Diagnostics, Preventive Maintenance, and Monitoring of Electrical Equipment and Insulation Systems

To ensure reliable operation in the energy and industrial sectors, we offer our clients a comprehensive range of specialised diagnostic services, as well as preventive maintenance and monitoring. These services are designed to prevent faults in electrical equipment and insulation systems for high-voltage rotating machines (motors, generators) and non-rotating machines (transformers). Our expertise also extends to the diagnostics of electrical insulating fluids and gases.

Our diagnostic, preventive maintenance, and monitoring services encompass a wide range of tests, many of which are conducted in our own laboratory, accredited by the Czech Accreditation Institute (ČIA). These tests are routinely applied in preventive diagnostic checks and during various operational stages of electrical machines, such as commissioning, decommissioning, and refurbishment. We also specialise in testing equipment under extreme operational conditions, such as failures or emergency shutdowns, where we work to identify the causes of failures.

The E-01 ORGREZ laboratory holds a leading position in the market, both in the range of tests offered and in knowledge and experience. Additionally, we have developed many of the methodologies used in diagnostics and measurements.

Diagnostics of rotating machines (generators, motors):

Measurement of insulation resistance, capacitance, and dissipation factor, including the voltage dependence of insulation resistance
Applied voltage tests (AC, DC, 0.1 Hz)
Testing of inter-turn insulation of windings, detection of turn-to-turn short circuits in rotor windings, impulse testing using atmospheric surge
Partial discharge measurements (e.g. global method, ozone detection in cooling air, ultrasonic testing)
Machine inspection through thermal imaging and other specialised tests

Diagnostics of non-rotating machines – transformers (power and instrument transformers):

Electrical measurements

Measurement of insulation resistance, dissipation factor, and capacitance, including the C2/C50 ratio
Measurement of winding resistance and ratios
Determination of winding connection configuration
Measurement of magnetisation currents and short-circuit impedance
Monitoring of changes in winding geometry using frequency response analysis (FRA)
Polarisation spectrum analysis (RVM) and dielectric spectroscopy in the frequency domain (DFR)
Measurement of tap changer switching times
Operational diagnostics of bushings
Applied voltage tests (AC, DC, 0.1 Hz)
Thermal imaging inspections and other specialised tests

Diagnostics of non-rotating machines through testing of electrical insulating fluids

Analysis of gases dissolved in oil (DGA), including determination of the total gas content
Analysis of furanic compounds released by the degradation of solid paper insulation into the oil

Diagnostics of electrical insulating fluids

Measurement of the breakdown voltage of liquid insulants at mains frequency
Determination of the water content in insulating oil
Determination of the acid number of mineral insulating oils
Determination of the density of mineral insulating oils
Determination of the interfacial tension between oil and water
Determination of the temperature dependence of dissipation factor, relative permittivity, and internal resistivity under direct current voltage
Determination of sludge insoluble in n-heptane
Measurement of particle count and size in insulating fluids using a particle counter
Determination of thermal-oxidative stability (TOS) of mineral insulating oils
Laboratory regeneration of insulating fluids
Testing for the presence of corrosive sulphur (qualitative and quantitative, including testing for DBDS)
Testing for inhibitor content
Analysis of passivator content in mineral oils using HPLCDetermination of PCB (polychlorinated biphenyls) content in mineral oils using gas chromatography

Diagnostics of solid paper insulation

Measurement of the water content in solid insulation
Measurement of DP (average degree of polymerisation)

Diagnostics of other electrical equipment

Testing of valve-type lightning arresters and gapless surge arresters for HV and EHV surge arresters
Measurement of switching on and off times, dynamic resistance, and current path resistance in circuit breakers
Diagnostic noise measurements for rotating and non-rotating electrical machines
Diagnostics of SF6 electrical insulating gas