Energy and Power
Twelve ultimate mistakes when selecting circuit protection for low-voltage equipment
To be honest, a circuit breaker is fairly simple device. However, the process of specifying circuit protection is often complicated and unclear, leading many engineers to either include insufficient or excessive protection in their equipment designs. Insufficiently protected circuits expose… Read more
Jan 08, 2024 | By Edvard Csanyi
Power Substation
Close and charging motor control circuits for a power circuit breaker explained in detail
This technical article deals with schematics of close and charging motor control circuits for a medium-voltage circuit breaker. The proper functioning of MV switchgear depends on control circuits. For the switchgear to operate properly, the integrity of these control circuits… Read more
Feb 13, 2023 | By Edvard Csanyi
Protection
Generator synchronizing check protective function (ANSI 25 code)
One of the easiest way to damage a generator is to synchronize or parallel out of phase with the electrical system. Out-of-phase synchronizing operations can damage or reduce the remaining life of generator rotors and stationary components. Angular differences as… Read more
Mar 22, 2017 | By Edvard Csanyi
High Voltage
Main and Transfer (Inspection) Bus Arrangement commonly used in AIS
The main and transfer bus configuration connects all circuits between the main bus and a transfer bus (sometimes referred to as an inspection bus). Some arrangements include a bus tie breaker and others simply utilize switches for the tie between… Read more
Aug 13, 2014 | By Edvard Csanyi
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
Energy and Power
The main components of an oil circuit breaker and how does it interrupt the arc
They are simple in construction. The major parts of a minimum oil circuit breaker excluding the poles are the base frame,the drive which is constructed as a stored energy opening and closing mechanism (the operating mechanism). The opening spring of… Read more
Jul 24, 2012 | By Edvard Csanyi
Medium Voltage
Field Inspection of New Medium-Voltage Switchgear
Step Description of what you should do 1.1 Check switchgear assembly for alignment, levelness, and tightness of all bolting. 1.2 Check all equipment for the removal of blocking, supports, temporary ties, and temporary jumper wires. 1.3 Check control power transformer… Read more
Jul 16, 2012 | By Edvard Csanyi
Energy and Power
Definitions from the Standard UL 489 (MCCB)
The requirements of this standard cover molded-case circuit breakers (MCCB), circuit breaker and ground-fault circuit-interrupters, fused circuit breakers, and accessory high-fault protectors. These circuit breakers are specifically intended to provide service entrance, feeder, and branch circuit protection in accordance with… Read more
Jul 12, 2012 | By Edvard Csanyi
Low Voltage
Assemblies of switchgear and control panels (3)
Continued from 2nd part of article: Assemblies of switchgear and control panels (part 2) Now coverage of distribution panels and switchboards will be presented including molded case circuit breakers (MCCB), safety switches, panelboards, multimetering equipment, ground fault circuit interrupters. Most of the… Read more
Jun 30, 2012 | By Edvard Csanyi
Medium Voltage
Bus Switching Configurations In Air Insulated Substations (AIS)
Various factors affect the reliability of a substation, one of which is the arrangement of the switching devices. Arrangement of the switching devices will impact maintenance, protection, initial substation development, and cost. There are six types of substation bus switching… Read more
May 05, 2012 | By Edvard Csanyi
Energy and Power
The Need for Breaker Failure Protection
Circuit breakers are strategically located in power systems to connect circuits and electrical apparatus. Circuit breakers are commanded to open and close by protection and control systems that monitor conditions on the power system. Protection systems are coordinated so that… Read more
Jan 01, 2012 | By Edvard Csanyi
High Voltage
AIS – Air insulated substations
In large, modern AC power systems, the transmission and distribution systems function to deliver bulk power from generating sources to users at the load centers. Transmission systems generally include generation switchyards, interconnecting transmission lines, autotransformers, switching stations, and step-down transformers…. Read more
Sep 06, 2011 | By Edvard Csanyi
Energy and Power
Time-Current Curves explained in details
Time-current curves are used to show how fast a breaker will trip at any magnitude of current. The following illustration shows how a time-current curve works. The figures along the bottom (horizontal axis) represent current in amperes. The figures along… Read more
Dec 07, 2010 | By Edvard Csanyi
