What are Different Types of Transformer Repair & Field Service

When Transformer Repair Services are Needed?

Transformers are always built strong and they can withstand all types of harsh weather and operating conditions quite effectively. However like all devices they also need maintenance to keep working efficiently. 

When it comes to when transformer repair services are needed, then there are two different scenarios. One is the scheduled maintenance of the transformer where your electricity utility company does regular transformer repair work. 

Second is the on-call transformer repair service where your utility companies do repair work due to a certain damage that had happened to the transformer. 

Common Transformer Issues Requiring Repairs

The transformer repair & field services are always done to keep common issues from happening or when any one or more of these appear in the transformer. So it is important for you to understand all the common issues that can appear during the useful life of transformers.

Oil leakage

In oil type transformers, oil leakage or its contamination is the most common you will face during the entire useful life of the transformer. Transformer oil is used to keep the core and winding assembly insulated to avoid short circuit and also isolated from the outer environment. 

Oil leakage can happen due to a number of reasons and the most common of them is physical damage to the transformer tank. As transformers most of the time are installed in open atmosphere, any type of harsh weather like wind or thunderstorm or extreme heat can do physical damage to the tank. Other reasons for oil leakage include manufacturing defects in the tank or conservator.

As transformer oil is responsible for transformer core and winding insulation and isolation, any leaking of oil can result in insulation and isolation failure. So immediate transformer oil leak repair service is required to repair the damage and refill the transformer with oil.

Keep reading: Signs That You Need to Replace Your Oil-Filled Transformer

Overheating and insulation degradation

In dry type transformers, the core and winding assembly is insulated using epoxy resin. This resin makes a hard shell around the transformer winding to insulator and isolate the winding. To remove heat produced at the transformer winding either a natural convection or a force convection cooling system is used. 

If the cooling system fails to cool the winding section, it can cause overheating and as a result insulation degradation. Overheating and insulation degradation can also be caused by continuous high loading of the transformer. 

This can seriously affect the transformer performance and life, so an immediate transformer repair & field service is needed to fix the cooling system and insulation.

Get free: Transformer Insulation Failure

Core and winding failure

Core and winding failure is a major failure and can happen due to the above mentioned two common causes. It can also be caused by any manufacturing defect or by any external force that might physically damage the core and winding section. A transformer that is being subjected to extreme load for an extended period can also face core and winding failure.

This is a big and permanent failure and repairing transformers at site will not be possible. You have to take the transformer to a workshop that offers transformer maintenance service.

Electrical faults

There are also some small problems that can also lead to repairing transformers but mostly on site. Problems like blown fuse, broken wire, loose connection, and busing issues are minor issues that need transformer repair & field services to keep transformers working.

Mechanical Damage

There are other several parts like conservator tank, breather, and number of safety valves that help transformers work safer and better. Any mechanical damage to these parts and potentially make the transformer useless. So if any of these parts is damaged, it should be repaired immediately.

You may enjoy: How Long Does It Take To Repair A Transformer?

Different Transformer Repair Services

After understanding the common causes of the transformer repair, it is important for you to know what type of transformer service you need to call for your transformer.

Onsite Component Repair and Replacement 

You can call an onsite component replacement service or if you are a service provider, you can provide on site service, if you have to replace small transformer parts like transformer bushing, breather, or any other safety or control valve. 

You can also get or provide onsite field transformer service for repair or maintaining the cooling system of the transformer. When offering transformer maintenance services, it is important to use OEM certified parts only. 

Insulation Repairs and Rewinding Services

The transformer insulation repair and rewinding services is something that is not done on routine or scheduled maintenance. It is something done when a transformer is showing a clear sign of insulation damage like short circuit or significant decrease in efficiency.

The insulation on the transformer winding is subjected to very high temperature and as a result it starts to degrade over time. All transformers undergo major overhauling one of twice in their useful life where minor damages of the insulation are repaired.

In oil type transformers, the damage to insulation is always of such intensity that it needs transformer rewinding services to completely remove the damaged insulation and make entirely new transformer winding. Rewinding a transformer is only done when all other parts of the transformers are working perfectly and only winding is problematic due to insulation issues or short circuit in winding. 

In a dry type transformer, a cured resin shell covers winding and it degrades due to high temperature of winding. This shell if too much degrades can be repaired to achieve the proper insulation of the transformer winding.

Oil Reclamation and Replacement

In oil type transformers, the oil reclamation and replacement is the part of schedule maintenance because oil quality and quantity defines transformer insulation, isolation, and cooling efficiency. As some transformers need hundreds of liters of transformer oil, which does not come cheap, it became essential to do an oil reclamation service to cut the repair cost.

If your transformer is not working efficiently or showing signs of overheating, then bad or low low can be the problem. You cannot directly call the oil reclamation and replacement service as utility companies always have their own scheduled maintenance or general on call maintenance service. Usually utility companies decide on their own to do oil reclamation and replacement service after inspection.

Reading more: Guide to Transformer Maintenance

Types of Transformer Field Services

There are a number of services that are performed on the field where the transformer is installed. The field service can also include repair and replacement of parts on site but those parts need to be lightweight and small. 

