Indepth Electrical engineering

Locked Rotor Current and Torque in Induction Motors What is Locked Rotor Current? Locked rotor current (LRC) is the maximum current drawn by an induction motor when its rotor is not rotating (locked condition) . At startup, since the motor speed is zero, the slip is 1 (100%), and the motor draws its highest current. This current is usually 3–8 times the full load current (FLC) . As the motor accelerates, the current gradually reduces until it stabilizes at the rated full load current. LRC depends on the motor design, type, and supply voltage (higher supply voltage → lower current for the same power). 👉 In other words, "locked rotor current" is the current drawn if the motor is energized but prevented from turning. Equivalent Circuit at Locked Rotor Condition At locked rotor, each stator phase behaves like a series R–L circuit . Resistance (R): Copper loss component. Inductance (L): Reactance due to leakage ...

For transmission of power at High voltage Transmission lines needed to be laid. For laying Transmission lines Transmission towers are most widely used in world. Transmission towers are used for following purposes:- 1.        To separate high voltage conductors from surroundings and from each other. 2.        To keep conductors at sufficient height for safe limits. An overhead transmission line usually consists of three conductors or bundles of conductors containing the three phases of the power system. The conductors are usually aluminum cable steel reinforced (ACSR), which are steel core (for strength) and aluminum wires (having low resistance) wrapped around the core. Tower designing is most important part as towers has to sustain natural calamities.  There are following parts in Transmission towers:- 1.        Tower top 2.        Cross a...

Cable Selection Guide: Voltage, Current Capacity, Insulation, and Installation Methods  Learn how to select the right electrical cables based on voltage level, current carrying capacity, insulation type, installation method, number of cores, and environmental conditions. Introduction Selecting the right power cable is crucial in electrical systems to ensure safety, efficiency, and long-term reliability. Cable selection depends on various factors such as voltage level, current carrying capacity (ampacity), insulation type, number of cores, installation method, and environmental conditions . Using the wrong cable can lead to overheating, excessive voltage drop, or even failure of the electrical system. 1. Cable Selection According to Voltage Level Cables are categorized based on their nominal voltage ratings. The classification is as follows: Low Tension (LT) Cables : Up to 1000 V High Tension (HT) Cables : Up to 11 kV Super Tension Cables : From 22 kV to 33 kV Ex...