High Voltage
An Example of Choosing 138 kV Line Circuit Breaker
To better understand a process of high voltage equipment selection, let’s discuss an example of choosing 138 kV Line #3 Circuit Breaker, shown in Figure 1, assuming that the following information about the system is available: The following information about… Read more
Jul 23, 2014 | By Edvard Csanyi
Power Substation
How To Locate Current Transformers in HV Substation
Current transformers are used for protection, instrumentation, metering and control. It is only the first function that has any bearing on the location of the current transformer. Ideally the current transformers should be on the power source side of the circuit… Read more
Mar 14, 2014 | By Edvard Csanyi
Energy and Power
Purposes and Examples of Safety Interlocking Devices
Most switchboards and motor control centres are fitted with a variety of electrical and mechanical safety interlocking devices. Their purposes are to protect against for example: Withdrawing the switching device while it is carrying load or fault current. Prevent the switching… Read more
Feb 05, 2014 | By Edvard Csanyi
Energy and Power
What’s Really Important When You’re Designing The Low Voltage Switchgear?
Here what’s important when you’re designing the low voltage switchgear: Device Application in the Supply Circuit Short-circuit strength Release (Trip Unit) Device Application in Supply Circuits (Coupling) Device Application in the Distribution Circuit Device Application in the Final Circuit The… Read more
Oct 07, 2013 | By Edvard Csanyi
Electric Motor
Sizing The DOL Motor Starter Parts (Contactor, Fuse, Circuit Breaker and Thermal Overload Relay)
In this technical article we’ll calculate the size of each part of DOL motor starter for the system voltage 415V, 5HP three phase household application induction motor, code A, motor efficiency 80%, motor RPM 750, power factor 0.8 and overload… Read more
Sep 11, 2013 | By Jignesh Parmar
High Voltage
Talking about HV shunt reactor switching (part 2)
Continued from first part: Talking About HV Shunt Reactor Switching (part 1) Scope (explained in previous part) Shunt reactors application (explained in previous part) Closing operation (explained in previous part) Opening operation Conclusions In the case of shunt reactors the… Read more
Jul 31, 2013 | By Nicola
High Voltage
Talking about HV shunt reactor switching (1)
These notes aim to give basic idea of the main criticalities related to HV shunt reactor switching, particularly in terms of voltage, and how such problems are faced and solved by modern switching technology. Content: Shunt reactors application Closing operation… Read more
Jul 29, 2013 | By Nicola
High Voltage
Commissioning of HV Panel – Operational and Functional Checkup
The main objective of the test is to check the proper operation function of the circuit breaker; in this test we do the following: This test is conducted by manual, Local and Remote. For the manual Operation test, we will… Read more
Jul 17, 2013 | By Edvard Csanyi
Low Voltage
Defining Size and Location of Capacitor in Electrical System (2)
Continued from part 1: Defining Size and Location of Capacitor in Electrical System (2) Size of circuit breaker (CB), fuse and conductor of capacitor bank: A. Thermal and magnetic setting of a circuit breaker B. Fuse selection C. Size of… Read more
Mar 11, 2013 | By Jignesh Parmar
Medium Voltage
Things You Should Know About Medium Voltage GIS
Environmental Concerns Safety Concerns Special Handling Procedures Installation Concerns Operation and Maintenance Concerns End of Life / Recycling Concerns Conclusion Medium voltage (5-38 kV) gas insulated switchgear (GIS) differs greatly from the medium voltage AIS – Air insulated switchgear commonly… Read more
Feb 20, 2013 | By Edvard Csanyi
High Voltage
High voltage substations overview (part 1)
High voltage substations are interconnection points within the power transmission and distribution systems between regions and countries. Different applications of substations lead to HV substations with and without power transformers: Step up from a generator voltage level to a high voltage… Read more
Jan 25, 2013 | By Emmanouil Angeladas
Energy and Power
Discrimination between residual current circuit breakers (RCCBs)
The operating principle of the residual current release is basically the detection of an earth fault current, by means of a toroid transformer which embraces all the live conductors, included the neutral if distributed. In absence of an earth fault,… Read more
Jan 11, 2013 | By Edvard Csanyi
Energy and Power
Short-Circuit Switching Capacity Definition
The switching capacity is the r.m.s value of a current at a given power factor cosφ as well as a given rated voltage at which a switchgear or a fuse can still shut-off under specified conditions in an operationally safe… Read more
Dec 20, 2012 | By Edvard Csanyi
Energy and Power
Using Protective Relay For Fighting Against Faults
Introduction to Protective Relay Working Principle of Protective Scheme What is Relay? Functions of Protective Relay Desirable qualities of protective relaying Terminology of protective relay History of Protective Relay Types of Relays Types of Relay based on Relay Operation Mechanism… Read more
Dec 17, 2012 | By Jignesh Parmar
High Voltage
Methods of Controlling Lightning Overvoltages in HV
For well shielded transmission lines, the backflashover condition, close to the substation, is of prime concern for determining the location and number of surge arresters required to achieve insulation coordination of the substation for lightning surges. The risk of a… Read more
Dec 08, 2012 | By Edvard Csanyi
