Preface
In a previous article, we overviewed the circuit breaker maintenance practices presently in application, including a listing of some of the important tests in use, with reference to the applicable international standards.
All these tests have to be coordinated and well planned since the collection of data is spread over a relatively long periods of time. In order to achieve these goals, we need to set up a maintenance program.
In the present article you will find a summarized description of a typical maintenance program’s structure (Fig 1) (see PDF) and its main components. We hope it will give maintenance planners managers enough insight to shape their breaker maintenance programs or to initiate one if it does not exist yet.
Introduction
Because of its protective role, the circuit breaker plays an important role in transmission and distribution networks. If it breaks down the impact on the network can be serious. In addition to the damaged equipment, the cost of current interruption can be tremendous, since current interruptions are subject to severe penalty clauses in Electrical energy supplying contracts. Not to mention compromising the substation personnel safety, as they would be at risk of injury.
The best practice to avoid breakdowns then, is to apply proper maintenance. Since the breaker is like a black box, the only way to assess its condition with certainty is to take it apart. This can be a costly business, especially if it is not necessary.
This leads to the necessity of applying a multitude of maintenance actions (inspections and tests), in order to collect enough information on the actual condition of the breaker, which in turn permits a decision to proceed with repairs in time.
Maintenance Actions
The maintenance of circuit breakers relies then, on the application of a number of actions, called maintenance actions. These actions can range from a simple reading, like an operation counter, to a full inspection including disassembly of a major part, as an interrupter chamber for example.
Maintenance actions on circuit breakers are numerous and diverse, but they all serve to keep a close eye on the breaker’s condition to correct it before breakdowns occur.
Some of these actions have to be repeated on a periodic basis. The information has to be recorded and analyzed to reach a verdict. Fig 2 (see PDF) . Inspections and periodicity table, shows a list of possible inspections classified according to four categories of inspections:
• Routine inspections
• Limited inspections
• Provisional inspections
• Complete inspections
Each family of circuit breakers needs to have its specific list of inspections and periodicities. All these actions need to be planned and coordinated. Setting up a program called “Maintenance Program” does all of this.
Maintenance Program
In essence a maintenance program serves to:
• Coordinate the maintenance actions on a timescale;
• Collect data on the actual condition of the breaker
• Organize the collected data for analysis;
• Analyze the collected data;
• Plan intervention if needed.
Maintenance Program’s Elements
In order to reach the above-mentioned objectives, the program has to rely on the following elements:
• Planning;
• Observation & Testing (Data collection);
• Analysis;
• Planning
• Intervention.
Observation:
This is the part that collects information from all sources. The information collected is organized in databases. Some of these databases are described as follows:
Breakers Database (Fig 3) (see PDF) : First of all we need to know our breakers. This is achieved by maintaining a database of installed equipment. This database should contain, in addition to other required information, the following:
• Type;
• Manufacturer;
• Serial number
• Technology (SF6, Air blast, Oil, etc.);
• Year of manufacture;
• Location;
• Electrical characteristics (Voltage, Amperage, Breaking capacity, making capacity, etc.);
• Application;
• Date of installation;
• Various information, proper to the breaker itself.
Tests database (Fig 4) (see PDF) : This database contains a list of required inspections and periodicities (prescribed time periods between successive maintenance actions to be repeated systematically) to be conducted on the breakers.
Collected data database (Fig 5) (see PDF) : This database organizes, for each breaker, the data collected in various inspections, and it may include:
• First test sheets results;
• Inspections results over time;
• Repair interventions;
• Operation Counter
• Pressure gauges readings
• Temperature readings
• Timing readings
• Insulation readings
• Travel Velocity readings
• Contact resistance readings
• Oil quality checks
• Moisture measurements
• SF6 by products measurements
• Contact condition inspection (following a complete inspection for example)
• Incidents;
• Etc.
This information serves primarily to conduct an analysis in order to determine the type and urgency of maintenance interventions. It also serves as historical data for future statistical and durability studies.
Inspection and Tests Planning:
This is the part that organizes and coordinates the inspection sequences so the maintenance people can prepare the required maintenance actions in advance (Purchasing department, Warehouse, maintenance teams, operators, etc.). to increase efficiency in collecting information. The following figure (Fig 6) (see PDF) gives an idea on a possible course of inspection planning.
