Generator Cooling System Maintenance

Generators are important equipment that play a vital role in powering various machines and equipment. Like any other machine, generators require regular maintenance to ensure that they function at their best. One critical part of a generator is its cooling system. The cooling system is responsible for maintaining the optimal operating temperature to prevent overheating and potential damage. In this blog post, we will discuss the importance of generator cooling system maintenance and some of the best practices to keep it running efficiently.

Diesel Engine Cooling System
Diesel Engine Cooling System – Image Credit to


Significance of Generator Cooling System Maintenance

Firstly, it is essential to understand the significance of generator cooling system maintenance. Neglecting this essential component can lead to significant problems that can be costly to fix. Regular maintenance can help identify potential issues before they escalate into significant problems. Hence saving your time and money. The cooling system also helps to keep the generator operating efficiently, reducing the risk of breakdowns and malfunctions.


Best Practices for Generator Cooling System Maintenance
Regular Inspection

One of the best practices for maintaining the generator cooling system is regular inspections. These inspections can help identify potential issues and prevent costly repairs. A professional generator technician can inspect the cooling system for leaks, corrosion, and other signs of wear and tear. They can also check the coolant level and ensure that the system is functioning correctly.


Replace Coolant Regularly

Another essential component of the generator cooling system is the coolant. Coolant is crucial to the system, and it must be replaced regularly to ensure the system’s optimal performance. Coolant can break down over time, lose its effectiveness, and cause corrosion, which can lead to costly repairs. It is recommended to replace the coolant every two years or as per the manufacturer’s guidelines.


Check Hoses and Belts

Belts and hoses are also essential components of the generator cooling system, and they can wear out over time. Regular inspections can help identify signs of wear and tear, such as cracks or leaks, and ensure that they are replaced before they fail. Replacing worn-out belts and hoses can prevent potential breakdowns and costly repairs


Clean the Radiator

Moreover, the radiator is an important part of the generator cooling system that helps dissipate heat. Over time, the radiator can become clogged with dirt, dust, and debris, which can reduce its effectiveness. Regular cleaning of the radiator can help maintain optimal performance and prevent overheating.


Use Quality Parts

Finally, using high-quality parts can help ensure the optimal performance of the generator cooling system. Cheap or inferior parts can cause damage to the system and lead to costly repairs. Using quality parts may cost more upfront, but it can save you money in the long run by preventing breakdowns and reducing repair costs.



Regular conduct of the generator cooling system maintenance is crucial for ensuring the optimal performance of the generator and preventing costly repairs. Following these best practices can help ensure the reliability and longevity of your generator. And reducing downtime and improving productivity as well. If you are unsure about how to maintain your generator’s cooling system, consult a professional generator technician for assistance.

Lead Acid battery repair?

Lead-acid batteries are commonly used in automobiles, generators, backup power systems, and other applications. This is mainly due to their low cost and high energy density. However, over time, lead-acid batteries can lose their ability to hold a charge, which can be frustrating and costly to replace. Fortunately, with the help of a battery repair charger, you can restore the capacity of your lead-acid battery.


The battery repair chargers are widely available in the market and also called as desulfators. It works by breaking down the sulfate crystals that can form on the battery plates over time. The Sulfate buildup is a common cause of decreased battery capacity. It can be particularly problematic in lead-acid batteries if they have left sitting for long periods of time.

Intelligent Battery Repair charger
Intelligent Battery Repair charger
To repair a lead-acid battery using a battery repair charger, follow these steps:
  1. Check the battery’s voltage: Before you begin, use a multimeter to check the voltage of the battery. If the voltage of the battery is above 10 Volts, then you are lucky to get the battery back to its life again.
  2. Disconnect the battery: Make sure the battery is disconnected from any devices. And remove it from the vehicle or system it is powering.
  3. Connect the battery to the charger: Connect the battery to the repair charger according to the manufacturer’s instructions. The charger will start working to break down the sulfate crystals on the battery plates.
  4. Monitor the charger: Keep an eye on the charger while it is working. The charging process can take several hours or even days, depending on the severity of the sulfate buildup.
  5. Test the battery: Once the charging process is complete, disconnect the battery from the charger. Then test its voltage using a multimeter. A good and successfully recovered battery will show its voltage minimum of 12.6V.


If the battery is still does not hold a charge after repairing it with a battery repair charger, it may be time to replace it.


In conclusion, if you have a lead-acid battery that has lost its ability to hold a charge, don’t throw it away just yet. With the help of a battery repair charger, you may be able to restore it to its former capacity. Remember to follow the manufacturer’s instructions carefully and monitor the charging process closely. This is to ensure that you achieve the best possible results.

Denyo Generator AVR Model Chart

Denyo Generator AVR Models
Denyo AVR Models

Denyo AVR Models used on Denyo Generators

Following charts would help you to find out your Denyo Generator AVR model easily. There are some generator models which can use one or more AVR models, but it is always recommend to get the support of an expert technician before replacing part numbers. AVR models such as AN-5-203, NTA-5A-2T and NTA-5E-2T are the most common Denyo Generator AVR models found in Denyo generators.

