20 Simple Questions to Check Your Overcurrent Protection Knowledge
As you already know, reliable overcurrent protective devices, such as fuses and circuit breakers, prevent or minimize costly damage to transformers, conductors, motors, equipment, and the other many components and loads that make up a complete electrical system. As an… Read more
Jul 31, 2017 | By Edvard Csanyi
Automation of secondary distribution networks in rural areas
The challenges in network automation for rural areas are similar to those in urban areas, however the network topology may be very different. A typical conventional network topology is shown in Figure 1. Due to relatively sparse population, feeders are… Read more
Jul 12, 2017 | By Edvard Csanyi
Three earthing fault typologies and connection of the CB poles in a DC network
In order to break a short-circuit current in a d.c. system, it is necessary to connect the circuit breaker (CB) poles in a suitable way. To carry out this operation, it’s necessary to know the earthing typology of the plant…. Read more
Jun 05, 2017 | By Edvard Csanyi
Auto-reclose schemes for re-energising the line after a fault trip
Faults on overhead lines fall into one of three categories: transient, semi-permanent and permanent. 80-90% of faults on any overhead line network are transient in nature. The remaining 10%-20% of faults are either semi-permanent or permanent. Transient faults are commonly… Read more
May 15, 2017 | By Edvard Csanyi
Circuit breaker selections for low voltage installation (with discrimination)
The LV installation which forms the subject of this study is shown in figure 1 above. This study includes discrimination and coordination of protection between the LV equipment and the protection located upstream of each MV/LV power supply transformer. The… Read more
Apr 14, 2017 | By Edvard Csanyi
5 good examples of locking out HV/MV/LV structures and equipment
In all cases the choice of locks and safety positions requires prior analysis of the locking sequence to be applied in order to correctly define the requirement and clearly identify the related risks. Remember that “electric” locking systems are never… Read more
Feb 17, 2017 | By Edvard Csanyi
Gas insulated substation (GIS) versus Air insulated substation (AIS)
The metal-enclosed gas insulated switchgear> inherently follows the criteria for new substation design and offers a higher reliability and flexibility than other solutions. Due to the gas enclosed design, GIS is the most suitable solution for indoor and underground substations…. Read more
Dec 02, 2016 | By Edvard Csanyi
6 Adjustable Tripping Settings of a Circuit Breaker You MUST Understand
There are (at least) six basic adjustable tripping settings (functions) you really should understand in order to fully understand how circuit breaker actually works. All these adjustable functions actually shape the time-current curve of a circuit breaker and allows proper… Read more
Jun 10, 2016 | By Edvard Csanyi
The basics of selectivity (discrimination) between circuit breakers
On economical grounds and for the reason of reliability of the service, it is not always ideal to interrupt the supply to the installation in the case of a fault as fast as possible. That’s why we have the selectivity… Read more
Apr 04, 2016 | By Edvard Csanyi
Practical Considerations of LV/MV Private Substations
Private substations can often be considered as terminal type substations, i.e. substations where the MV line ends at the point of installation of the substation itself. They belong to the user and can supply both civil users (schools, hospitals, etc.)… Read more
Mar 04, 2016 | By Edvard Csanyi
The Basics Of Molded Case Circuit Breakers You MUST Know
Molded case circuit breakers are interrupting devices with self-contained, current-responsive elements. These breakers are assembled as an integral unit in a supported and enclosed housing of insulating material. Depending on the amount of protection required, these breakers can sense internally… Read more
Feb 27, 2016 | By Edvard Csanyi
The Basics Of Circuit Breaker Tripping Units
The main objective of circuit breaker tripping units and protective functions in general is to detect faults and to selectively isolate faulted parts of the system. It must also permit short clearance times to limit the fault power and the… Read more
Dec 21, 2015 | By Edvard Csanyi
Learn To Interpret Single Line Diagram (SLD)
We usually depict the electrical distribution system by a graphic representation called a single line diagram (SLD). A single line can show all or part of a system. It is very versatile and comprehensive because it can depict very simple… Read more
Dec 19, 2015 | By Edvard Csanyi
The Design Basics Of Motor Protection Circuit Breaker
Application-specific variations of the MCCB, these breakers combine the short-circuit and isolation functionality of the MCCB with the motor overcurrent protection of a traditional overload relay. MPCBs are UL 489 Listed as circuit breakers and verified as motor overload relays. These… Read more
Dec 07, 2015 | By Edvard Csanyi
7 guidelines to select correctly rated circuit breaker
The general procedure for the selection of correctly rated circuit breaker follows the following scheme of seven major questions you should answer. Let’s see the major questions: What is the task of the branch circuit or feeder? Which rated current… Read more
Dec 04, 2015 | By Edvard Csanyi