Analysis
Teams of highly trained engineers and technicians process all the information gathered in the previous sections and stored into well-organized databases. These teams have the responsibility to reach a verdict based on the available information, and determine the required actions and priorities. This information is put into a specific database, Analysis database (Fig 7) (see PDF) that is used to prepare interventions.
This database has to contain:
• Breaker serial No, to identify the equipment being analyzed;
• Analysis report No, that details the findings and recommendations;
• Advisory No, if any;
• Priority level of each recommendation;
• Deadline date for the intervention;
• Analysis date;
• Analysts names;
• Various required information, etc.
Advisory:
Advisories are reports that inform the maintenance manager on what to do and on which equipment. It contains, at least:
• A list of concerned breakers;
• A list of actions to do;
• A description of the reasons (reference to Analysis report);
• A list of parts;
• A list of special tools;
• Drawings and instructions;
• Etc.
Intervention:
Once the advisory is initiated, interventions can now be planned.
For example the result of a complete inspection of an interrupter module may reveal a critical condition that may require an intervention program on all similar breakers.
This requires coordination between network administration and maintenance teams. A list of to-do actions, parts and special tools must be determined, not to mention training, quality assurance, budget cost control, etc.
Once the intervention is completed, keeping record of it is crucialmatter. Every corrective action or intervention on the circuit breaker has to be recorded for comparison and future analysis. A part’s repetitive failure for example may raise concerns on more critical problem or a design flaw. A breaker’s history has to be available for reliability studies; this may influence the future of a circuit breaker family (systematic replacement or refurbishment).
The Intervention database (Fig 8) (see PDF) keeps record of such information, it must contain:
• The breaker’s serial No;
• The action plan and schedule;
• Technical team assigned;
• Start date;
• Deadline end-date;
• Date of completion;
• Manager name;
• Etc.
Conclusion
As we mentioned from the beginning, the present article gives the basics of setting up a maintenance program. Detailed discussion is not relevant here, since we are dealing with a great deal of information. The following figure (Fig 9) (see PDF) recapitulates briefly as follows:
Information from the breaker’s database and Tests database lead to collect information in Data database. This data serves to conduct a thorough analysis, leading to maintenance interventions. Interventions meant to happen before any breakdown occurs.
And last but not least, as it is obvious that any relational database can do the job, we can find many programs on the market that are specifically designed for this purpose. It is the task of specialized personnel to determine the need versus the program's capability in order to reach the perfect choice.
Bibliography
The present article is based on our personal experience with Hydro-Québec's maintenance program model.
About the Authors
Dr. Fouad Brikci is the president of Zensol Automation Inc. He was the first to introduce the concept of truly-computerized test equipment in the field of circuit breaker analyzers. As a former university teacher in Ecole Polytechnique — Algiers and CNRS - LAAS researcher in France, Dr. Brikci has developed experience in the fields of electronics, automation, and computer science. Most activities were focused on the industrial application of computers. Among his achievements are the development of fully comput¬erized measuring systems for quality control in circuit breaker manufacturing, laboratories, and maintenance services of electric utilities. Dr. Brikci holds a PhD in Electronics and a Master in Sci¬ences in EEA (electronics, electrotechnics, and automation) from the University of Bordeaux, France.
http://www.zensol.com, email : zensol@zensol.com
Emile Nasrallah is an electrical engineer specialized in Power circuit breakers maintenance. Since graduation in 1984 he worked as a field engineer. In1990 he joined the worldwide circuit breaker manufacturer GEC ALSTHOM as a specialized field engineer. In 1997 he became the manager of MV & HV circuit breaker SF6 division of ALSTOM, responsible of technical support, maintenance and training for SF6 circuit breakers. In 2001 he became manager of Air blast circuit breaker division for AREVA. He was in charge of the Air blast (PK and PKV) refurbishing program in partnership with hydro-Quebec and introduced a unique administration system for the program (average of 35, 735 kV PK air blast circuit breaker per year). In 2005 he joined General Electric Company of Canada as a senior circuit breaker specialist and is in charge of the circuit breaker division of the Montreal service centre, responsible of the remanufacturing program for Oil circuit breakers
In a previous article, we overviewed the circuit breaker maintenance practices presently in application, including a listing of some of the important tests in use, with reference to the applicable international standards.
