GENERAL ARTICLES ABOUT CIRCUIT BREAKER TESTING
Measuring 60HZ AC Signals with less than 10 volts peak-to-peak amplitude
Using the general-purpose analog inputs (channels 3 and higher) on the ZENSOL CBA-32P, it is possible to measure AC voltages where the peak-to-peak amplitude is less than 10 volts. It is necessary to assemble a special circuit to obtain the desired results.
Direct connection
If a transformer’s sine wave output is directly connected to an analog input, as shown in Figures 1 and 2, a basic problem already shows itself:
Troubleshooting Examples
By definition, a circuit breaker timing test is the process of measuring the mechanical operating times with the goal of verifying, analyzing and validating the proper function of the circuit breaker.
The importance of timing tests is particularly critical in maintaining the reliability of the transport and distribution network, and also in the safety of the personnel employed to maintain and operate the network protection apparatus.
Using test execution and analysis tools, such as the CBA-32P, by Zensol, which is driven by the CBA Win© software, and with the experience acquired in the field, it is possible to determine, with remarkable accuracy, the nature of the problems that affect circuit breaker performance even before disassembling the apparatus.
However, timing tests are not limited to tests conducted after the circuit breaker fails (corrective maintenance). In the preventive maintenance strategy, the breaker is subject to regular timing tests to detect trends in the degradation and aging of the equipment, so that corrective action may be applied before the problems become a danger to the network or to the personnel.
Breaker timing
1.1 THE ELECTRIC NETWORK
Electricity is a natural phenomenon. It is a part of matter as negatively charged electrons and positively charged protons.
Generating stations, usually located in remote areas far from the main centers of consumption, generates it by transforming other forms of energy (mechanical, thermal, solar, nuclear, etc.).
Electricity thus produced is transported via the power transmission lines and distributed to consumers via the distribution grid.
The electrical power must always be available, without interruption, to the consumer, even if the consumer does not use it continuously.
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Related products: CBA-32P
Transducers installation examples
Introduction
One of the main difficulties in measuring the displacement on a circuit breaker is the position of the transducer and the attachment of the mechanical base on the breaker.
For more theoretical information on displacement tests and their interpretation, a thorough explanation may be found in the article “Displacement tests” in the Sharing Knowledge section.
An expert system for acoustic diagnosis of power circuit breakers and on-load tap changers
Article from Expert Systems with Applications – olume 42, Issue 24, 30 December 2015, Pages 9426–9433
Abstract
Most of the faults on power Circuit Breakers (CBs) and On-Load Tap Changers (OLTCs) on high voltage transformers are of mechanical origin. Mechanical malfunction, mechanical wear and other types of abnormal behaviors can be detected as changes in the acoustic signatures. In this paper, an Expert System (ES) with the addition of a signal processor module and factual database module to the conventional ES has been proposed for the diagnosis of CBs and OLTCs. The feature extraction of the acoustic signatures has been done by decomposing them into voiced and silent portions in time domain and through FFT spectrum analysis in frequency domain. The OLTC’s motor current has been decomposed into inrush, steady-state and extended currents to locate the cause of different anomalies in the OLTCs and acoustic-current pair has been used for the synchronization testing. Each extracted feature of the testing signal has been compared to the similar feature of a reference signal to not only identify the health of the testing device but also to locate the cause of each anomaly. Several test signals have been compared against the reference signature and the proposed expert system has proved to be a suitable, effective and reliable system for the acoustic diagnosis of OLTCs and CBs.
Related products: CBV-32
Maintenance of MV and HV Power Circuit Breakers
Article from Electric Energy T&D, Magazine – May-June 2006 Issue
Preface
This article is the first in a series of articles that will help to bring light to the maintenance practices presently applied to power circuit breakers.
Related products: CBA-32P
Maintenance Programs of MV and HV Power Circuit Breakers
Article exposing a summarized description of a typical maintenance program’s structure for medium to high voltage breakers, along with the advantages of following a good maintenance program.
Related products: CBA-32P
A Thorough Examination of Circuit Breaker Health
Hydro-Québec TransÉnergie explores alternative diagnostic methods in its high-voltage circuit breaker maintenance program. Covered topics include dynamic contact-resistance measurement, arcing contact misalignment, vibration analysis and more.
