How to Protect Capacitor Banks?
Capacitor banks are used to compensate for reactive energy absorbed by electrical system loads, and sometimes to make up filters to reduce harmonic voltage. Their role is to improve the… Read more
Oct 05, 2012 | By Edvard Csanyi
Definitions of Abnormal Voltage Conditions
A sag is a temporary reduction in the normal AC voltage. A momentary sag is a variation, which lasts for a period of 0.5 cycle to about 2 s usually the… Read more
Oct 02, 2012 | By Edvard Csanyi
What is the difference between Bonding, Grounding and Earthing?
One of the most misunderstood and confused concept is difference between Bonding, Grounding and Earthing. Bonding is more clear word compare to Grounding and Earthing, but there is a micro… Read more
Sep 27, 2012 | By jiguparmar
Inspection of Ground-Fault Protection Systems
This type of protection is defined by the NEC (National Electrical Code) to ensure protection against fire on electrical power installations. To ensure protection against fire: The NEC defines the… Read more
Sep 25, 2012 | By Edvard Csanyi
Surge Protection of Electronic Equipment
Generally, power circuits have components that have large thermal capacities, which make it impossible for them to attain very high temperatures quickly except during very large or long disturbances. This… Read more
Sep 22, 2012 | By Edvard Csanyi
Introduction to Static Protection Relays
The term ‘static’ implies that the relay has no moving parts. This is not strictly the case for a static relay, as the output contacts are still generally attracted armature… Read more
Sep 21, 2012 | By Edvard Csanyi
What is the purpose of equipotential bonding?
Equipotential bonding is essentially an electrical connection maintaining various exposed conductive parts and extraneous conductive parts at substantially the same potential. An earthed equipotential zone is one within which exposed… Read more
Sep 20, 2012 | By Edvard Csanyi
Functions Performed by Electrical Switchgear
National and international standards define the method for making electrical distribution circuits as well as the purpose and functions of switchgear. There are three main functions, namely: Circuit protection takes… Read more
Sep 14, 2012 | By Edvard Csanyi
Transformer differential protection (ANSI 87T)
Transformer differential protection protects against short-circuits between turns of a winding and between windings that correspond to phase-to-phase or three-phase type short-circuits. If there is no earthing connection at the… Read more
Sep 05, 2012 | By Edvard Csanyi
Motor protection depending on size and voltage level
Motor protections vary widely depending on the size of the motor and voltage level involved, thus only the more common ones are discussed in this technical article. Index Motor Instantaneous… Read more
Aug 30, 2012 | By Edvard Csanyi
High resistance grounding equipment in mining applications
High resistance grounding equipment or permanently installed electrical distribution systems used in mines should be selected and applied as recommended for process industries. When mobile equipment is connected to the distribution system… Read more
Aug 22, 2012 | By Edvard Csanyi
Protecting Oil Type Transformer with Buchholz Relay
Buchholz relay is a gas-actuated relay installed in oil immersed transformers for protection against all kinds of faults. Named afteri ts inventor mr. Max Buchholz (1875–1956) in 1921, relay is used… Read more
Aug 16, 2012 | By Edvard Csanyi
Delayed Auto-Reclosing On EHV Systems
On highly interconnected transmission systems, where the loss of a single line is unlikely to cause two sections of the system to drift apart significantly and lose synchronism, delayed auto-reclosing can be employed…. Read more
Aug 11, 2012 | By Edvard Csanyi
Sizing and protection of the neutral conductor (2)
Continued from the first part – Sizing and Protection of the Neutral Conductor (1) If the neutral conductor is correctly sized (including harmonics), no specific protection of the neutral conductor is… Read more
Jul 31, 2012 | By Edvard Csanyi
Overvoltages in the IT system
Electrical networks can be subject to overvoltages of varying origins. Some overvoltages, such as differential mode ones (between live conductors) affect all the earthing systems. This section is particularly concerned… Read more
Jul 26, 2012 | By Edvard Csanyi