All these tests have to be coordinated and well planned since the collection of data is spread over a relatively long periods of time. In order to achieve these goals, we need to set up a maintenance program.
In the present article you will find a summarized description of a typical maintenance program’s structure (Fig 1) (see PDF) and its main components. We hope it will give maintenance planners managers enough insight to shape their breaker maintenance programs or to initiate one if it does not exist yet.
Introduction
Because of its protective role, the circuit breaker plays an important role in transmission and distribution networks. If it breaks down the impact on the network can be serious. In addition to the damaged equipment, the cost of current interruption can be tremendous, since current interruptions are subject to severe penalty clauses in Electrical energy supplying contracts. Not to mention compromising the substation personnel safety, as they would be at risk of injury.
The best practice to avoid breakdowns then, is to apply proper maintenance. Since the breaker is like a black box, the only way to assess its condition with certainty is to take it apart. This can be a costly business, especially if it is not necessary.
This leads to the necessity of applying a multitude of maintenance actions (inspections and tests), in order to collect enough information on the actual condition of the breaker, which in turn permits a decision to proceed with repairs in time.
Maintenance Actions
The maintenance of circuit breakers relies then, on the application of a number of actions, called maintenance actions. These actions can range from a simple reading, like an operation counter, to a full inspection including disassembly of a major part, as an interrupter chamber for example.
Maintenance actions on circuit breakers are numerous and diverse, but they all serve to keep a close eye on the breaker’s condition to correct it before breakdowns occur.
Some of these actions have to be repeated on a periodic basis. The information has to be recorded and analyzed to reach a verdict. Fig 2 (see PDF) . Inspections and periodicity table, shows a list of possible inspections classified according to four categories of inspections:
• Routine inspections
• Limited inspections
• Provisional inspections
• Complete inspections
Each family of circuit breakers needs to have its specific list of inspections and periodicities. All these actions need to be planned and coordinated. Setting up a program called “Maintenance Program” does all of this.
Maintenance Program
In essence a maintenance program serves to:
• Coordinate the maintenance actions on a timescale;
• Collect data on the actual condition of the breaker
• Organize the collected data for analysis;
• Analyze the collected data;
• Plan intervention if needed.
Maintenance Program’s Elements
In order to reach the above-mentioned objectives, the program has to rely on the following elements:
• Planning;
• Observation & Testing (Data collection);
• Analysis;
• Planning
• Intervention.
Observation:
This is the part that collects information from all sources. The information collected is organized in databases. Some of these databases are described as follows:
Breakers Database (Fig 3) (see PDF) : First of all we need to know our breakers. This is achieved by maintaining a database of installed equipment. This database should contain, in addition to other required information, the following:
• Type;
• Manufacturer;
• Serial number
• Technology (SF6, Air blast, Oil, etc.);
• Year of manufacture;
• Location;
• Electrical characteristics (Voltage, Amperage, Breaking capacity, making capacity, etc.);
• Application;
• Date of installation;
• Various information, proper to the breaker itself.
Tests database (Fig 4) (see PDF) : This database contains a list of required inspections and periodicities (prescribed time periods between successive maintenance actions to be repeated systematically) to be conducted on the breakers.
Collected data database (Fig 5) (see PDF) : This database organizes, for each breaker, the data collected in various inspections, and it may include:
• First test sheets results;
• Inspections results over time;
• Repair interventions;
• Operation Counter
• Pressure gauges readings
• Temperature readings
• Timing readings
• Insulation readings
• Travel Velocity readings
• Contact resistance readings
• Oil quality checks
• Moisture measurements
• SF6 by products measurements
• Contact condition inspection (following a complete inspection for example)
• Incidents;
• Etc.
This information serves primarily to conduct an analysis in order to determine the type and urgency of maintenance interventions. It also serves as historical data for future statistical and durability studies.
Inspection and Tests Planning:
This is the part that organizes and coordinates the inspection sequences so the maintenance people can prepare the required maintenance actions in advance (Purchasing department, Warehouse, maintenance teams, operators, etc.). to increase efficiency in collecting information. The following figure (Fig 6) (see PDF) gives an idea on a possible course of inspection planning.