Welding Generators
Generator Model AVR Model
DCW-480 AN-5W-203
DLW-400 AN-5W-203
TLG-18SPY AN-5-203
TLW-450 AN-5W-203


Single Phase Generators
Generator Model AVR Model
10ESX AN-5-201A
15SPX AN-5-201A
18ESX AN-5-201A


13 to 25 kVA Three Phase Generators
Generator Model AVR Model
13ESK AN-5-203
15ESK AN-5-203
25ESI AN-5-203
25ESK AN-5-203
25SPI AN-5-203
25SPK AN-5-203

Note: For Generator models not included here on 13 – 25 kVA range generators, typically comes with AN-5-203 AVR model.


35 to 45 kVA Generators
Generator Model AVR Model

Note: For Generator models not included here on 35 – 45 kVA range generators of DCA series, typically comes with NTA-5A-2T type of AVR.


60 to 90 kVA Generators
Generator Model AVR Model

Note: For Generator models not included here on 60 – 90 kVA range generators of DCA series, typically comes with NTA-5A-2T type of AVR.


125 to 150 kVA Generators
Generator Model AVR Model
125SPH NTA-5A-2T
125SPK3 NTA-5A-2T
150SPH NTA-5A-2T
150SPK NTA-5A-2T

Note: For Generator models not included here on 125 – 150 kVA range generators of DCA series, typically comes with NTA-5A-2T type of AVR.


180 to 800 kVA Generators
Generator Model AVR Model
180SPK2 NTA-5E-2T
220SPK3 NTA-5E-2T
300SPK3 NTA-5E-2T
400SPK2 NTA-5E-2T
500SPK NTA-5E-2T
500SPM NTA-5E-2T
600SPK NTA-5E-2T
800SPK NTA-5E-2T

Note: For Generator models not included here on 180 – 800 kVA range generators of DCA series, typically comes with NTA-5E-2T type of AVR.

Japanese Generator Brands

Japanese Generator Brands
Japanese Generator Brands

Categories of Japanese Generator Brands

The Japanese Generator brands can be easily categorized into two major groups by their operating fuel type, as follows.

  1. Diesel Generators (DGs)
  2. Petrol or Gasoline Generators (PGs)

The major Diesel Generator brands not much in to manufacturing gasoline generators and Gasoline generator brands not much in to the Diesel Generator market. This is a key observation identifiable at the broader view on the Japanese Generator manufacturing industry.

Other key identification observed is Gasoline generator brands own their own engine part while majority of the DG brands does not manufacture their own engine for their DGs except Yanmar and Mitsubishi. But main products of both Yanmar and Mitsubishi are Engine, not the DGs.

Diesel Generator (DG) Brands


Denyo leads the market in Diesel Generator segment with a significant lead in the world, with its Japanese competitors easily. The reason could be that, they only focused on the Generator Alternator and Assembling part rather than manufacturing their own engines. Denyo Generators mostly equipped with Japanese Engines like Hino, Isuzu, Yanmar, Mitsubishi, Kubota, Komatsu etc. The compactness and fuel efficiency along with robustness are the key advantages of Denyo.


Airman comes second in the Japanese generator brands though their focus is very much similar like Denyo. Generator alternator part is the main focus of Airman, while using Japanese engines as of Denyo. The electrical part including AVR which both uses three phase sensing, use same fundamentals, but the parts are not replaceable between two. The soundproof canopy is also look same but one can easily differentiate between two easily from air vents design, door locks and panel board etc.

Nippon Sharyo & Shindaiwa

Both these too follow the Denyo and Airman in terms of design, where they manufacture the alternator part and use readily available Japanese industrial engines and assemble. However electrical part including AVR is using their own version and can not be replaceable.

Yanmar – Mitsubishi – Komatzu – Kubota

All of these brands share common feature, where all are Engine manufacturers. They use their own engine to their generators but alternator part may not be from their own. Since they use dedicated engine models, sometimes spare parts for engines which are too old, might hard to find. Since Denyo, Airman, Nippon & Shindaiwa uses uses very common industrial engines, spare parts are typically available even for 30 year old machines, mainly due to reconditioned and second hand availability.

Gasoline Generator Brands

Honda Vs Yamaha

Honda leads the Japanese gasoline generator market although tight competition by Yamaha. Yamaha is now equally manufacture both Diesel and Gasoline generators for domestics and low end segments, though Honda is not much into the Diesel generator manufacturing. Small portable Invertor generators is more popular from both Honda & Yamaha and equally perform well in operational and maintenance aspect as well. Further, both are in similar price range and offers hard to select one over other for invertor type portable domestic generators.


Even though Hitachi manufacture gasoline domestic type small generators, their main focus is into large scale power plants such as Gas, Diesel, Biomass & Wind turbine MW scale generators more precisely called commercial power plants.