Cables
Sizing calculations for 20/3.3 kV, 12.5 MVA transformer feeder cable
Typical calculations for a 20kV transformer feeder cable are presented below. After correct cable voltage classification the following considerations apply: Current carrying capacity Short circuit rating Voltage drop Earth loop impedance Consider a 20/3.3 kV, 12.5 MVA transformer to be… Read more
May 08, 2017 | By Edvard Csanyi
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 terms of damage as well as in terms of operating… Read more
Apr 28, 2017 | By Edvard Csanyi
Energy and Power
Six core activities in the commissioning of the earthing system
Commissioning of new earthing system is essential as a validation step for the design and installation process and for the design inputs. In most cases commissioning should measure the outputs of the earthing system in terms of produced voltages and… Read more
Apr 02, 2016 | By Edvard Csanyi
Cables
Recommended Practice For Cableways Selection and Installation
The term cableways refers to conductors and/or cables together with the means of support and protection, etc. for example cable trays, ladders, ducts, trenches, and so on… are all cableways. This technical article covers the following topics: Selection of materials… Read more
Mar 14, 2016 | By Edvard Csanyi
Energy and Power
LV Surge Arresters In Action Against Lightning
The site consists of offices (computer hardware, lighting and heating unit), a security post (fire alarm, burglar alarm, access control, video surveillance) and three buildings for the manufacturing process on 10 hectares in the Avignon region of France (probability of… Read more
Dec 29, 2015 | By Edvard Csanyi
Medium Voltage
Medium Voltage Earthing Systems – Arrangements and Comparison
First, let’s define the different medium voltage earthing systems and then compare the advantages and disadvantages of each one. Earthing systems in medium voltage can be differentiated according to the neutral point connection method. The various earthing systems in medium… Read more
Jul 03, 2015 | By Edvard Csanyi
Energy and Power
Danger And Control Of Static Electricity Buildup
It is necessary to study the static buildup potential of any workplace and institute protective measures to control such buildup. The following are the dangers posed by static electricity: Ignition causing fire or explosion Damage to sensitive electronic components Electric… Read more
Dec 12, 2014 | By Edvard Csanyi
Energy and Power
What Is Earth And Why And How Do We Connect To It?
The thin layer of material which covers our planet – rock, clay, chalk or whatever – is what we in the world of electricity refer to as earth. So, why do we need to connect anything to it? After all,… Read more
Oct 06, 2014 | By Edvard Csanyi
Energy and Power
Main short circuit faults occurring in networks and machines
Short-circuits can be defined according to three main characteristics: They may be mechanical: breakdown of conductors or accidental electrical connection between two conductors via a foreign body such as a tool or animal; They may be electrical: following the degradation of… Read more
May 30, 2014 | By Edvard Csanyi
Energy and Power
An Overview Of Grounding System (Ungrounded)
Ungrounded system Derivation of current expression in ungrounded system Advantages & disadvantages of ungrounded system Concept of effective and non-effective grounding Coefficient of earthing and earth fault factor Before 1950 power system were often without neutral grounding. Such system had… Read more
Oct 11, 2013 | By Asif Eqbal
Energy and Power
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 be generally divided into three main categories: Insulated earthing, Solid… Read more
Sep 16, 2013 | By Edvard Csanyi
Electrical Lectures
Electrical Thumb Rules You MUST Follow (3)
Continued from second part: Electrical Thumb Rules You MUST Follow (Part 2) For Motor Size of Capacitor = 1/3 Hp of Motor ( 0.12x KW of Motor) For Transformer < 315 KVA 5% of KVA Rating 315 KVA to 1000… Read more
Sep 02, 2013 | By Jignesh Parmar
Energy and Power
How to Determine Correct Number of Earthing Electrodes (Strips, Plates and Pipes) – part 2
Continued from first part: How to Determine Correct Number of Earthing Electrodes (Strips, Plates and Pipes) – part 1 The Earth Resistance of Single Plate electrode is calculated as per IS 3040: R=ρ/A√(3.14/A) Where: ρ = Resistivity of Soil (Ω… Read more
May 13, 2013 | By Jignesh Parmar
Electrical Lectures
How to Determine Correct Number of Earthing Electrodes (Strips, Plates and Pipes) – part 1
Earthing Resistance and the number of earthing electrodes are both dependent on the resistivity of the soil as well as the amount of time it takes for fault current to pass through (one second or three seconds). The number of… Read more
Apr 05, 2013 | By Jignesh Parmar
Energy and Power
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 difference between Grounding and Earthing. Earthing and Grounding are actually… Read more
Sep 27, 2012 | By Jignesh Parmar
