Energy and Power
3 earthing fault typologies and connection of the CB poles in a DC network
In order to break a short-circuit current in a d.c. system, it is necessary to connect the circuit breaker (CB) poles in a suitable way. To carry out this operation,… Read more
Jun 05, 2017 | By Edvard
Energy and Power
12 installation tips for implementing a good residual protection
All installations have an earth leakage current that is mainly due to the conductor’s capacitive leakage and to anti-parasitic or EMI filtering capacitors, for example class I equipment. The sum… Read more
Jun 02, 2017 | By Edvard
Electric Motor
Selecting the suitable frequency converter and motor for these 3 applications
The motor is selected according to the basic information about the process. Speed range, torque curves, ventilation method and motor loadability give guidelines for motor selection. Often it is worth… Read more
May 24, 2017 | By Edvard
Energy and Power
Troubleshooting of a telemetry system (from RTU to the SCADA computer facilities)
This technical article reviews certain methodologies that may be followed for effective troubleshooting of a telemetry system from the digital or analog field input/output at the RTU to the computer… Read more
May 19, 2017 | By Edvard
Electrical Lectures
How to calculate number of steps & reactive power of the capacitor banks
Depending on the size of a compensation unit, it is assembled with capacitors of equal size (in bigger units) or of different size. A unit with a total reactive power… Read more
May 17, 2017 | By Edvard
Energy and Power
Current sensors as the eyes of RCD and tips for their correct installation
All residual current devices are made up of at least two components. First component act as the eyes of RCD – sensors – must be able to supply an electrical signal… Read more
May 12, 2017 | By Edvard
Energy and Power
How to recognize harmonics symptoms – What to look for and where to look?
Finding harmonics problem is relatively easy once you know what to look for and where to look. Harmonics symptoms are usually anything but subtle. This technical article provides some basic… Read more
May 10, 2017 | By Edvard
Energy and Power
The attached rod technique – better than fall-of-potential ground testing method
Fall-of-potential testing is extremely reliable, highly accurate, conforms to IEEE 81 and gives the operator complete control over the set-up. Unfortunately, it is exceedingly time consuming and labor intensive, and… Read more
May 03, 2017 | By Edvard
Energy and Power
Protection of capacitor banks by fuses during energization and operation
Stress specific to the protection of capacitor banks by fuses, which is addressed in IEC 60549, can be divided into two types: Stress during bank energization (the inrush current, which is very… Read more
May 01, 2017 | By Edvard
Energy and Power
Why and where do internal faults happen in substation transformers
Transformers are subjected to many external electrical stresses from both upstream and downstream that can lead directly to internal fault(s). The consequences of any failure can be very great in… Read more
Apr 28, 2017 | By Edvard
Energy and Power
Typical power supply schemes for standby and production generator sets
The main types of prime movers used in engine driven generator sets for industrial sites and commercial buildings are Diesel engines, gas turbines, and steam turbines. Turbines are used mainly… Read more
Apr 26, 2017 | By Edvard
Energy and Power
The most frequent errors in specifying current transformers (CTs)
Current transformers (CTs) form an essential link within the protection chain of electrical networks. Their specification, even if it is handled by specialists, often includes errors and is insufficiently optimized…. Read more
Apr 24, 2017 | By Edvard
Energy and Power
Network harmonics analysis – Installation with 6-pulse rectifier, capacitors & filters
The diagram in figure 1 represents a simplified network comprising a 2,000 kVA six-pulse rectifier, injecting a harmonic current spectrum, and the following equipment which will be considered consecutively in three… Read more
Apr 21, 2017 | By Edvard
Energy and Power
Rules for dimensioning, disconnecting and protecting the neutral conductor
Dimensioning of neutral conductor Smaller than the cross-sectional area of the phase conductors… Equal to the cross-sectional area of the phase conductors Greater than or equal… Neutral conductor disconnection TN-C… Read more
Apr 19, 2017 | By Edvard
Energy and Power
Thumb rules for surge arrester installation in different earthing systems
A variety of documents deal with the subject of surge arrester installation: for example in France, standard NF C 15-531 focuses on the installation rules of LV surge arresters, and… Read more
Apr 17, 2017 | By Edvard
