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 | 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… 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… 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… 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… 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… 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… 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… 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… Read more

Mar 13, 2017 | Edvard

3 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… 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… 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… 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… 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… Read more

Mar 01, 2017 | Edvard