Technology Switchgear And Control Handbook Pdf


Thursday, June 27, 2019

Switchgear and Control Handbook. Download PDF Electrical systems analysis and design for industrial plants Book. ELECTRICAL Systems for Computer. The One Expert Source for Switchgear and Control Information and Data. Here is the only practical reference tool you need to specify, select install, and maintain. pages - $ (hardback), These proceedings are from the Op- tical Society of America Conference on. Applications of High Field and Short.

Switchgear And Control Handbook Pdf

Language:English, Spanish, Dutch
Genre:Children & Youth
Published (Last):18.10.2015
ePub File Size:15.56 MB
PDF File Size:14.34 MB
Distribution:Free* [*Regsitration Required]
Uploaded by: JOSEPHINE

CIRCUIT BREAKER AND SWITCHGEAR HANDBOOK VOLUME The integrity of the low-voltage control and protective device circuitry is critical. 4 c. Switchgear/PCC Fundamentals. Niel Miele, PE, LEED AP. PACS Industries Transformer. • Circuit Switches/Breakers. • Command and Control System. This is the second edition of the Handbook of Electrical Design Details (HEDD), orig- inally published in .. and control wiring are represented by broken lines.

The incident energy level is used to determine the flash protection boundary the surrounding area where the incident energy is equal to or greater than 1. This incident energy level exposes personnel to potential second-degree burns. The incident energy also is used to determine the appropriate PPE required for the application. The incident energy level is dependent on various factors, including system operating configurations, voltage, length of the arc, arcing current, protective device settings, time to clear, and distance from arc fault to workers.

In a given work environment, the calculation needs to be performed at various locations where any of these variables will change. Note that the highest level of arcing current does not always result in the highest incident energy level. A lower level of current that results in a longer arcing duration may cause higher incident energy levels at the workers location.

Care must be exercised to prescribe the appropriate PPE for the application. Overly conservative requirements can restrict worker movement, vision, hearing, and comfort level unnecessarily. This in itself can be the cause of an unsafe situation.

Regardless of the incident energy level, additional practical steps can be taken to improve the safety level of the work environment.

These include the use of arc resistant switchgear, provisions for closed door or remote circuit breaker racking and operation, and special protective schemes to minimize arc fault durations and magnitudes.

EEMAC G defines three accessibility types: Type A: switchgear with arc resistant construction at the front only Type B: switchgear with arc resistant construction at the front, back and sides Type C: switchgear with arc resistant construction at the front, back and sides, and between compartments within the Circuit Breaker and Switchgear Handbook - Vol. This document is currently being reviewed by the working group and will be refined further in the next revision. Part of this revision process will include an attempt to harmonize the requirements with the current IEC practices.

IEEE C Chapter 17 captures the erection and commission requirements of switchgear. All aspects regarding requirements and precautions for erection and commissioning of indoor and outdoor switchgear for satisfactory performance have been covered in this chapter.

The operation and maintenance aspects of switchgear under various conditions have been covered in Chapter It provides useful information about the dos and donts to be followed during site work, inspection and on maintenance procedures.

Chapter 19 briefly covers the significance and procedures used for different tests with as many practical cases as possible. Chapter 20 is a compilation of details of all major standard organisations and various applicable standards for switchgear products. This serves as readily available information for practising engineers. The details regarding statutory requirements and electricity rules covered under Chapter 21 provides necessary guidelines to switchgear designers and site engineers to ensure safety of personnel and property.

The book reflects the expertise gained by BHEL in the field of switchgears and offers a wide and thorough coverage. The work here is informative as it follows a practical approach and highlights all salient features of switchgear. I am confident that the book will serve as a useful reference for all practising engineers and students. BHEL for publishing this book. This book is a result of collective effort of experts in the field of switchgears at BHEL, a leading switchgear manufacturer in India.

Thanks are due to all the authors who took pains and contributed chapters to it. Selecting the chapters to cover various aspects in detail and at the same time integrating the entire material and presenting it as a homogenous whole was an uphill task. Our grateful thanks are due to Shri S G Dehspande, an editorial committee member, who put in exemplary and untiring efforts without which this book could not have taken shape. We would like to extend our sincere thanks to Prof. Thanks are also due to Tata McGraw-Hill for publishing this book.