Analysis
Teams of highly trained engineers and technicians process all the information gathered in the previous sections and stored into well-organized databases. These teams have the responsibility to reach a verdict based on the available information, and determine the required actions and priorities. This information is put into a specific database, Analysis database (Fig 7) (see PDF) that is used to prepare interventions.
This database has to contain:
• Breaker serial No, to identify the equipment being analyzed;
• Analysis report No, that details the findings and recommendations;
• Advisory No, if any;
• Priority level of each recommendation;
• Deadline date for the intervention;
• Analysis date;
• Analysts names;
• Various required information, etc.
Advisory:
Advisories are reports that inform the maintenance manager on what to do and on which equipment. It contains, at least:
• A list of concerned breakers;
• A list of actions to do;
• A description of the reasons (reference to Analysis report);
• A list of parts;
• A list of special tools;
• Drawings and instructions;
• Etc.
Intervention:
Once the advisory is initiated, interventions can now be planned.
For example the result of a complete inspection of an interrupter module may reveal a critical condition that may require an intervention program on all similar breakers.
This requires coordination between network administration and maintenance teams. A list of to-do actions, parts and special tools must be determined, not to mention training, quality assurance, budget cost control, etc.
Once the intervention is completed, keeping record of it is crucialmatter. Every corrective action or intervention on the circuit breaker has to be recorded for comparison and future analysis. A part’s repetitive failure for example may raise concerns on more critical problem or a design flaw. A breaker’s history has to be available for reliability studies; this may influence the future of a circuit breaker family (systematic replacement or refurbishment).
The Intervention database (Fig 8) (see PDF) keeps record of such information, it must contain:
• The breaker’s serial No;
• The action plan and schedule;
• Technical team assigned;
• Start date;
• Deadline end-date;
• Date of completion;
• Manager name;
• Etc.
Conclusion
As we mentioned from the beginning, the present article gives the basics of setting up a maintenance program. Detailed discussion is not relevant here, since we are dealing with a great deal of information. The following figure (Fig 9) (see PDF) recapitulates briefly as follows:
Information from the breaker’s database and Tests database lead to collect information in Data database. This data serves to conduct a thorough analysis, leading to maintenance interventions. Interventions meant to happen before any breakdown occurs.
And last but not least, as it is obvious that any relational database can do the job, we can find many programs on the market that are specifically designed for this purpose. It is the task of specialized personnel to determine the need versus the program's capability in order to reach the perfect choice.
Bibliography
The present article is based on our personal experience with Hydro-Québec's maintenance program model.
About the Authors
Dr. Fouad Brikci is the president of Zensol Automation Inc. He was the first to introduce the concept of truly-computerized test equipment in the field of circuit breaker analyzers. As a former university teacher in Ecole Polytechnique — Algiers and CNRS - LAAS researcher in France, Dr. Brikci has developed experience in the fields of electronics, automation, and computer science. Most activities were focused on the industrial application of computers. Among his achievements are the development of fully comput¬erized measuring systems for quality control in circuit breaker manufacturing, laboratories, and maintenance services of electric utilities. Dr. Brikci holds a PhD in Electronics and a Master in Sci¬ences in EEA (electronics, electrotechnics, and automation) from the University of Bordeaux, France.
http://www.zensol.com, email : zensol@zensol.com
Emile Nasrallah is an electrical engineer specialized in Power circuit breakers maintenance. Since graduation in 1984 he worked as a field engineer. In1990 he joined the worldwide circuit breaker manufacturer GEC ALSTHOM as a specialized field engineer. In 1997 he became the manager of MV & HV circuit breaker SF6 division of ALSTOM, responsible of technical support, maintenance and training for SF6 circuit breakers. In 2001 he became manager of Air blast circuit breaker division for AREVA. He was in charge of the Air blast (PK and PKV) refurbishing program in partnership with hydro-Quebec and introduced a unique administration system for the program (average of 35, 735 kV PK air blast circuit breaker per year). In 2005 he joined General Electric Company of Canada as a senior circuit breaker specialist and is in charge of the circuit breaker division of the Montreal service centre, responsible of the remanufacturing program for Oil circuit breakers
