Top 9 Maintenance Practices for Extending Distribution Transformer Lifespan

Not hesitant to say that the transformer is the heart of any electrical system. So, proper is utmost important. You know these components are sensitive, and if not appropriately monitored, could face failures at the most inappropriate times.

This blog highlights the simplest 10 maintenance practices that, if applied, can keep your transformer in shape for years. With these simple and basic steps, you can save your time, save costs, and most importantly, avoid breakdowns. So, keep learning!

1) Regular Visual Inspection

Distribution Transformer maintenance requires a regular visual inspection, which is a critical step to take as this will help prevent the larger issues. Small challenges become large issues. Here’s how to do it properly:

i) Look for oil leaks: You should check the transformer area for any signs of oil leaks because the oil leaking could cause overheating and insulation failure.

ii) Inspect physical condition: Also, check the outer structure of the transformer routinely, otherwise, you will incur a loss. Damage to casing, cracks, and rust are the factors that weaken the system.

iii) Check bushings: Bushings are components where the wires attach to the Transformer. Inspect them for dirt, burn marks, cracks, and tracking. You know, an increase in dirt tracking could cause harm to the short circuit.

iv) Recording colour changes: Record the colour change near junctions which indicate tampering, overheating, or electrical problems.  

v) Monitor noise levels: Transformers usually produce a humming sound, but if you hear an unusual sound like buzzing or clicking, it means there is an issue in the internal system of the transformer.

vi) Examining fans and other components: Radiators, as well as their associated cooling fans, should be clean. Check for working radiators as well. If these parts show blockages or a broken cooling system, it may lead to overheating.  

vii) Verify grounding connections: Check for damage within the grounding wires themselves. Well, secure grounding is critical for system reliability.  

viii) Look for rust peepholes: Rust on parts of metal can result in the weakening of the parts, leading to possible overpower failures.  

 2) Oil Testing and Analysis

Testing the oil regularly helps in problem diagnosis during the early stages. Now, let’s discuss the oil testing and analysis:

a) Check moisture content: Water content in the transformer oil will be problematic in the long run, and  Moisture also facilitates rust and internal damage. That’s why ensuring that the oil is dry and safe should always be confirmed through testing.

b) Test dielectric resistance: The oil’s capacity to resist electrical breakdown must be tested. This is best achieved through a dielectric strength test.

c) Monitor the dissolved gases: If gases are formed in the internal structure, it means there is a problem in the system.

d) Acidity inspection: It is important to check regularly the acidity level of oil because a high level of acidity in oil damages the insulation and metal parts..

e) Monitor colour and appearance: Clear oil in the transformer is an indication of well well-transformer. But, if it seems to be dark, cloudy or has floating particles, then you need to replace this oil.

3) Thermographic Scanning

It is safe to say that thermographic scanning is one of the best ways to find issues with a transformer. Some problems occurring in the transformer are not visible to the naked eye, which is why infrared cameras are used to detect heat patterns through the use of primary technology. This is how it helps:

• Detect Hot Spots

Hot spots are the areas that become hotter than they should be, which indicates loose connections, overloads, and even failing parts. So, these hot spots should be detected by thermographic scanning.

• Identify Cooling Issues

If the cooling parts of the transformer are not working well, then these issues be detected easily through thermographic scanning.

Through the thermographic scanning, we save our transformer from unexpected shutdowns. Moreover, transformers work efficiently and properly.

4) Checking and Tightening Electrical Connections

A transformer that operates safely and efficiently needs strong electrical connections. Problems caused by loose connections can worsen if not fixed in time. This is what you need to:

• Check all connection points: Look for signs of looseness and wear at terminals, bolts, and joints. A loose connection can subject a transformer to overheating and damage.

• Look for signs of arcing: Strange smells, burn marks, or melted insulation could point to arcing. This is a weak connection with high risks of fire.  

• Use proper tools:  Make use of correct torque tools to tighten connections. The parts of the transformer break with the over-tightening, but they remain loose with the under-tightening.

• Check during shutdowns:  It is better to inspect and tighten connections when the transformer is off. This eliminates the risk of an electrical hazard.  

• Replace damaged connectors:   All damaged parts like lugs, bolts or cables should be changed immediately, otherwise it becomes risky.

• Clean contacts properly:  Connections can be made weaker by dust, soil or oxidation. So, cleaning all contact surfaces helps in better bonding among the transformer parts.

• Inspect insulation connection:  Check all insulation on connecting parts to ensure it is fully safe because damaged insulation can cause a short circuit.  

5) Cleaning and Removing Dust or Debris

Proper maintenance of the external parts of the transformer unit is crucial for operational reliability and safety. Therefore, it is advised to implement the following best practices:

• Conduct periodic inspections: It is highly recommended to observe whether the external components of the transformer are clean from dust, leaves, or any other associated residues.

• Clean cooling fans and radiators: The external parts of the transformer serve a very specific purpose. They need to be cleaned in order to allow proper airflow. If air is not allowed to properly flow, the transformer can face overheating due to a lack of adequate ventilation.

• Wipe External Surfaces: It is sufficient to use a dry cloth. However, using damp cloths to wipe surfaces may result in undesired results; hence, the need to use a very small amount of water.

• Check ventilation openings: Make sure all vents and air passages are not blocked. Good and unobstructed airflows are critical to the efficient and optimised working of the system cooling.

• Employ appropriate techniques: Cleaning Brushes, cloths, and low-pressure air blowers are most appropriate for cleaning. Sharp or metal cleaning tools should be avoided.  

• Be gentle: Handle cleaning procedures with care. Many delicate parts may undergo damage if treated roughly, therefore, precautions must always be followed during cleaning procedures.  