Shri S G Deshpande, Sr. M P Soni, Addl. N N Shenoy, Addl.

General Manager, has worked on design of tap changer for 10 years and on switchgear application for 20 years. S K Sahasrabudhe, Sr. General Manager, has worked for 25 years in design and development of medium voltage switchgear. A K Murgai, Sr. General Manager, has worked for 25 years in design of control and protection for power system application. Santosh Kumar, Dy. M K Shrivastava, Dy.

Neelam Bhogal, Dy. Manager, has worked for 15 years on design of motor crane control and for five years in the design of outdoor switchgear and auto-recloser sectionalizer. Sanjay Dhavle, Manager, has worked for 12 years in switchgear application. Vivek Johri, Dy. H R Patel, Dy.


Manager, has worked for 13 years in switchgear design and application. M A Khan, Sr. Divya Bhat, Sr. Manisha Singh, Sr. Murtaza Hussain, Sr. Yellaiah Babu B, Sr. The assemblies of such devices and equipment with associated inter-connections, accessories, enclosures and supporting structures, intended, in principle, for use in connection with the generation, transmission, distribution and conversion of electric energy also form a switchgear.

We all are familiar with low voltage switches and re-wireable fuses in our homes. A switch is used for opening and closing an electric circuit while a fuse is used for over-current and short-circuit protection. Every electric circuit needs a switching device and a protective device.


The switching and protective devices have been developed in various forms. Thus switchgear can be taken as a general term covering a wide range of equipment concerned with the switching, protection and control of various electrical equipments. Similarly, switching and current interrupting devices play a significant role in the modern electrical network, right from generating stations, transmission sub-stations at different voltages, distribution sub-stations and load centres.

The switching device here is called a circuit breaker. The circuit breaker, along with associated devices for protection, metering and control regulation, is called a switchgear. A switchgear has to perform the functions of carrying, making and breaking the normal load current like a switch. In addition, it has to perform the function of clearing the fault current for which sensing devices like current transformers, potential transformers and various types of relays, depending on the application, are employed.

There also has to be provision for metering, controlling and data, wherein innumerable devices are used for achieving the switchgear function.

Related titles

Thus a switchgear can include a circuit breaker, current transformers, potential transformers, protective relays, measuring instruments, switches, fuses, MCBs, surge arrestors, isolators and various associated equipments. Switchgears are necessary at every switching point in the power system for the reasons mentioned above. There are several voltage levels and fault levels between the generating stations and final load points. Hence in the various applications, the requirements of switchgears vary depending on the location, ratings and local requirements.

Besides the supply network, switchgear is required in industrial works, industrial projects, domestic and commercial buildings. During the last four decades, the switchgear industry has seen the transition of four switching technologies, viz. Finally, the emergence of environment-friendly vacuum technology in medium voltage switchgears and of SF6 gas technology in high voltage and gas insulated sub-station GIS promises bring stability.

The technological aspects of medium and high voltage circuit breakers ranging from 3. The technological backgrounds and advantages of various switching technologies, viz. Arc energy and arc quenching play a very important role in an interrupting media. The arcing phenomenon is dealt with in detail to understand and establish the superiority of a technology.

Different types of mechanisms viz.

The type of mechanism in a circuit breaker depends upon the energy and speed required for arc interruption. Being simple and economical, the spring mechanism has been popular in both medium and high voltage switchgears. Magnetic actuators are now being introduced in medium voltage circuit breakers up to 12 kV, 40 kA due to their inherent advantages of long life, suitability for a large number of operations, maintenance-free operation and smaller number of components.

Switchgears for low voltage applications are rated up to V ac and V dc.

The requirements of conventional switchgears and new trends for various applications like incomers, sub-incomers and feeder protections are briefly discussed in Chapter 2.

Switchgears for medium voltage applications are rated from 3. Medium voltage switchgears are mainly used for the distribution of electrical energy connected to various electrical networks.

