Energy and Power
4 Factors To Consider When Selecting a Sectionalizer
Sectionalizers are (beside overcurrent relays, reclosers and fuses) one of the most used for distribution system protection. A sectionalizer is a device that automatically isolates faulted sections of a distribution circuit once an upstream breaker or recloser has interrupted the… Read more
Sep 16, 2015 | By Edvard Csanyi
Energy and Power
The Basics of Electrical Bus Protections
When we examine electrical protection schemes, the best place to start is with electrical bus protections, as they are the easiest to protect. They utilize the fundamental concept of the overcurrent relay (Figure 1). An overcurrent relay is an electromagnetic device in which current in… Read more
Sep 05, 2015 | By Edvard Csanyi
Energy and Power
Things About MCBs That Every Low Voltage Electrician Should Know
Miniature circuit breaker – MCB is a thermo-magnetic device, meaning that it has two methods of circuit interruption. A thermal mechanism, usually a bi-metallic strip, provides protection against moderate overcurrent. The heating action of the current causes the bi-metallic strip… Read more
Aug 22, 2015 | By Edvard Csanyi
Medium Voltage
Medium Voltage Earthing Systems – Arrangements and Comparison
First, let’s define the different medium voltage earthing systems and then compare the advantages and disadvantages of each one. Earthing systems in medium voltage can be differentiated according to the neutral point connection method. The various earthing systems in medium… Read more
Jul 03, 2015 | By Edvard Csanyi
Energy and Power
How to achieve selective coordination of circuit breakers
Selective coordination is often referred to simply as coordination. Coordination is defined in NEC® 240.2 as: “The proper localization of a fault condition to restrict outages to the equipment affected, accomplished by the choice of selective fault-protective devices.” It is… Read more
Jun 08, 2015 | By Edvard Csanyi
Energy and Power
The Philosophy Of Breaker Failure Protection
The separation of equipment into zones will only work successfully if the outputs of the protections can be guaranteed to do their job. This makes logical sense. For the bus protection in Figure 1 for example, the breakers X and… Read more
May 29, 2015 | By Edvard Csanyi
Medium Voltage
Current and voltage sensors as an alternative to traditional CTs and VTs
As an alternative for traditional primary current and voltage measurement techniques, the use of sensor technique is gaining field. This technique is typically applied to current and voltage measurement in medium-voltage metal-enclosed indoor switchgear. There are many undeniable advantages with… Read more
May 25, 2015 | By Edvard Csanyi
Metering
Understanding the ratios of magnetic HV instrument current transformers
The primary winding is a part of the network, carrying the actual load current. The transformer’s secondary circuits usually consist of several units, each of them having its own magnetic core and winding. The transformer has a rated current transforming… Read more
May 22, 2015 | By Edvard Csanyi
Electric Motor
The basics of built-in motor protection for engineers beginners
In order to avoid unexpected breakdowns, costly repairs and subsequent losses due to motor downtime, it is important that the motor is fitted with some sort of protective device. This article will deal with built-in motor protection with thermal overload… Read more
May 15, 2015 | By Edvard Csanyi
Energy and Power
3 Overcurrent Protective Device Ratings You MUST Properly Select
In order for an overcurrent protective device to operate properly, the overcurrent protective device ratings must be properly selected. These ratings include: Voltage rating Ampere rating and Interrupting rating – Minimum Interrupting Rating. If the interrupting rating is not properly selected,… Read more
May 08, 2015 | By Edvard Csanyi
Energy and Power
Nine Recommended Practices for Grounding
Grounding and bonding are the basis upon which safety and power quality are built. The grounding system provides a low-impedance path for fault current and limits the voltage rise on the normally non-current-carrying metallic components of the electrical distribution system…. Read more
Mar 06, 2015 | By Edvard Csanyi
Energy and Power
Ring Main Unit (RMU) as an important part of secondary distribution substations
Before getting into “What is RMU” question, let’s say a word about the distribution system where RMU is often used. Distribution systems encompass power lines that transport energy from the transmission network or other sources to consumers, along with the… Read more
Feb 11, 2015 | By Edvard Csanyi
Energy and Power
A real life analogy of the jurisdiction of the protection relay
Formally, a relay is a logical element which processes the inputs (mostly voltages and currents) from the system/apparatus and issues a trip decision if a fault within the protection relay‘s jurisdiction is detected. A conceptual diagram of relay is shown… Read more
Feb 09, 2015 | By Edvard Csanyi
Energy and Power
Voltage Imbalance Protection of Synchronous Generator (ANSI Code 60)
In an apparatus protection perspective, generators constitute a special class of power network equipment because faults are very rare, but can be highly destructive and therefore very costly when they occur. If for most utilities, generation integrity must be preserved… Read more
Feb 04, 2015 | By Edvard Csanyi
Electrical Lectures
Miniature Circuit Breakers (MCBs) For Beginners
This technical article focuses on the widely used miniature circuit breakers rated for 240 V or less. These are smaller and lower-rated versions of industrial-grade molded-case circuit breakers rated for 600 V or less. These miniature breakers, called air circuit… Read more
Jan 26, 2015 | By Edvard Csanyi