Breaker Diagnosis Examples
Four chapters of information describing electric networks and maintenance strategies, circuit breakers and potential problems, and solutions to detect these problems.
Related products: CBA-32P
AC/DC Voltage Test
Using the general-purpose analog inputs (channels 3 and higher) on the ZENSOL CBA-32P, it is possible to measure AC voltages where the peak-to-peak amplitude is less than 10 volts. It is necessary to assemble a special circuit to obtain the desired results.
Related products: CBA-32P
ARTICLES ABOUT TIMING BREAKER TESTING
Importance of breaker timing and testing
Breaker timing
“It is a necessity to time each breaker, in order to have its functional signature. Incorrect operation can have disastrous consequences on the equipment or the substation personnel, out of service losses of revenue and the repair costs… ”
Related products: CBA-32P
ARTICLES ABOUT MOTION TESTING
Ensures good contact motion in the Circuit Breaker
Transducers Installation Examples
Consists of numerous mounting examples of different rotary transducers on more then a dozen types of breakers including ABB, Areva, GE, etc…
The Displacement Curve
“Whenever it is possible, a point-by-point measurement of the movement of the internal components of the circuit breaker, from the beginning of the movement until it comes to a complete stop, traces a curve called a DISPLACEMENT CURVE.”
DYNAMIC RESISTANCE MEASUREMENT TESTING
Measures the Dynamic Resistance of Breaker Contacts
Electrical Contacts in MV & HV Power Circuit Breakers
In the present article you will find a summarized description of the different types of electrical contacts used in power circuit breakers, the major risks to their proper operation and the principal tests used to verify their condition.
Make/Break Contacts in Power Circuit Breakers
“The interruption of electric power circuits has always been an essential function, especially in cases of overloads or short circuits when immediate interruption of the current flow becomes necessary as a protective measure. This means of interruption soon became inadequate and special devices called circuit breakers had to be developed”.
A New Measurement Method of the Dynamic Contact Resistance of HV (pdf)
The following paper presents a new dynamic-contact-resistance measurement method that has been validated by field tests which were performed on air-blast and SF6 gas circuit breakers.
A Complete Strategy for Dynamic Contact Resistance Measurements on on HV Circuit Breakers (pdf)
The following paper proposes a complete strategy for conducting DRM on high-voltage CBs based on three relevant parameters: breaker contact speed (low or rated), injected current values (100–2800 A DC), and the presence of metallic fluorides deposited on breaker contacts.
FIRST TRIP ON LINE TEST
Capture the FIRST trip of your Circuit Breaker
Related products: zft
VIBRATION TESTING
The Vibration Technology applied to Circuit Breaker Testing
Application Note for vibration method applied on voltage regulator
Article for know what kind of voltage regulator signature we obtain and see if we can use the TAP-4 as a diagnostic instrument as it is commonly used for on load tap changers in transformers.
Related products: Tap 4
Vibro-Acoustic Testing Applied on Tap Changers and Circuit Breakers (pdf)
Article describing a method to detect problems on high voltage circuit breakers and tap changers using vibro-acoustic analysis.
Related products: Tap 4 CBV
Improved vibration analysis on circuit breakers (pdf)
This paper deals with the successful application of vibration analysis for circuit-breaker (CB) diagnostic testing with the aim of detecting mechanical anomalies in CB drive mechanisms and other moving parts in the interrupting chamber.
Related products: CBV
Detecting mechanical problems using vibration measurements
The vibro-acoustic diagnostic method is a very efficient way to track down mechanical problems in circuit breakers, such as very quick operations that generates high accelerations and decelerations that put the various operating mechanism components under very difficult stresses.
Related products: CBV
Acoustic diagnosis of high voltage circuit breakers
A non-invasive technique for assessing the condition of circuit-breakers by considering the acoustic signals generated during non-energized switching is described.
Related products: CBV
Vibration analysis for diagnostic testing of circuit breakers
In order to assess the feasibility of vibration analysis for diagnostic testing of high-voltage circuit-breakers a comprehensive field test program had been carried out. Vibration patterns from 31 breaker
Related products: CBV
Continuous Monitoring of Circuit breakers Using Vibration Analysis
This paper reports the results from three years of continuous condition monitoring of high-voltage circuit breakers (CBs) using vibration analysis. More than 1000 vibration patterns