Chapter 3 deals elaborately with the historical background of minimum oil circuit breakers, bulk oil circuit breakers, air magnetic switchgears, SF6 gas insulated switchgears, and the latest trends in vacuum switchgear and gas insulated switchgears. This chapter also provides information about various forms of construction in metal enclosed, metal clad and porcelain clad design. The design aspects, related to current rating, temperature rise limits, short-circuit current requirements, vibrational stresses and insulation aspects are covered elaborately.

High voltage circuit breakers ranging from 66 kV to kV class are covered in Chapter 4. This chapter deals with the historical background, present status of technological developments and the future outlook of high voltage switchgears. This chapter also provides insight into various interrupting media like air, oil and SF6 gas which have been successfully used in the development of high voltage circuit breakers.

The latest trends in the design of SF6 gas circuit breakers and operating mechanisms are also discussed.

System requirements covering important duties like short-circuit terminal fault , short line fault, transformer magnetising current, energisation and breaking of long transmission lines, breaking of capacitive current and out-of-phase switching are also elaborately discussed in this chapter. Sub-stations and switchyard equipments like circuit breakers, disconnectors, earth switches, busbars, CTs and PTs are metal encapsulated and pressurised with SF6 gas.

The use of GIS equipments reduces requirement for space and improves reliability, thus increasing their popularity for application in metro cities and hydro stations where the costs of space and construction are very high.

Auto reclosures and sectionalisers are used in the distribution networks of medium voltage switchgears upto 33 kV class. These equipments are useful for the fast automatic restoration of supply following transient faults in the system due to frequent lightning surges and in areas where power lines run through forests and trees. These equipments are extensively used in the continents of America and Australia due to their distinct advantages over conventional switchgears.

Although this product has not yet gained popularity in India, it has great potential for rural electrification and power distribution to important load centres in India. Chapter 6 is entirely devoted to this topic in view of its potential importance.


This chapter deals with the technical specifications, construction, and technological aspects of auto re-closures and sectionalisers, along with case studies for various applications. Instrument transformers current and voltage are used in switchgear installations for the measurement of electrical parameters for protection and metering purposes. Chapter 7 provides an overview of instrument transformers while covering theories of technical parameters that define terminologies, design and constructional aspects, important design considerations, application aspects, and testing requirements.

Due to the existence of a large number of key system parameters, numerous verieties of CTs and VTs are being used. This chapter also provides suggestions for the standardisation and cost reduction of instrument transformers. With the emergence of numerical technology in the relaying and metering field, current and voltage sensors are replacing conventional CTs and VTs.

This chapter also briefly describes current sensors Rogowski coil and voltage sensors. These are used to protect the sub-station equipments from temporary over-voltages, switching impulses, and lightning impulses, and to a certain extent, very fast transient over-voltages.

Lightning arrestors, surge capacitors, surge suppressing reactors, and thyrite resistors with series gaps were used in the past for this purpose. Innovation in this field has resulted in the advent of two commonly used types, viz. Chapter 8 deals with the various types of surge arrestors, their characteristics, and construction and application aspects.

Protective relays are vital parts of the switchgear equipment.

The function of a protective relay is to initiate a signal to circuit breakers for disconnecting the element of the power system when it develops a fault. There have been rapid developments in relaying technology during the last two decades. The most important advancement has been due to the advent of computer technology which has helped in the development of numerical relays. Chapter 9 details various relay technologies like electromechanical, static, microprocessor-based, micro-controller-based and numerical technologies.

Although all the technologies are presently in use, numerical relay technology is gaining popularity over the others due to its communication capabilities which facilitate integrated control, protection and metering features.

These are detailed in Chapter 10, which discusses the application of medium voltage switchgears.All hardware should be checked for tightness. They are generally used at the outlet of high power generators MVA to MVA in order to protect them in a sure.

During interruption of high interrupting currents. The remanufactured equipment utilizes vessels fabricated from steel plates. Many scientists are concerned about what is being characterized as a global warming trend.

Subpart S mandates the requirements. This stage is characterized by wave motion and possible under-pressure with a duration of 5 to 10 milliseconds.

Geometric factors include sharp edges on conductors. Non exposed sides are excluded in type B. The driveshaft crank arms should be checked to verify that they toggle in both the open and close directions.