Tricky but Easy Electrical Engineering!
As we know that the secondary voltages of a 3-phase transformer may undergo a phase shift of either +30° leading or -30° lagging or 0° i.e. no phase shift or 180° reversal with respective line or phase to neutral voltages. On the name plate of a three phase transformer, the vector group is written as … Read more
The main and basic difference between a Power transformer and a Distribution Transformer is that Power transformers are used in transmission network of higher voltages for step-up and step down application like 400 kV, 200 kV, 110 kV, 66 kV, 33kV and are generally rated above 200 MVA. Distribution transformers are used for lower voltage … Read more
The core type transformers have many advantages over shell type transformers as follows: The core is greater than shell but the circular coils that are used are easier to wind. Provide more mechanical strength especially when short circuit occurs. High space factor and reduced mean length of turns resulting in reduced copper losses. Longer mean … Read more
Power System nowadays is one of the most complex system. There are a number of generating stations that generate power equal to load at that particular time. However, if need arises, the system can generate more power. This ability of power system to generate power over and above the current demand is expressed as reserve … Read more
The basic principle for Breaker operation is to extinguish arc which form when the Breaker is opened. But it does not mean that arcing donot take place when the breaker is closed, rather it does. The time duration for which arcing take place when Breaker is closed is known as Pre-arcing Time which is typically … Read more
To understand this aspect making current and breaking current, first we should know what actually the making current and breaking current signifies in context with Circuit Breaker. Making Current of a Circuit Breaker is the peak value of maximum current loop during subtransient condition including DC component when Breaker closes. In the figure below, I1 … Read more
HRC stands for High Rupturing Capacity. HRC Fuse has high rupturing capacity. Because of its high current rupturing capacity, a special method for extinguishing arc is required in the design of HRC Fuse. Construction of HRC Fuse: HRC Fuse consists of heat resisting ceramic body having metal end caps on which silver current carrying element … Read more
Please have a look at the below figures of Squirrel Cage Induction and Wound Rotor / Slip Ring Induction Motor. The figure itself depicts many difference between the two types of motors. Don’t worry, difference between Squirrel Cage and Slip Ring type Induction Motor is tabulated after the figure. Squirrel Cage Induction Motor: Slip … Read more
As we know that Lightning is an electric discharge in the form of a spark or flash originating in a charged cloud. Lightning is a very long electrical spark, ‘very long meaning greater than about 1 kilometer. Most lightning is generated in thunderstorms and is characterized by a length of 5 to 10 km, at … Read more
It seems amazing that Insulation Resistance (IR) of a Cable is inversely proportional to the length of Cable. As per our general perception, the resistance is directly proportional to length of conductor but mind here that it is not the resistance of conductor rather it is the resistance of the Insulation provided around the conductor. … Read more