MR introduces condition assessment for Circuit Breakers
MR expands the proven TESSA® FLEETSCAN 2D methodology to Circuit Breakers and in the future to entire Switching Bays
Maschinenfabrik Reinhausen (MR) is driving forward the digitalization of condition assessment in substations. In close cooperation with the University of Wuppertal, the proven methodology of TESSA® FLEETSCAN 2D - previously focused on power transformers - has been systematically extended to circuit breakers in air-insulated systems.
Holistic approach for grid operators
The aim is a comprehensive condition assessment of all key electrical assets in the substation -ranging from transformers and circuit breakers to entire AIS (air-insulated switchgear) and GIS (gas-insulated switchgear) systems.
The system is based on a two-dimensional evaluation model that describes both sustainability, via the lifetime consumption index, and the reliability of the asset, via the failure risk index. This enables grid operators to make well-founded OPEX-orientated maintenance decisions as well as CAPEX-relevant investment strategies.
The methodology integrates visual inspections, IR thermography, electrical measurements, and SF₆ gas analysis with strategic asset management criteria—providing a reliable basis for decision-making throughout the entire lifecycle.
Pilot project in Duisburg
Validating the 3-level approach under real conditions
Validating the 3-level approach under real conditions
The condition assessment of circuit breakers is based on a three-level approach as shown in the picture.
As part of a pilot project with Netze Duisburg GmbH, twelve 110-kV circuit breakers in air-insulated installations were assessed - mainly at Level 2. Due to the limited data base, the uncertainty of the condition assessments was relatively high. The 2D methodology accounts for this and marks evaluations with a corresponding data uncertainty range.
By carrying out additional measurements or extending the assessment to Level 3, the accuracy and reliability of the results can be significantly improved and the evaluation can be verified or refined. This results in a flexible, adaptive assessment system that adjusts to the available data and the specific situation of the asset.
Results of data collection and analysis
Results of data collection and analysis
The structured condition assessment provides a compact expert report that summarises the technical condition of circuit breakers in a clear and comprehensible manner. It highlights prioritised recommendations for action – from immediate measures to long-term strategies.
On this basis, investments can be planned in a targeted way, risks minimised and the operational reliability of systems increased in the long term.
The result: maximum transparency and a well-founded basis for effective asset management decisions.
International industry dialogue
The results were presented in a technical paper at CIRED 2025 in Geneva. Additionally, an online workshop with grid operators and interested parties from the DACH region was held in July 2025 to present the findings, discuss the methodology, and gather further requirements from practice.
Another contribution at international level is planned with a publication at CIGRÉ 2026 in Paris.
Future Outlook: Focus on assessments of entire switchgear
Currently, the assessment methodology is being expanded to include further equipment (e.g. current and voltage transformers as well as disconnectors), enabling systematic evaluations of entire switching bays in the future. The system is designed to cover both AIS and GIS switchgear. Combined with the existing transformer assessment, MR thus covers the most important electrical assets in substations and lays the foundation for continuous, data-based condition assessment of all critical assets in the substation.
