Classification of Transformer losses A transformer is a static device, hence mechanical losses (like windage or friction losses) are absent in it. There are mainly two types of losses in the transformer. They are 1. Core losses or Iron losses Hysteresis loss Eddy current loss 2. Copper losses Apart from these two types, there are … Read more
In this article, we will learn about Squirrel cage and slip ring induction motors. These motors are having the difference in rotor construction. Squirrel cage Induction Motor In Squirrel cage induction motors the rotor is simplest and most rugged in construction. Cylindrical laminated core rotor with heavy bars of copper or Aluminum is used for conductors. … Read more
Introduction Core Balance Current Transformer or CBCT is a ring-type current transformer through the center of which a three core cable or three single core cables (forms the primary winding) of three phase system passes. This type of current transformer is normally used for earth fault protection for low and medium voltage system. A typical … Read more
Voltmeters and Ammeters are used to measure the voltage and current in the circuits. Using instrument transformers, ranges of these devices to measure can be increased. A current transformer is basically a step-down transformer; hence it steps down the current. When used in conjunction with the low range ammeter, a current transformer (CT) increases the range … Read more
Insulation materials used in transformers and motors are classified based on the temperature withstand capability. Some of the insulation classes used in transformers and induction motors are: Class Y, Class A, Class E, Class B, Class F, Class H and Class C. Class Y Maximum hot spot temperature for this type of insulator is 90°C. … Read more
When a transformer is energized after a short interruption, the transformer may draw high inrush currents from the system due to core magnetization being out of synch with the voltage. The inrush currents will be as high as short-circuit currents in the transformer (almost 20 to 40 times the rated normal full load current of … Read more
DC machine whether it is motor or generator will have four essential parts. They are Field System Armature Commutator Brush and Brush gear 1. Field System The objective of field system in DC machine is to provide uniform magnetic field, within which armature rotates. For small rating motors permanent magnets are used and for large … Read more
AC power has become popular and advantageous because of easy generation, transmission with fewer losses to long distances due to stepping up voltage and stepping down the voltage to the desired level. In Industries 70% of the motors and drives used are Induction motors, hence ac motors in general means induction motors. Induction motors were … Read more
Traction is defined as ‘the act of drawing or pulling especially by a motive force‘ (drawing of carriage by horse constitute traction). In mechanical terms, it is defined as the ‘adhesive friction between the wheel and the surface on which it moves‘ (between a car tire and road). Traction system can be broadly classified as … Read more
Braking in DC motor is employed to make the dc motor to halt from operating condition by applying a brake. It is to be considered that significant difference exists between the words ‘braking’ and ‘breaking’, should not get confused. In dc motors we apply the brake to make the dc motor halt. Different braking methods … Read more
