Electrical Components and Motors: Types, Functions, and Safety

Posted on Jan 12, 2025 in Electronics

Electrical Components: Types and Functions

Triggers

  • Magnetic Trigger: Acts opposite to short-circuit currents with very fast cutting.
  • Thermal Trigger: Acts in case of overload, cutting slowly.

Terminals

Buttonhole, fork, pin, sheet, and splice sleeves.

Types of Busbars

Vertical side, deep vertical, horizontal and vertical, horizontal.

Protection Ratings

  • IP: Protection against solid objects or liquids.
  • IK: Protection against mechanical shock.

Types of Files

Flat, half-round, triangular, square, round.

Voltage and Intensity Measurement

Explains why voltages are measured in parallel and intensities in series.

Fuses

Monopolar, bipolar, tripolar, tripolar with switchgear. There are cylindrical, blade, and DIAZED types.

Curves

The type of curve determines the operation of the circuit breaker, cutting time, and trigger that acts based on the intensity value.

Types of Curves

  • Curve B: Protects circuits where low-intensity short circuits are expected. Used in fully resistive circuits such as heating and lighting.
  • Curve C: Protects circuits in general use facilities with the possibility of connecting small motors.
  • Curve D: Suitable for installations where devices with high inrush currents are used, such as large motors and capacitive loads.
  • Curve ICP: Used as a power control switch.

Electric Motors

Internal Parts of an Electric Motor

  • Rotor: Rotating part of the machine.
  • Stator: Fixed part of the machine.

Cross-References

Numbers that indicate the location of a component on a sheet.

External Parts of an Electric Motor

  • Terminal Box: Allows connection to the power system.
  • Nameplate: Contains the most important data of the motor.
  • Belt: Transmits the rotary motion of the motor.
  • Carcass: Covers the entire motor.
  • Fan Cover: Covers the ventilation system of the motor.
  • Mounting Base: Part of the carcass that allows the motor to be fixed to a bench.

Types of Three-Phase Induction Motors

  • Squirrel Cage
  • Wound Rotor

Squirrel Cage Motor Connections

Early: U1 V1 W1
Modern: U V W
End: W2 U2 V2
Modern: X Y Z

Connections

  • Triangle Connection: Used for low line voltage.
  • Star Connection: The bottom ends are connected together, and the top ends are connected to the line.

Reversing the Direction of a Three-Phase Motor

Achieved by swapping any two phases.

Phase Loss in a Three-Phase Motor

If one of the three phases is lost, overcurrent occurs, potentially damaging the internal windings.

Torque

The force that a motor can exert in each turn.

Starting an Induction Motor

When an induction motor starts, the current rises momentarily and then decreases. This can be dangerous for the motor. A star-delta starter can be used to avoid this. In the first step, the motor runs with the terminals connected in star, consuming about three times less than the nominal current.

Wound Rotor Induction Motors

Used for very specific applications that require high starting torque.

Differential Switch

A device that protects the installation against insulation faults and people against indirect contacts.

Selectivity

Can be based on time and intensity.