cake. It is the most preferred solution for generators with 50kW or more. On the downside, diesel costs are skyrocketing, and the fuel also has a short storage life.

4. Prevent overheating issues

Generally, there is an increase in temperature by 10 degrees Celsius when the generator operates. If the ambient temperature is around 40 degrees Celsius, the additional heat will damage your generator. You need to provision and scale your generator for more power to prevent this. You can:

  • Upsize the generator between 1.25 and 2 times the UPS output
  • Increase this up sizing amount if the generator supports extra electrical equipment

5. Provide strong grounding

People often overlook the need for strong electrical grounding, which could be a serious mistake when the UPS and generators are concerned. Electrical currents normally use the UPS to dissipate to the ground. Without proper grounding, they will bypass the UPS and use your cables and other devices to get to the ground. This sudden surge of electricity can cause equipment damage, shock hazards, and data loss.

To prevent this, you should:

  • Provide proper grounding
  • Adhere to grounding codes
  • Get experienced guidance

6. Choose double-conversion UPS

There's a good reason why we offer this suggestion:

In standby and line-interactive UPSs, battery power prevents frequency variations from affecting the protected load. In contrast, a double-conversion, online UPS recreates the sine wave and filters frequency variations during normal operation. Therefore your battery life remains as good as gold.

Moreover, the online UPS corrects voltage and frequency deviations since it constantly rectifies AC to DC and then inverts it back to AC. Therefore, if you are looking for seamless generator integration, double-conversion UPS is the right choice.

Quick Tips For UPS-Generator Integration

Here are some more pointers to keep in mind to optimise your UPS-generator integration:

  • Identify the various levels of power protection
  • Choose electronic generator governors as opposed to mechanical governors
  • Consider these five criteria while investing in generators:
  1. UPS power
  2. Harmonics
  3. Operational temperature
  4. Synchronisation
  5. Future electrical loads

You can always rely on our experts at Nantech to provide technical advice and consultation with UPS-generator integration. Please feel free to reach out to us for the right guidance.

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Author: Nantech Team
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