Cables
Practices for grounding and bonding of cable trays
Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system. There is no restriction as to where the cable tray system is installed. The metal in… Read more
Feb 26, 2014 | By Edvard Csanyi
Electric Motor
Inspection and test procedures for Rotating Machinery, Synchronous Motors and Generators
Visual and Mechanical Inspection Electrical Tests Test Values Visual and Mechanical Tests Electrical Tests Pictures: Electrical machine wired for electrical testing The Electrical Machines Laboratory TABLE 100.10 – Maximum Allowable Vibration Amplitude TABLE 100.12 – US Standard Fasteners Compare equipment… Read more
Feb 19, 2014 | By Edvard Csanyi
Transformers
How challenging can be transporting of a Large Power Transformer (LPT)
Transporting an Large power transformer (LPT) can be quite challenging. LPTs large dimensions and heavy weight pose unique requirements to ensure safe and efficient transportation. Current road, rail, and port conditions are such that transportation is taking more time and… Read more
Feb 14, 2014 | By Edvard Csanyi
Energy and Power
Effect of utility-induced surges in a steel mill with variable speed drives
A steel mill with variable speed drives (VSDs) had problems of frequent tripping of the VSDs with the indication overvoltage in AC line. Each tripping caused severe production disruption and resulted in considerable monetary loss due to lost production. Steady-state… Read more
Feb 12, 2014 | By Edvard Csanyi
Electrical Lectures
What is the short-circuit switching (making / breaking) capacity?
The switching capacity is the r.m.s value of a current at a given power factor cos φ as well as a given rated voltage at which a switchgear or a fuse can still shut-off under specified conditions in an operationally… Read more
Feb 10, 2014 | By Edvard Csanyi
Energy and Power
Electrical Preventive Maintenance of Air Circuit Breakers
Remove and clean interphase barriers. Clean all insulating materials with vacuum and/or clean lint free rags. If it is necessary to use cleaning solvents, use only solvents recommended by the manufacturer. Inspect for (early) signs of corona, tracking, arcing, or… Read more
Feb 07, 2014 | By Edvard Csanyi
Energy and Power
Purposes and Examples of Safety Interlocking Devices
Most switchboards and motor control centres are fitted with a variety of electrical and mechanical safety interlocking devices. Their purposes are to protect against for example: Withdrawing the switching device while it is carrying load or fault current. Prevent the switching… Read more
Feb 05, 2014 | By Edvard Csanyi
Energy and Power
Conceptual Model of Smart Grid Framework by IEC
From a communication point of view, each system plays the role of either supplier or consumer of information, or more typically both. In addition to this intersystem communication, these systems consist of subsystems with specific internal communications. The following paragraphs… Read more
Feb 03, 2014 | By Edvard Csanyi
Energy and Power
MV Circuit Breaker Or Vacuum Contactor? (2)
Continued from first part: MV Circuit Breaker Or Vacuum Contactor? (Part 1) When applied properly, both medium-voltage circuit breakers and medium-voltage fused contactors should provide decades of reliable service. Applied incorrectly, either can lead to major headaches. Characteristic Circuit Breaker Contactor… Read more
Jan 31, 2014 | By Mohan Krishnasamy
Energy and Power
MV Circuit Breaker Or Vacuum Contactor? (1)
To compare the application of medium-voltage circuit breakers and of fused contactors, we must understand the basic characteristics of each switching technology. Comparison presented here shows the major characteristics of medium-voltage circuit breakers and medium-voltage fused contactors that influence the… Read more
Jan 29, 2014 | By Mohan Krishnasamy
Power Substation
6 Simple Rules to Ensure Substation Safety
Another extremely important substation engineering aspect is associated with safety protection. It is fair to say that safety is always a No. 1 priority in substation design, operation and maintenance. Unlike the case where a higher reliability required a larger… Read more
Jan 27, 2014 | By Edvard Csanyi
Energy and Power
Dimensioning of Power Distribution Systems (2)
Continued from the first part: Dimensioning of Power Distribution Systems (1) Dimensioning of cable routes and devices follows the maximum load currents to be expected at this distribution level. As a rule: Ib max = ∑ installed capacity x simultaneity… Read more
Jan 24, 2014 | By Edvard Csanyi
Testing and Commissioning
Power Transformer Capacitance and Dissipation Factor Test
The capacitance and dissipation factor test is an AC low voltage maintenance test and is very similar to the power factor test. While the transformer preparation is identical to the power factor test procedure, there is no requiremnts to make… Read more
Jan 22, 2014 | By Edvard Csanyi
Energy and Power
Dimensioning of Power Distribution Systems (1)
When the basic supply concept for the electricity supply system has been established, it is necessary to dimension the electrical power system. Dimensioning means the sizing rating of all equipment and components to be used in the power system. In… Read more
Jan 20, 2014 | By Edvard Csanyi
Testing and Commissioning
How to perform a power transformer turns ratio test
Power transformer turns ratio test is an AC low voltage test which determines the ratio of the high voltage winding to all other windings at no-load. The turns ratio test is performed on all taps of every winding. The Transformer… Read more
Jan 17, 2014 | By Edvard Csanyi