Schedule Field Inspection Services

As all Transformers work continuously throughout their useful life and they are a pressure part of the electricity supply system. So to keep these Transformers running  your utility company I should do field service for all the Transformers installed in your area. 

Each field inspection service includes a thorough inspection of all the transformer parts like bushing, connections, tank oil level, temperature, and cooling system performance. All different types of transformer field services and Transformer repair activity can be done after the field inspection service.

You can also call your  electricity utility company if you are facing a problem with your transformer. Utility company will immediately send the inspection team to do all the required inspections and  on field testing  of the transformer.

Diagnostic Testing Service

When your utility company sends a team for transformer inspection either on schedule maintenance or on your call. Then the team performs a series of Diagnostic testing on the transformer and all of its parts. 

Three most common diagnostic test perform on transformers are

• DGA (Dissolved Gas Analysis)
• Insulation resistance and polarization index tests
• SFRA (Sweep Frequency Response Analysis)

Dissolved gas analysis is done to check the quality of transformer oil during the field services. This test is done to check the different types of gases dissolved inside the transformer oil. There are a number of gases that can be produced and dissolve in the Transformer oil due to some certain defects or faults like overheating, parking and partial discharge.

 To inspect the Transformer oil a small sample of the oil is collected from the Transformer and its analysis using gas chromatography. Quantity of different gases such as hydrogen ethylene Methane carbon monoxide and acetylene are measured. A high hydrogen level indicates partial discharge, similarly the high ethylene and Ethane level suggest overheating and acetylene in oil is caused by arcing happening in the Transformer winding. Running on the results either Transformer oil reclaiming or replacements repair service will be provided by the utility company.

Insulation resistance and polarization in that test is done to check the condition of the insulation of Transformer winding, oil, and core. Similarly this week frequency response analysis is done to check the defects caused by the mechanical deformation in the Transformer winding and core section. Due to the very high voltage and rent at the Transformer winding and core a small short circuit can produce a shock that in return can produce a mechanical defect in the Transformer winding or core.

Emergency Field Services

Utility companies provide emergency field services that are usually in response to either a natural calamity or human mistake. You can call the emergency Field Service if your Transformer fuse has a loan or the entire Transformer has been damaged due to any natural climate left on the Storm or even if it has happened due to human mistake.

Your electricity utility company will provide the emergency Field Service in the form of a blown fuse replacement or by a mobile transformer that will initially bypass the damaged Transformer and tell the utility company to install a new Transformer.

Retrofits and Upgrades

Utility companies also provide field services related to the retrofits and upgrades of Transformers. As technology is changing the field of transformer design, the new transformers available nowadays have much more sensors and electronic components to improve their working efficiency. 

So you can either call your electricity utility company to provide the retrofit and upgrade feel service or the company by their own will perform the retrofit and upgrade service of the Transformers. They will upgrade the Transformer components for better efficiency or they simply have to do this to comply with new rules and regulations issued by the concerned state.

Relocation Services

The utility company also has to provide the field services of relocation and  installation services to their customers.  There can be many reasons for this relocation service. You can ask for the relocation service if you are shifting your interest somewhere else and need the exact same Transformer to be shifted at the new site. 

You can also call for a location service if you happen to have all Transformer and you want to install the same or transfer and your new location. This relocation service can also be provided in the case that the client no longer needs the installed transformer. In such cases the utility company either uninstall and relocate the Transformer in the where house or simply  relocate it on a new site where there is a need for a very similar transformer.

Keep reading: Step-by-Step Guideline On Installing A Transformer

Factors to Consider When Choosing a Service Provider

If you have an industrial setup or residential place where you have installed several electrical Transformers and now you are looking to sign a contract with a service providing company for transfer more repair and field services. Then you should consider some factors before choosing the right Transformer repair and field services

• The service provider you slap should have the required certificate and stop should have the required expert in the Transformer repair and field services.
• The service provider you select should have all the advanced Diagnostic tools needed for the quality repair inspection and field services.
• As the Transformer installed in specific Industries needs specific type of inspection repair and services. So the service provider You slap should be properly trained and all its top should be the expert of your related field.
• As failure of Transformer means the entire industrial setup Reliance on that Transformer 4 electricity will not be operating until the Transformer has been fixed or replaced. So the service provider you slap should have the response time of minutes and should be able to replace or fix the entire blown transformer within the horse.

Conclusion

Electrical transformers work 24/7 during their entire useful life  and their continuous working is the only thing that keeps the electricity running through our homes and industrial setup. To give these electrical machines running a regular and quality Transformer repair and feel services or needed. Depending on the problem and damage, the electrical utility company can provide a number of different Transformer repair and field services to solve the problem. While selecting a service providing company for your electrical Transformers.  you should consider certificate use of advance tools and response time getting any factory Transformer repair and field services

Follow Up

Electrical transformers are such a crucial part of our electricity supply and distribution setup that their failure will prove catastrophic for our industrial or residential setup. To keep the electrical devices running regular transformer inspection repair and field services are needed.

We at Daelim Transformer offer quality transformers of all types, sizes, and power ratings. We also provide extended inspection, transformer repair and field services for transformers we have installed for our valued Clients. 

If you have any questions about our transformer repair and field services, Contact Us and we will talk you through the process.