Distribution of the MV neutral conductor right to the loads
4-wire systems are characterized by distribution of the MV neutral conductor right to the loads. This type of distribution is used in the USA and in certain countries influenced by… Read more
Dec 16, 2015 | By Edvard Csanyi
Protective relay – The brain that detects abnormal system conditions
For medium voltage circuit breaker applications, protective relay serve as the “brain” that detects abnormal system conditions and direct the circuit breaker to operate. They also serve to provide specialized… Read more
Dec 12, 2015 | By Edvard Csanyi
Learn How To Specify Current Transformers
Current transformers are used to supply information to the protective relays and/or current, power and energy metering “instruments”. For this purpose they must supply a secondary current proportional to the… Read more
Dec 05, 2015 | By Edvard Csanyi
HV/MV/LV Transformer Protection Schemes
Transformer protection should take into account the power, voltage, vector group and the importance of the unit within a particular system. Depending on these factors, the transformers can be assigned… Read more
Nov 28, 2015 | By Edvard Csanyi
Automatic transfer system explained in detail (operational requirements)
In a previous article I explained the role of the automatic transfer system and the operational requirements – three modes of operation: manual mode, automatic mode, and auto mode failure…. Read more
Nov 21, 2015 | By Edvard Csanyi
Automatic Transfer System (ATS) Explained in Details
Using the basic building blocks of utility power, system topology, on-site generation, and uninterruptible power supplies, the basic role of the automatic transfer system may now be defined. In this… Read more
Nov 20, 2015 | By Edvard Csanyi
Secondary Distribution Networks In Urban Areas
A high level of interconnection, either ring or mesh, to ensure a high degree of availability of supply to the consumer, characterises secondary distribution networks in urban areas. Domestic, industrial… Read more
Nov 04, 2015 | By Edvard Csanyi
Protection of A.C. Electrified Railways
Many regional, urban and high-speed inter-urban rail networks worldwide are electrified, to provide the motive power for trains (Figure 1). The electrification system serves as the contact interface for current… Read more
Oct 30, 2015 | By Edvard Csanyi
6 Voltages a Person Can Be Exposed To In a Substation
Figures 1 and 2 show the voltages a person can be exposed to in a substation. There are many definitions related to these voltages, but the following six are the… Read more
Oct 09, 2015 | By Edvard Csanyi
Surge Protective Devices In TN Systems (Guide For Low Voltage Electricians)
For “protection against electric shock under fault conditions“ in TN systems, overcurrent and residual current devices have been approved. For the use of surge protective devices (SPDs) this means that… Read more
Sep 25, 2015 | By Edvard Csanyi
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… Read more
Sep 16, 2015 | By Edvard Csanyi
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)…. Read more
Sep 05, 2015 | By Edvard Csanyi
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…. Read more
Aug 22, 2015 | By Edvard Csanyi
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… Read more
Jul 03, 2015 | By Edvard Csanyi
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,… Read more
Jun 08, 2015 | By Edvard Csanyi