Cables
Cable spacing as a means of noise mitigation
In situations where there are a large number of cables varying in voltage and current levels, the IEEE 518-1982 standard has developed a useful set of tables indicating separation distances… Read more
Jul 11, 2014 | By Edvard
Energy and Power
Harmonic distortion and high frequency applications
The presence of harmonic frequencies in addition to the fundamental 50Hz, bring about distortion of the fundamental sine wave. Considerable problems may arise dependant upon the level of this distortion…. Read more
Jul 07, 2014 | By Edvard
Energy and Power
How the Weather Affects Conductors
Notice how a conductor is strung between poles. It is not pulled tight; it sags. In hot weather it sags even more than in cold weather. Consider the analogy of… Read more
Jul 04, 2014 | By Edvard
Cables
An example how to calculate voltage drop and size of electrical cable
Electrical load of 80KW, distance between source and load is 200 meters, system voltage 415V three phase, power factor is 0.8, permissible voltage drop is 5%, demand factor is 1…. Read more
Jun 30, 2014 | By jiguparmar
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… Read more
Jun 25, 2014 | By Edvard
Energy and Power
Differences between disconnectors, load switches, switch disconnectors and circuit breakers
Various types of device are available for carrying out the switching and protection tasks listed under title that are specially designed to fulfill the respective requirements. The various parts of… Read more
Jun 20, 2014 | By Edvard
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… Read more
Jun 06, 2014 | By Edvard
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… Read more
Jun 02, 2014 | By Edvard
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… Read more
May 30, 2014 | By Edvard
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… Read more
May 28, 2014 | By Edvard
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… Read more
May 21, 2014 | By Edvard
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… Read more
May 14, 2014 | By Edvard
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… 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… Read more
Apr 30, 2014 | By Edvard
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,… Read more
Apr 11, 2014 | By Edvard
