Which type of residual current device (RCD) to use and when?
We know how (very) important the total earth loop impedance Zs is in the reduction of shock risk. However, in TT systems where the mass of earth is part of… Read more
Apr 09, 2014 | By Edvard Csanyi
Erection of earthing arrangements (TNC, TN-S, TNC-S, TT)
The earthing of low voltage networks in the UK is largely determined by the Low Voltage Supplies. However, if the incoming supplies are at 11kV and the transformers are in… Read more
Apr 07, 2014 | By Edvard Csanyi
Practical calculations of lightning strikes frequency
We distinguish between the following frequencies of lightning strikes which can be relevant for a building or structure: ND – Frequency of direct lightning strikes to the building or structure;·… Read more
Nov 04, 2013 | By Edvard Csanyi
What’s Really Important When You’re Designing The Low Voltage Switchgear?
Here what’s important when you’re designing the low voltage switchgear: Device Application in the Supply Circuit Short-circuit strength Release (Trip Unit) Device Application in Supply Circuits (Coupling) Device Application in… Read more
Oct 07, 2013 | By Edvard Csanyi
Comparison Of Neutral Earthing Methods
Neutral earthing systems are very similar to circuit breakers in that they do nothing until something in the system goes wrong! There are several methods for system earthing which can… Read more
Sep 16, 2013 | By Edvard Csanyi
Lightning And Surge Protection For Cable Networks And Antennas For TV (Part 2)
Continued from part one: Lightning And Surge Protection For Cable Networks And Antennas For TV (Part 1) If an antenna is protected by isolated air-termination systems it means: – That… Read more
Sep 13, 2013 | By Edvard Csanyi
Lightning And Surge Protection For Cable Networks And Antennas For TV (Part 1)
IEC 60728-11 complies with the state of the art and offers easy, standardized and effective protective mechanisms against the effects of lightning strikes into antennas. Antennas installed according to this… Read more
Sep 09, 2013 | By Edvard Csanyi
National Fire Alarm Code Defined By NFPA 72
NFPA 72 is the National Fire Alarm Code. The importance of installing smoke and fire alarms in homes is supported by results from exhaustive investigations of home fires indicating that… Read more
Aug 16, 2013 | By Edvard Csanyi
Equipotential Bonding For Metal Installations
The electrical low voltage consumer’s installation requiring certain earthing resistances (disconnection conditions of the protective elements) and the foundation earth electrode providing good earthing resistances at cost-effective installation, the foundation… Read more
Jul 26, 2013 | By Edvard Csanyi
Surge protective categories defined by ANSI/IEEE C62.41
Three different surge protective classes or zones have been defined by ANSI/IEEE C62.41, Recommended Practice on Surge Voltages in Low Voltage Power Circuits. These classes are illustrated in the pictorial diagram… Read more
Jun 28, 2013 | By Edvard Csanyi
Overvoltages Caused by Lightning
Overvoltages of atmospheric origin arise from uncontrollable sources and their severity for the load depends on many parameters that are determined according to where the lightning strikes and the structure… Read more
Apr 26, 2013 | By Edvard Csanyi
An overview of GFCI – Ground-fault circuit interrupter
The NEC requires that Ground-Fault Circuit Interrupters (GFCIs) be installed in many different rooms and locations in both public and private buildings. They are now required in bathrooms, kitchens, appliance… Read more
Apr 10, 2013 | By Edvard Csanyi
Active fire protection measures in power substation
Active fire protection measures are automatic fire protection measures that warn occupants of the existence of fire, and extinguish or control the fire. These measures are designed to automatically extinguish… Read more
Apr 01, 2013 | By Edvard Csanyi
Lightning Protection System – Germany Regulations
The purpose of a lightning protection system is to protect buildings from direct lightning strikes and possible fire, or from the consequences of the load-independent active lightning current (non-igniting flash… Read more
Mar 22, 2013 | By Edvard Csanyi
Working principle of thermal motor protection relay
Thermal motor protection relays contain three bimetal strips together with a trip mechanism in a housing made of insulating material. The bimetal strips are heated by the motor current, causing… Read more
Mar 09, 2013 | By Edvard Csanyi