Maintenance
What to do if transformer has an excessive moisture content
The term “moisture” in the transformer industry is commonly used to indicate water which is absorbed in the paper or dissolved in the oil. Occasionally, the terms “water” or “water content” are used as an alternative way to describe the… Read more
Apr 24, 2015 | By Edvard Csanyi
Testing and Commissioning
What to check when commissioning variable speed drives
The main purpose of commissioning VSDs is to ensure that: The AC converter and motor have been correctly installed and meet the wiring and safety standards such as IEC 60364 or Australian standard AS 3000. The power and motor cables… Read more
Apr 22, 2015 | By Edvard Csanyi
Energy and Power
4 power transformer protection devices explained in details
The power transformer protection is realized with two different kinds of devices, namely the devices that are measuring the electrical quantities affecting the transformer through instrument transformers and the devices that are indicating the status of the physical quantities at… Read more
Apr 20, 2015 | By Edvard Csanyi
Energy and Power
Detailed Overview of Power System Disturbances (Causes and Impacts)
To make the study of Power Quality problems useful, the various types of disturbances need to be classified by magnitude and duration. This is especially important for manufacturers and users of equipment that may be at risk. Manufacturers need to know what… Read more
Apr 17, 2015 | By Edvard Csanyi
Power Substation
Basic Stand-Alone Application of Reclosers
Reclosers are self-contained fault interrupting and reclosing devices, specifically designed for overcurrent protection in secondary distribution systems. Reclosers are situated in selected locations within the overhead distribution network. With the correct protection setting and MV fuse selection coordination, concerning the… Read more
Apr 15, 2015 | By Edvard Csanyi
Power Substation
Configurations and characteristics of distribution substations
Distribution substations come in many sizes and configurations. A small rural substation may have a nominal rating of 5 MVA while an urban station may be over 200 MVA. Figures 1 through 3 show examples of small, medium, and large… Read more
Apr 13, 2015 | By Edvard Csanyi
Electrical Lectures
Back To School – Let’s Calculate Current I3
Referring to the following circuit, calculate direct current I3: Using Kirchhoff’s laws; Using nodal analysis; Applying Thévenin’s theorem at nodes A and B. – KCL stands for Kirchhoff’s Current Law – KVL stands for Kirchhoff’s Voltage Law The following equation… Read more
Apr 10, 2015 | By Edvard Csanyi
Transformers
Network distribution transformers serving grid and spot networks
Network transformers, the distribution transformers that serve grid and spot networks, are large three-phase units. Network units are normally vault-types or subway types, which are defined as (ANSI C57.12.40-1982): Vault-type transformers // Suitable for occasional submerged operation Subway-type transformers // Suitable for… Read more
Apr 08, 2015 | By Edvard Csanyi
Power Substation
Important primary distribution (radial and loop) system considerations
The primary distribution system is that part of the electric distribution system between the distribution substation and distribution transformers. It is made up of circuits called primary feeders or distribution feeders. These feeders include the primary feeder main or main… Read more
Apr 06, 2015 | By Edvard Csanyi
Energy Efficiency
3 Lighting Essentials You Can’t Deny
Lighting systems in industrial facilities can represent an attractive savings opportunity, especially if lighting systems have not been upgraded or maintained in the past five years. The most cost-effective approach for lighting energy savings is to address the following three issues, in… Read more
Apr 03, 2015 | By Edvard Csanyi
Energy and Power
Good voltage regulation and justified power factor correction
Power factor correction and voltage regulation are closely related. In many cases, the desired voltage regulation is costly to obtain. Larger or paralleled conductors to reduce voltage drop under load are, in many cases, the proper solution. However, power factor… Read more
Apr 01, 2015 | By Edvard Csanyi
Cables
General guidelines for online partial discharge testing of power cables
Online PD testing is becoming the topic of interest for power cable owners to ensure the safe and continuous operation of power cables. Partial discharge is a localised discharge in the insulation medium due to high voltage stress that does… Read more
Mar 30, 2015 | By Ammar Anwar KHAN
Energy and Power
Six energy efficiency improvement opportunities in fan systems
Efficiencies of fan systems vary considerably across impeller types. The average energy saving potential in these systems in the U.S. manufacturing industry is estimated at 6%. For optimal savings and performance, it is recommended that a systems approach is used…. Read more
Mar 27, 2015 | By Edvard Csanyi
Maintenance
Maintenance of transformer load tap changers (LTC)
LTC maintenance is the basis for the regulating transformer’s high level of reliability. The background for maintenance recommendations is as follows: Oil: For LTCs where oil is used for arc-quenching, the arcing at the arcing switch or arcing tap switch… Read more
Mar 25, 2015 | By Edvard Csanyi
Energy and Power
Many engineers advocate the use of multiple-transfer switches
Automatic transfer switches are primarily used for emergency and standby power generation systems. These transfer switches may incorporate overcurrent protection and are designed and applied in accordance with the NEC, Articles 230, 517, 700, 701,702 and 710, and other applicable… Read more
Mar 23, 2015 | By Edvard Csanyi
