AC Motor Fundamentals: You Must Know

AC Motors: AC motors are fascinating devices that convert electrical energy into mechanical motion using alternating current (AC). 

They have two main parts: a stationary stator and a rotating rotor. When AC power is supplied, it creates a magnetic field in the stator that interacts with the magnetic field of the rotor, causing it to turn and drive mechanical systems.

Synchronous and Asynchronous Motors Details

Each Synchronous and Asynchronous Motor type has its own strengths and suitable applications depending on the requirements.

Synchronous Motor

Definition of Synchronous Motor: A synchronous motor is an AC motor that runs at a speed directly proportional to the frequency of the supply current.

Protection Against Direct or Indirect Contact Without Automatic Disconnection System

What is Safety Extra-Low Voltage (SEVL)?

Safety by extra low voltage SELV is used in situations where the operation of electrical equipment presents a serious hazard, like swimming pools, amusement parks, etc. The impulse withstand level of insulation between the primary and secondary winding is very high. The secondary voltage never exceeds 50 V rms.

Three conditions of exploitation must be respected in order to provide satisfactory protection against indirect contact:

Relays Use in Electrical Substations and Their Functions

Relays play a crucial role in electrical substations by monitoring various parameters and controlling the operation of equipment. Here are some common relays used in electrical substations and their functions:

What Types of Relays Are Used in Electrical Substations?

Overcurrent Relay: Overcurrent relays are used to protect electrical equipment from excessive currents. They sense the current flowing through a circuit and, if it exceeds a predetermined threshold, the relay trips and sends a signal to a circuit breaker to interrupt the current flow, thereby protecting the equipment from damage. 

What is Over Current Relay and How Does It Work?

The overcurrent relay is defined as the relay, which operates only when the value of the current is greater than the relay setting time.

An overcurrent relay is a protective device used in electrical systems to detect and respond to excessive current flowing through a circuit. It is designed to protect the equipment and wiring from damage caused by overloads or short circuits. The relay operates by sensing the current in the circuit and activating a trip mechanism when the current exceeds a predetermined threshold.

How Does an Overcurrent Relay Work?

Conductor Stranding Perspective of Power Cable Construction

Conductor Stranding Perspective of Power Cable Construction

Conductor stranding is a major aspect of cable construction that came long experience in different circumstances. 

The problem with larger sizes of solid conductors is too rigid for installation in curvy areas, jointing, and termination work. The solution to these difficulties comes from conductor stranding. 

The procedure of stranding is used depending on the metal temper and types. In general Copper conductor and Aluminum, copper conductors and aluminum conductors are used for power cable construction. Normally Aluminum is softer than Copper, so the use limit is higher than that of copper.

Fig: Conductor strands arrangement system