Energy and Power
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… Read more
Apr 14, 2017 | By Edvard
Energy and Power
Six network operating conditions under which ferroresonance can occur
Due to the multitude of various sources of capacitances and non-linear inductances in a real power network and the wide range of operating conditions, configurations under which ferroresonance can occur… Read more
Apr 12, 2017 | By Edvard
Energy and Power
8 essential relay operating principles of catching faults
In general, as faults (short circuits) occur, currents increase in magnitude, and voltages go down. Besides these magnitude changes of the AC quantities, other changes may occur in one or… Read more
Apr 10, 2017 | By Edvard
Energy and Power
Three main techniques for mitigating step and touch potential hazards
Mitigating step and touch potential hazards is usually accomplished through one or more of the following three main techniques. Understanding the proper application of discussed techniques is the key to… Read more
Apr 07, 2017 | By Edvard
Electrical Lectures
How good are you at reading electrical drawings? Take the quiz.
Every electrician, in every branch of electrical work, will need to consult and understand the information presented on electrical drawings to locate the various outlets, the routing of circuits, the… Read more
Apr 05, 2017 | By Edvard
Energy and Power
Two main functions of an earth electrode and its installation parameters
The prime function of an earth electrode is the protection of persons. That’s it. It is a fact that we live on Earth! And it is vital to earth exposed… Read more
Apr 03, 2017 | By Edvard
Energy and Power
Wiring of power factor relay on LV and MV side (circuit diagrams)
In order to measure electrical power the relay needs to receive the line voltage and current from a current transformer (CT) installed close to the metering point, if possible. To… Read more
Mar 31, 2017 | By Edvard
Energy and Power
Five protection relay types used to detect grid disturbances and isolating
Consider a medium voltage distribution system having local generation (e.g., captive power generation) as shown in figure 1 which is also synchronized with the grid. During grid disturbance, if plant generators… Read more
Mar 29, 2017 | By Edvard
Energy and Power
Top six solutions to achieve a high level of energy efficiency in buildings
Energy efficiency in commercial buildings involves providing a given level of performance, cost, quality, availability, and comfort at a minimal level of energy usage throughout the lifecycle of a given… Read more
Mar 27, 2017 | By Edvard
Medium Voltage
The analysis of four network schemes in terms of reliability and protection
Before sizing an electric network, the single-line diagram of the electric network must be defined on the basis of: Load – it is considered fundamental to establish the true user and service… Read more
Mar 24, 2017 | By Edvard
Protection
Generator synchronizing check protective function (ANSI 25 code)
One of the easiest way to damage a generator is to synchronize or parallel out of phase with the electrical system. Out-of-phase synchronizing operations can damage or reduce the remaining… Read more
Mar 22, 2017 | By Edvard
Energy and Power
Installation, protection and connection of capacitor banks
In an low voltage electrical installation, capacitor banks can be installed at three different levels: Global installation Segment (or group) installation Individual (or single) installation After installation ways, we’ll discuss about… Read more
Mar 20, 2017 | By Edvard
Electrical Lectures
What is the complex power and how it figures in power analysis
Considerable effort has been expended over the years to express power relations as simply as possible. Power engineers have coined the term complex power, which they use to find the… Read more
Mar 17, 2017 | By Edvard
Industrial Automation
PLC power supply and safety (emergency) circuits requirements
The source for a PLC power supply is generally single-phase and 120 or 240 VAC. If the controller is installed in an enclosure, the two power leads (L1 hot and… Read more
Mar 15, 2017 | By Edvard
Electric Motor
Why overmotoring an application is not such a good idea
In many instances, the practice has been to overmotor an application, i.e., to select a higher-horsepower motor than necessary. The disadvantages of this practice are: Lower efficiency Lower power factor… Read more
Mar 13, 2017 | By Edvard
