Energy and Power
What Is The Basic Insulation Level (BIL)
Insulation levels are designed to withstand surge voltages, rather than only normal operating voltages. Since the transmission & distribution lines and substation equipment are protected by surge arresters draining the surges rapidly before the insulation is damaged, the arrester must… Read more
Dec 03, 2012 | By Edvard Csanyi
Transformers
Right Choice of Dry Type or Liquid-Filled Transformer
1. Two Types of Transformers 2. Cooling and insulating system 3. Losses 4. Operating Life of Transformer 5. Maintainability 6. Repairability 7. Core/Coil Reclamation and Recycling 8. Operating Sound Level and Noise Pollution 9. Footprint 0. Conclusion Information on the… Read more
Sep 29, 2012 | By Edvard Csanyi
Electric Motor
Basics of 3-phase Induction Motor (part 2)
Continued from first part – Basics of 3-phase Induction Motor (part 1) For the purpose of standardization, the preferred rated voltages of three phase induction motor shall be in accordance with IS 12360: 1988. The voltages for three phases, 50… Read more
Aug 02, 2012 | By Asif Eqbal
Electrical Lectures
Fundamental Concepts of Insulation Testing
Probably 80% of all testing performed in electrical power systems is related to the verification of insulation quality. This technical article briefly describes the fundamental concepts of insulation testing including – insulation behavior, types of tests, and some test procedures…. Read more
Jul 07, 2012 | By Edvard Csanyi
Transformers
Meggering (insulation resistance testing) of dry-type power transformer
The insulation resistance test (meggering) is of value for future comparison and also for determining if the transformer is to be subjected to the applied voltage test.The winding insulation resistance test is a DC high voltage test used to determine… Read more
Jun 27, 2012 | By Edvard Csanyi
Electric Motor
Measurement of insulation resistance (IR) – Part 2
This article goes into details of insulation resistance values measured by Megger tester on many different kinds of equipment, such as switchgear, electrical wires & cables, electric motors, transmission & distribution lines, and other power system equipment. An insulation tester… Read more
Apr 29, 2012 | By Jignesh Parmar
Energy and Power
Inspection of electrical installations in home (2)
Every installation deteriorates with use and age. Therefore, one must ensure that the safety of users is not put at risk and that the installation remains in a safe and serviceable condition. Continued from part I – Inspection of electrical… Read more
Mar 26, 2012 | By Edvard Csanyi
Energy and Power
Megger Insulation Resistance Test
As you know good insulation has high resistance and poor insulation relatively low resistance. The actual resistance values can be higher or lower, depending upon such factors as the temperature or moisture content of the insulation (resistance decreases in temperature… Read more
Mar 13, 2012 | By Edvard Csanyi
Energy and Power
What is HIPOT Testing (Dielectric Strength Test)?
Hipot Test is short name of high potential (high voltage) Test and it is also known as Dielectric Withstand Test. A hipot test checks for “good isolation”. Hipot test makes surety of no current will flow from one point to… Read more
Dec 22, 2011 | By Jignesh Parmar
Cables
Partial Discharge Testing On Power Cable Systems
Partial discharge measurement is an important method of assessing the quality of the insulation of power cable systems, particularly for extruded insulation materials. This article considers partial discharge from two points of view: the measurement of all partial discharges occurring… Read more
Nov 18, 2011 | By Edvard Csanyi
Cables
How to locate underground faults on cable?
A common approach to test cable and determine insulation integrity is to use a Hi-pot test. In a hi-pot test, a DC voltage is applied for 5 to 15 min. IEEE-400 specifies that the hi-pot voltage for a 15-kV class… Read more
Oct 04, 2011 | By Edvard Csanyi
Power Substation
Complete overview of lightning arresters (part 2)
Continued from article Complete overview of lightning arresters (part 1) Surge arresters are devices that help prevent damage to apparatus due to high voltages. The arrester provides a low-impedance path to ground for the current from a lightning strike or… Read more
Sep 29, 2011 | By Jignesh Parmar
Transformers
Diagnosing Transformer Winding Insulation (video)
This video tutorial shows the progression of power factor or dissipation factor over frequency. Furthermore, measuring transformer winding insulation, including the connection of measuring leads, is explained. Reasons why recording frequency responses is important for a correct diagnosis of a… Read more
Sep 25, 2011 | By Edvard Csanyi
Energy and Power
Moisture Effect On Insulation Of Generator
Moisture, which can enter the insulation of a generator or motor winding from damp air or which can enter the winding of a transformer from wet oil, will make a surprisingly large difference in the insulation resistance. This is clearly… Read more
May 13, 2011 | By Edvard Csanyi
Low Voltage
Maintenance Of Molded Case Circuit Breakers (MCCB)
The maintenance of circuit breakers deserves special consideration because of their importance for routine switching and for protection of other equipment. Electric transmission system breakups and equipment destruction can occur if a circuit breaker fails to operate because of a… Read more
Jan 01, 2011 | By Edvard Csanyi
