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 measure reactive power at the… Read more
Mar 31, 2017 | Edvard
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 are not successfully isolated from… Read more
Mar 29, 2017 | Edvard
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 asset or process. In order… Read more
Mar 27, 2017 | Edvard
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 requirements these are destined for,… Read more
Mar 24, 2017 | Edvard
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 life of generator rotors and… Read more
Mar 22, 2017 | Edvard
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 protection and connection of capacitors… Read more
Mar 20, 2017 | Edvard
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 total effect of parallel loads…. Read more
Mar 17, 2017 | Edvard
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 L2 common) normally enter the… Read more
Mar 15, 2017 | Edvard
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 Higher motor cost Higher controller… Read more
Mar 13, 2017 | Edvard
Three performance factors you must consider when sizing batteries
Batteries need to be sized correctly to be able to feed the required load for the required time, and a number of factors need to be decided to be able to optimize the battery for… Read more
Mar 10, 2017 | Edvard
Never underestimate electrostatic discharge (ESD) while working with data networking equipment
Let’s start with basics you probably already know, but nevertheless. It’s important to explain the basics first. Electrostatic Discharge (or ESD) refers to the transfer of electrostatic charge between bodies at varied voltages that is… Read more
Mar 08, 2017 | Edvard
The essentials of synchronous machines in power distribution networks
Synchronous machines can be used as generators or motors. They are of 3-phase construction, even though some special exceptions can be found. A bulk of the applications are within power ranges roughly varying from a… Read more
Mar 06, 2017 | Edvard
Voltage drop calculation methods with examples explained in details
The first consideration for voltage drop is that under the steady-state conditions of normal load, the voltage at the utilization equipment must be adequate. In addition to steady-state conditions, voltage drop under transient conditions, with… Read more
Mar 03, 2017 | Edvard
Performing power factor test on dry-type transformer during commissioning
The power factor test is a maintenance test used to determine the insulation system dielectric power loss by measuring the power angle between an applied AC voltage and the resultant current. Power factor is defined… Read more
Mar 01, 2017 | Edvard
