Electrical Lectures
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
High Voltage
Where Do We Use Arc Suppression Coil (Petersen Coil)?
The arc suppression coil (ASC), also known as Petersen coil, is used to compensate the capacitive earth fault currents supplied by outgoing feeders at a substation. The compensation can be either centralized or distributed. With the centralized design, one ASC… Read more
Jun 06, 2016 | By Edvard Csanyi
Energy and Power
Few Tips For Correct Protection Against Indirect Contact In TT System
An earth fault in a TT system originates the circuit represented in Figure 1. The fault current flows through the secondary winding of the transformer, the line conductor, the fault resistance, the protective conductor, and the earth electrode resistances (RA,… Read more
Jun 03, 2016 | By Edvard Csanyi
Cables
Shielding and Grounding Practices for Control Cables in EHV Substations
For several years, the increased application of solid-state devices for protective relaying and control and for electronic equipment, such as audio tones, carrier and microwave equipment, event recorders, and supervisory control equipment, in EHV substations has resulted in many equipment… Read more
May 20, 2016 | By Edvard Csanyi
Energy and Power
Differential protection – Proven technique for more than 50 years
The best protection technique now and for more than 50 years is that known as differential protection. Here the electrical quantities entering and leaving the protected zone or area are compared by current transformers (CTs). If the net between all… Read more
May 02, 2016 | By Edvard Csanyi
Energy and Power
Features of 3 circuit protection devices (MCB, RCCB and RCBO) you have probably forgotten
Traditionally, fuses were the main devices chosen for final circuit protection, up until the 1970’s when circuit breaker technology started to become dominant. Today, the three principle circuit protection devices are: Miniature Circuit Breakers (MCBs), Residual Current Circuit Breakers (RCCBs)… Read more
Apr 25, 2016 | By Edvard Csanyi
Energy and Power
What Would Be The Worst Type Of Three Phase Faults (And Why It Happens)
In a three phase power system, the type of faults that can occur are classified by the combination of conductors or buses that are faulted together. In addition, faults may be classified as either bolted faults or faults that occur… Read more
Apr 22, 2016 | By Edvard Csanyi
Power Quality
5 anomalies in AC power that can damage your home devices
In addition to lightning, there are a number of other disturbances that can come in on the AC power lines and damage equipment. Some surge protectors can reduce or eliminate damage from some of these perturbations. There is considerable confusion… Read more
Apr 11, 2016 | By Edvard Csanyi
Protection
3 Main causes of false differential current in transformer
Certain phenomena can cause a substantial differential current to flow, when there is no fault, and these differential currents are generally sufficient to cause a percentage differential relay to trip. However, in these situations, the differential protection should not disconnect the system… Read more
Mar 21, 2016 | By Edvard Csanyi
Energy and Power
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
Energy and Power
5 Means Of Identifying Grounded Conductors (By NEC 200 Article)
Latest NEC requirements state at least five means of identifying grounded conductors. So, let’s go through each of them // Sizes 6 AWG or smaller Sizes 4 AWG or larger Flexible cords Grounded conductors of different systems Grounded conductors of… Read more
Feb 13, 2016 | By Edvard Csanyi
Energy and Power
Arc Flash Hazard Calculation In 9 Steps Using IEEE 1584
The Institute of Electrical and Electronic Engineers (IEEE) published the IEEE 1584 “Guide for Performing Arc Flash Hazard Calculations”. It contains detailed methods and data that can be used to calculate arc flash hazards for the simplest to the most… Read more
Feb 12, 2016 | By Edvard Csanyi
Energy and Power
Where do electrical faults occur the most?
A fault is not a natural occurrence. It is an unplanned event which occurs unexpectedly. Electrical faults in an electrical installation or piece of equipment may be caused by: Negligence (that is, lack of proper care and attention), Misuse (that is,… Read more
Feb 01, 2016 | By Edvard Csanyi
Energy and Power
Important points about grounding of electronic equipment
Grounding electronic equipment for personal safety and clearing of faults is no different than that of any other equipment. Safe grounding requires fast opening of circuit breakers or fuses and minimization of voltage differences between exposed metal surfaces on all… Read more
Jan 29, 2016 | By Edvard Csanyi
Metering
Measurement of residual currents on a distribution feeder
The measurement of the earth fault or residual currents on a distribution system feeder can be done by the so-called summation connection, where the three current transformers, one in every phase, are connected and the summated current is brought to… Read more
Jan 22, 2016 | By Edvard Csanyi
