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
Few Aspects of Copper versus Aluminium
The constructions of aluminum wire and terminals have both been revised from past years. At one time the conductor was nearly pure aluminum, now they are all much stronger 8000 series alloys, with physical characteristics similar to copper. The wire… Read more
May 27, 2015 | By Edvard Csanyi
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
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
5 most common motor load types
Certain load types are characteristic in the industrial world. Knowing the load profile (speed range, torque and power) is essential when selecting a suitable motor and frequency converter for the application. Some common load types are shown. There may also… Read more
May 20, 2015 | By Edvard Csanyi
Important Guidelines To Startup and Shutdown a Large Generator
The purpose of this guidelines is to ensure the continuing operational integrity of generators. Operating conditions (startup and shutdown) that have forced units off-line or have damaged or shortened the life of turbine (or generator) components in the past are… Read more
May 18, 2015 | By Edvard Csanyi
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
Motor connection for clockwise and counterclockwise direction of rotation
Star-delta (in North America the designation “wye-delta” is commonly used instead) starting is the simplest method for reducing the starting current of a motor. The technique can be used with all squirrel-cage induction motors that are delta-connected for normal operation… Read more
May 13, 2015 | By Edvard Csanyi
Field data interface devices as eyes and ears of a SCADA system
Field data interface devices form the “eyes and ears” of a SCADA system. Devices such as reservoir level meters, water flow meters, valve position transmitters, temperature transmitters, power consumption meters, and pressure meters all provide information that can tell an… Read more
May 11, 2015 | By Edvard Csanyi
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
7 factors to consider when choosing single versus parallel generators
Paralleling is the synchronous operation of two or more generator sets connected together on a common bus in order to provide power to common loads as shown in Figure 1. In deciding whether a single or multiple generators should be installed… Read more
May 06, 2015 | By Edvard Csanyi
Maintenance and testing of overcurrent protective devices
When designing electrical distribution systems, required maintenance and testing of the overcurrent protective devices is a very important consideration. The electrical system reliability, component and circuit protection, and overall safety are directly related to the reliability and performance of the… Read more
May 04, 2015 | By Edvard Csanyi
Calculating the short circuit heating of busbars
Like all electrical circuits, busbars need to be protected against the effects of short-circuit currents. The open construction of busbars increases the risk of faults, e.g. by the ingress of foreign bodies into air gaps, and the risk of consequent… Read more
May 01, 2015 | By Edvard Csanyi