Lighting
Difference Between Diffuse and Directed Light
Having dealt with light quantity, conside-ration must be given to the quality of light, the difference between diffuse light and directed light being one of the most important aspects. We are familiar with these different forms of light through our… Read more
Oct 13, 2012 | By Edvard Csanyi
Energy and Power
NEC Requirements for Emergency Systems
Emergency systems are generally installed in buildings that are or can be occupied by 1000 or more persons or are more than 75 ft high. These are buildings where artificial illumination is required for safe exiting and for panic control…. Read more
Oct 12, 2012 | By Edvard Csanyi
Power Substation
Switching Impulse Test of the Transformer
The switching impulse test is applied to confirm the withstand of the transformer’s insulation against excessive voltages occurring during switching. During the switching impulse voltage test, the insulation between windings and between winding and earth and withstand between different terminals… Read more
Oct 11, 2012 | By Edvard Csanyi
Energy and Power
Safety Clearance Recommendations for Electrical Panel
Working Space around Indoor Panel/Circuit Board (NES 312.2) Clearance around an Indoor electrical panel (NEC 110.26) Clearance for Conductor Entering in Panel (NES 408.5) Clearance between Bare Metal Busbar in Panel (NES 408.5) Clearance of Outdoor electrical panel to Fence/Wall… Read more
Oct 10, 2012 | By Jignesh Parmar
Energy and Power
Fire-Fighting Precautions in Power Substation
The layout of the plant and the design of the building play a major part in reducing the spread of fire and the effect of explosions. For example, equipment and buildings should be arranged to have vents which rupture rather… Read more
Oct 09, 2012 | By Edvard Csanyi
Protection
Overcurrent protection of transformer (NEC 450.3)
The overcurrent protection required for transformers is consider for Protection of Transformer only. Such overcurrent protection will not necessarily protect the primary or secondary conductors or equipment connected on the secondary side of the transformer. Introduction Overcurrent protection of transformers… Read more
Oct 08, 2012 | By Jignesh Parmar
Energy and Power
Disturbances In LV Networks Due To Surges
There are two types of surge: those generated by a lightning impact and those resulting from electrical switchgear switching operations. Surges resulting from lightning strokes (see figure below) can affect all electrical installations. Consequently, they are without doubt the main… Read more
Oct 06, 2012 | By Edvard Csanyi
Energy and Power
How to Protect Capacitor Banks?
Capacitor banks are used to compensate for reactive energy absorbed by electrical system loads, and sometimes to make up filters to reduce harmonic voltage. Their role is to improve the quality of the electrical system. They may be connected in… Read more
Oct 05, 2012 | By Edvard Csanyi
Industrial Automation
Basic steps in PLC programming for beginners
The first step in developing a control program is the definition of the control task. The control task specifies what needs to be done and is defined by those who are involved in the operation of the machine or process…. Read more
Oct 04, 2012 | By Edvard Csanyi
Transformers
Dry Transformer Percent Impedance Definition
The percent impedance is the percent voltage required to circulate rated current flow through one transformer winding when another winding is short-circuited at the rated voltage tap at rated frequency. %Z is related to the short circuit capacity of the transformer during short… Read more
Oct 03, 2012 | By Edvard Csanyi
Energy and Power
Definitions of Abnormal Voltage Conditions
A sag is a temporary reduction in the normal AC voltage. A momentary sag is a variation, which lasts for a period of 0.5 cycle to about 2 s usually the result of a short circuit somewhere in the power system. Instances… Read more
Oct 02, 2012 | By Edvard Csanyi
Power Substation
Designing of HV Power Substation and Layout
Introduction Earthing and Bonding Substation Earthing Calculation Methodology (Earthing Materials) Layout of Substation Different Layouts for Substations (single busbar, mesh, 1 1/2 cb) Principle of Substation Layouts (spatial separation, maintenance zones) Components of a Substation (cbs, cts, isolators, insulation, transformers etc.) Substations are the… Read more
Oct 01, 2012 | By sprabakar22