6) Monitoring Load and Preventing Overload

Load monitoring and Overload prevention greatly enhance the lifespan and overall efficiency of the transformer. Preventing overheating and damage caused by overloading is really worth pondering. The following techniques can ensure optimised performance and longevity:  

Consistently checking the load on the transformer ensures it does not exceed rated capacity. This also helps track overload situations. Moreover, the use of load monitoring tools improves real-time tracking and monitoring. These devices alert the user once the transformer exceeds the safe limit.  

Apart from this, it is vital to have practical knowledge of rated loads and their limits in order to monitor overloading situations effectively. Each transformer is configured with a unique loading capacity. Overheating can be a direct result of transformer overload, and such transformers must be regularly checked for temperature.  

Additionally, pulsating peak loads must also be considered in the transformer design to avoid possible permanent damage. Well, circuit breakers and fuses should be used to provide safe overload disconnection; these protect controllers must be added to the transformer.  

7) Inspecting and Maintaining Breathers

Excellent breathers are important to oil maintenance in transformers, since they aid in the entry of air without allowing moisture or dirt to get into the transformer oil. Proper maintenance is crucial for the smooth running of the transformer. Here are the steps of inspection and maintenance:

• Inspect the breather on a regular basis:

Note down the condition of the breather every few months, looking for visible damage or blockage that may restrict movement or otherwise interfere with its function.  

• Ensure it’s clean and dry  

The breather needs to be free from oil, moisture and dirt. It has to be cleaned periodically to remove contamination which affects the quality of the transformer oil.  

• Silica gel inspection:  

Breathers make use of silica gel in the removal of moisture. See whether the silica gel has served its purpose or not. If it becomes changed or it becomes moisture saturated, then it needs to be replaced with the breathers.

• Examine for leaks and cracks:  

Check the breather for leaks or cracks. If a transformer is damaged, it exposes the apparatus to dirt or moisture, which needs to be eliminated.  

• Check for rust or corrosion

The non-removable sections of the breather appliance are prone to corroding or rusting due to moisture. Replace the parts if such a situation is noticed to contain damage.

• Make certain it is securely fitted:  

Ensure that there is no leakage of air through the breather. Any loose fittings can lead to contamination or insufficient ventilation.  

8) Bushing Inspection and Replacement

Transformer bushings carefully allow passage for the electrical conductors through the grounded tank of a transformer, while providing an insulating barrier that ensures no short circuits are formed. Here’s what you need to do with the transformer bushings:  

a) Inspect for Physical Damage: Well, check the bushings for any damage or frays. Even small damage can cause major problems like faults and oil leakage.  

b) Check for Oil Leakages: Look around the bushings in the transformer for any oil stains or signs of leakage. Leakage may suggest that the bushing seal is misplaced and needs to be checked urgently.  

c) Check the Porcelain or Composite Material: Look out for discolouration or erosion, as these are indicators of ageing. The insulating material may become ineffective over time, so it is slowly affecting the bushing’s range.  

d) Examine the Bushings' Gaskets: Gaskets prevent or allow the flow of oil. If the gasket is cracked or worn out, the bushing needs to be replaced to maintain seal stability.  

e) Inspect for Corrosion: Losing strength due to bushing weakening is not ideal. Make sure that there’s no rust or corrosion, especially on the metal parts.

f) Clean the bushing:  Take care not to use any harsh materials while cleaning the bushing with a cloth or a soft brush. These materials would scratch the surface, which becomes a worse problem.

g) Check the bushing’s connection points: Check the connections of the bushing. Clean and properly fitted connections free of rust safeguard against overheating and faults.  

i) Replace damaged bushings immediately:  If the bushing in the transformer has signs of damage or any other failures, replace it immediately, as if it is not replaced, the bushing can cause larger electrical issues.  

9) Grounding System Check

The proper operation of a transformer depends on having a grounding system. Without it, the system would not be able to protect itself. Here is how you can maintain and check grounding systems:

• Inspect grounding connections regularly: Check the grounding connections. If there is any damage, rust or loosening of components, it results in a bigger problem.

• Ensure a strong, continuous ground path: Examine if the ground wire is tightly enclosed. A path without breaks is important for the safety and proper operation of the transformer.

• Check ground rods and electrodes: Examine if the ground rods or electrodes are free and intact of any mechanical damage and corrosion. Well, these parts give the main path to the faults, which are safely discharged into the earth.

• Ensure effective grounding of all components: Check that all parts of the transformer, including metallic parts, bushings, and tanks, are effectively grounded. This avoids electrical shock dangers.  

10) FAQS

1. How often should I test transformer oil?

It is advisable to have transformer oil tested at a minimum of once a year. If the transformer is working in severe conditions, then it needs to be tested more frequently. Regular testing will assist in identifying contamination or moisture problems.

2. Can I do basic maintenance myself?

Of course. You can do basic maintenance like cleaning, checking and tightening, and monitoring oil levels. But the more advanced measures, like oil testing or internal inspections, should be monitored by experts for safety.

3. What’s the average lifespan of a well-maintained transformer?

If maintained appropriately, a transformer has a life expectancy of between 30 to 40 years. Routine maintenance, such as oil analysis and sight examination, improves performance and guarantees dependable operation over the entire service life.

11) Conclusion

It is vital to maintain your distribution transformer in good condition, and if you fail to maintain the distribution transformer, it will lead to a bigger problem. Well, these maintenance practices can help you prevent an unexpected failure.

When you are thinking of spending money on high-quality transformers, Delixi is always trustworthy. With our reliable products, a strong performance is guaranteed along with long-lasting value. Care for your equipment today because just a bit of care can go very far! Alright! You can contact Delixi by just clicking here.