Twelve 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 of these leakage currents may cause highly sensitive residual protection… Read more
Jun 02, 2017 | By Edvard Csanyi
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 comparing different motors because the selected motor affects the size… Read more
May 24, 2017 | By Edvard Csanyi
4 medium voltage switching equipment for primary substation installations
This technical article covers the medium voltage switching equipment intended mainly for primary substation installations. The target is to give some basic knowledge and difference between four main piece of MV switching equipment, especially in the view of distribution automation… Read more
May 22, 2017 | By Edvard Csanyi
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 facilities at the central site. Basic troubleshooting of the various… Read more
May 19, 2017 | By Edvard Csanyi
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 of, for example, 300 kvar consists of six power capacitors,… Read more
May 17, 2017 | By Edvard Csanyi
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 which is useful when the sum of the currents flowing… Read more
May 12, 2017 | By Edvard Csanyi
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 pointers on how to recognize problems with harmonics in power… Read more
May 10, 2017 | By Edvard Csanyi
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 requires that the individual ground electrodes be disconnected from the… Read more
May 03, 2017 | By Edvard Csanyi
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 high, can cause the fuses to age or blow) and Stress… Read more
May 01, 2017 | By Edvard Csanyi
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 terms of damage as well as in terms of operating… Read more
Apr 28, 2017 | By Edvard Csanyi
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 for production sets whereas Diesel engines can be used for… Read more
Apr 26, 2017 | By Edvard Csanyi
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 different calculations. So, let’s list these calculations and start with… Read more
Apr 21, 2017 | By Edvard Csanyi
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 system TT or TN-S system IT system Important recommendations #1… Read more
Apr 19, 2017 | By Edvard Csanyi
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 standard NF C 15-100 covers all the LV electrical installations…. Read more
Apr 17, 2017 | By Edvard Csanyi
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 protection located upstream of each MV/LV power supply transformer. The… Read more
Apr 14, 2017 | By Edvard Csanyi