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Transformer services

Transforming service into reliability

Whether power transformers, reactors, transformers for industrial applications, phase-shifting transformers, or HVDC transformers – transformers are crucial for ensuring a trouble-free supply of power with no interruptions. As reliable, rugged key components, they are frequently in use for decades at a time – and are thus subject to the unavoidable effects of aging and wear.

Strategically increase value with TLM


How can you plan your expenditures in a targeted way and systematically control the timing of new investments? How can you avoid unforeseeable outages and minimize planned downtimes? And how can you reduce the impact on the environment while maximizing transformer availability? The answer to these questions is TLM™ – Transformer Lifecycle Management™ – the service concept from Siemens for all the transformers in your network, regardless of age, manufacturer, or power. We service all generations of transformers.


Our TLM service concept is designed to prevent unplanned downtimes and optimize planned maintenance measures. We’re aware that you have fewer and increasingly shorter windows of opportunity even for planned service interruptions. Our response is technologies and methods that are as mobile as our experts. From oil-drying systems to high-voltage testing stations, we provide mobile repair workshops to support you on-site. Mobile teams and technologies are elements that ideally complement the performance spectrum of Siemens’ repair facility – they’re fast, flexible, and can be integrated in your operations.

Highlight services for transformers

Transformers are the cornerstone of power generation, transmission, and distribution systems. Their outages or failures usually have far-reaching consequences on large parts of the power system.

We’ll get your transformers back in top form – and without service interruptions

The Siemens TLM™ method for extending service life minimizes the unavoidable, undetectable, and ongoing aging process that is taking place inside your transformers. Our stationary and continuous transformer drying system and moisture monitoring SITRAM® DRY as well as our mobile container-mounted solution SITRAM REG for the lasting regeneration of the transformer oil filling are internationally-recognized technologies, and round out our offerings for improving cooling efficiency sealing. These can easily be integrated as retrofit solutions. The regeneration of the oil filling in particular not only eliminates frequent oil changes, but also offers substantial economic and ecological advantages, as it is performed during normal operations.

Intelligent condition diagnostics for transformers

SITRAM DIAG helps prevent breakdowns while optimizing your transformers’ utilization and availability.

How is your fleet of transformers really doing? Siemens TLM diagnostics makes it possible to detect the current condition with high precision and therefore classify operational reliability for all makes and models and all voltage and power levels. Especially after extraordinary events such as thunderstorms and lightning, relocations, and similar occurrences, comprehensive testing including on-site high-voltage tests is recommended – and with TLM, this is possible with the high quality equivalent to testing in the factory. Mobile TLM high-voltage tests are also used for acceptance testing following on-site repairs.


Our modular diagnostics program for power transformers SITRAM DIAG consists of three levels of analysis and many additional stand-alone modules for the selection and examination of irregular transformers in ever greater detail. You can choose the level of diagnostics that best fits your needs: Essential Diagnostics is performed during your normal operations, while the Advanced Level requires minimum outages. The ultimate level integrates high-voltage testing to optimally evaluate the operational condition and residual life span of each of your power transformers, based on our decades of experiences and highly advanced diagnostic methods. 

Transforming knowledge into availability

Service overview

Services for your transformers throughout their entire lifecycle

Siemens TLM is based on the expertise available in all Siemens transformer factories, which are well-known for high quality and low failure rates. Our highly experienced transformer experts provide the most effective lifecycle solutions for power transformers of any age and any brand along the value chain from reactive to proactive services.