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A transformer is not a maintenance-free device, and even if it appears to be operating without issues, it can be a source of significant operational complications. During operation, its components naturally age, particularly the electrical insulation system. This process is also associated with a gradual deterioration of technical parameters.
“These subtle processes reduce efficiency and reliability until one day they cause a sudden failure or a total breakdown of the transformer. And that can cost the operator days or months of operation, cause significant financial losses, endanger workers, or lead to a complete shutdown of operations,” warns Jan Krišpín, CEO of ORGREZ, a.s.
When maintenance is postponed and inspections and comprehensive diagnostics are neglected, the potential risk of unplanned outages increases, operational losses rise, and the service life of the equipment is shortened.
“Emergency repairs are always more costly than preventive maintenance and often result in a longer downtime before the equipment is brought back online. Moreover, the delivery time for a new transformer can take several years these days,” adds Jan Krišpín, drawing on his operational experience.
Energy losses as both an operational and economic obstacle
Throughout a transformer’s service life, energy losses occur that represent a constant burden for the operator—not only operationally but also economically. These losses directly impact electricity consumption and, consequently, overall costs. An inefficient transformer can cost the operator hundreds of thousands of crowns a year, without any noticeable reduction in efficiency.
In practice, it is still common for losses not to be systematically or closely monitored at the level of individual devices. Without regular measurement and evaluation, however, it is impossible to reliably determine their actual extent or development over time. Decisions regarding continued operation, maintenance, repair, or potential replacement of a transformer are thus often made without sufficient knowledge of the transformer’s actual technical condition. This approach can lead to inefficient use of the equipment—instead of immediate replacement, there is a tendency to keep the equipment in operation for as long as possible.
The Importance of Diagnostics and Regular Maintenance
The foundation of effective operation and a long service life for a transformer is therefore not only regular maintenance but also diagnostics. These activities make it possible to monitor the technical condition of the equipment, identify potential problems in a timely manner, and plan for repairs and future replacements.
“Diagnostics provide information on the current condition of the electrical insulation system, its parameters, and the transformer’s operating parameters. Based on this data, further steps can be planned, ranging from routine maintenance to repairs or modernization,” explains Jiří Gregor, Director of Business Development at ORGREZ.
Diagnostic measurements provide accurate data on actual losses and clear evidence as to whether the equipment should be retained or replaced. The measurements give operators a comprehensive set of technical, economic, and environmental indicators. These enable the identification of risks, reduce the likelihood of failure, extend the equipment’s service life, and optimize overall operating costs.
Efficient On-Site Measurement of Transformer Losses
ORGREZ has many years of experience in comprehensive transformer maintenance. This includes diagnostics, regular inspections and maintenance, repairs, refurbishment, and other specialized services, not only in the energy sector.
Part of the services offered is the EMTRA solution, a proprietary mobile device capable of measuring transformers effectively: performing measurements directly at the installation site, i.e., on-site, and, most importantly, with minimal disruption to operations. The solution can analyze losses and, in combination with other ORGREZ services, comprehensively assess the condition of the transformer.
As Jan Krišpín notes, the key lies in the combination of safety and the informative value of the results: measurements are performed via a gradual, controlled ramp-up of sinusoidal voltage, without voltage spikes and without generating higher harmonic frequencies.
The results are presented clearly to enable informed decisions regarding the continued operation of the equipment. If necessary, comparisons of alternative operational scenarios can be provided through LCA/LCC analysis, carbon footprint assessment, and economic evaluation.
The measurements themselves provide detailed and valuable information about the current technical condition of the equipment. For transformers, we primarily monitor parameters such as insulation resistance, dissipation factor (tg δ), capacitance in various configurations, transformation ratio and phase shift, as well as no-load and short-circuit voltages, and compare these values with the rated values.
“In cases where nameplate values or documentation are unavailable, we are able to perform a comprehensive measurement. The data obtained allows us to detect any deviations, insulation aging, or other hidden faults that may affect safe operation. Furthermore, the EMTRA device expands diagnostic capabilities beyond mere loss measurement. For example, it enables induced voltage testing, which is particularly beneficial after repairs performed directly at the installation site, or even in inspection towers where a specialized testing facility is not available. “This method, based on gradually (slowly) loading the transformer, contributes to a more thorough verification of its functionality and reliability under real operating conditions,” adds Jiří Gregor.
How can we summarize the topic of transformer maintenance? It is not an expense, but a rational investment in reliable and, above all, safe operation, longer service life, and cost-effective operation. Professional transformer maintenance often pays for itself in just a few months. The sooner you start, the more you can save, and the longer you will be able to rely on your equipment.
You can read more about our transformer maintenance services on the following page.