Electrical Lectures
2 Most Common Contributing Factors In Motor Insulation Failure
The most frequent failure in electrical equipment is the degradation and breakdown (flashover) of the insulation. Electrical insulation can be liquid or solid, organic or inorganic. Organic insulation material consists of: enamels, varnishes, resins, or polymers that are applied to the steel surface to provide… Read more
Jun 25, 2014 | By Edvard Csanyi
Energy and Power
Differences between disconnectors, load switches, switch disconnectors and circuit breakers
Various types of devices are available for carrying out the switching and protection tasks listed under a title that are specially designed to fulfill the respective requirements. The various parts of IEC 60947 (Low voltage switchgear and controlgear) specify the… Read more
Jun 20, 2014 | By Edvard Csanyi
Energy and Power
6 Factors Influencing Requirements for a Good Grounding System
In an industrial plant or other facility that requires a grounding system, one or more of the following must be carefully considered (refer to Figure 1 below): Limiting to definite values the voltage to earth of the entire electrical system…. Read more
Jun 06, 2014 | By Edvard Csanyi
Energy and Power
It can happen to experienced engineers too. Stay carefull.
The effect of electricity on the body depends on the amount of current and the length of time the body is exposed to it. The higher the current, the less time a human can survive the exposure. The path of… Read more
Jun 02, 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
Generating Electricity with Combustion Turbines
There are two basic types of combustion turbines (CTs) other than the microturbines: The heavy frame industrial turbines and The aeroderivative turbines. The heavy frame systems are derived from similar models that were steam turbine designs. As can be identified… Read more
May 28, 2014 | By Edvard Csanyi
Energy and Power
Arriving at the scene of a pole fire. What to do?
Utility pole fires are common and should be treated with great respect by firefighters. Pole fires are normally caused by the failure of insulators, switches, catastrophic failure of transformers or oil-filled switching equipment. Some poles used in the utility industry… Read more
May 21, 2014 | By Edvard Csanyi
Energy and Power
Case study – Improper grounding practice of computers in buildings
In a large office complex, computer errors including system crashes/reboots were happening during thunderstorms. The grounding of computer system had been carried out according to the recommendations of manufacturers. The grounding leads were insulated and terminated to an isolated grounding bus. This bus… Read more
May 14, 2014 | By Edvard Csanyi
Energy and Power
Earthing (grounding) transformer – Voltages during a ground fault
Earthing Transformer or grounding transformer is the neutral grounding transformer – star connected on the primary and has an open delta on secondary. Open Delta has two terminals. A resistor is connected across these two terminals. Whenever a fault occurs, voltage… Read more
May 05, 2014 | By Asif Eqbal
Energy and Power
What affects the operating temperature within LV switchgear
BS EN 60439 states a maximum indoor ambient temperature of 40ºC, a maximum daily average of 35ºC and a minimum ambient of -5ºC. As a general guidance rule, the temperature within the low voltage switchgear should not exceed 50/55ºC. If… Read more
Apr 30, 2014 | By Edvard Csanyi
Energy and Power
8 steps to begin basic circuit design
What do we need to know? Clearly, plunging into calculations of cable size is of little value unless the type of cable and its method of installation is known. This, in turn, will depend on the installation’s environment. At the… Read more
Apr 11, 2014 | By Edvard Csanyi
Energy and Power
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 the fault path, the maximum values of Zs given in… Read more
Apr 09, 2014 | By Edvard Csanyi
Energy and Power
Erection of earthing arrangements (TNC, TN-S, TNC-S, TT)
The earthing arrangements (TNC, TN-S, TNC-S, TT) of low voltage networks is largely determined by the Low Voltage Supplies. However, if the incoming supplies are at 11kV and the transformers are in the ownership of the user, the LV supplies… Read more
Apr 07, 2014 | By Edvard Csanyi
Energy and Power
Electromagnetic stresses on a busbar system and methods of reducing
When a conductor carries a current it creates a magnetic field which interacts with any other magnetic field present to produce a force. When the currents flowing in two adjacent conductors are in the same direction the force is one… Read more
Apr 02, 2014 | By Edvard Csanyi
Energy and Power
Electrical Design Project of a Three Bed Room House (Part 2)
Continued from 1st part: Electrical Design Project of a Three Bed Room House (Part 1) All new domestic dwellings, including conversions, must either have: A fire detection and fire alarm system in accordance with the relevant recommendations of British Standard… Read more
Mar 31, 2014 | By Sufi Shah Hamid Jalali
