Electrical Wiring & 3-Phase Motor Control full course

Explore the three-phase rotor motor, including rotor, stator, frame, bearings, and copper bars forming an interior rotatory circuit with N and S poles, six outputs, 400 volts, and 50 hertz.

Identify the six output wires of a three-phase motor and map them to U1, U2, V1, V2, W1, W2, following IEC naming for terminals.

Explore star and delta connections for three-phase motors, linking U2, V2, W2 in star and L1-U1, L2-V1, L3-W1 in delta, noting delta's full power vs star's one-third output.

Operate a cam switch to start or stop a three-phase motor, wiring L1–L3 to L1–L3 and U–V–W to U1–V1–W1, then apply the star startup method to run the motor.

start a three-phase motor greater than four kilowatts in star, then switch to delta after reaching about 70% of the motor's main speed using a star-delta switch that automates connections.

Explore start and stop push buttons in wiring, including normally open and normally closed configurations. Learn about coil actuation, terminals, and IEC/NEMA symbols.

Learn how contactors start and control single and three phase motors using A1–A2 coils, copper contacts, and a magnetic core, with power and control contacts such as 13–14 and 21–22.

Use a control transformer to step 400 volts down to 110 volts for control circuits, with a fuse, earth connection, and a virtual null line for circuits such as contactors.

Relays operate on low currents and resemble contactors. A1/A2 poles energize to close contacts; SPST and SPDT types offer normally open or closed contacts and solid-state relays enable quieter switching.

Identify and understand four common electrical faults in three-phase motors—overcurrent, short circuit, loss of a phase, and earth fault—and learn basic protection strategies.

Explore the mcb circuit breaker and how magnetic and thermal elements protect motors from short circuits and overloads, with single-pole and three-pole configurations and IEC and NEMA symbols.

Understand overload relays, or bimetal relays, that protect motors from overloads through a brass-iron bimetal pair that trips contacts on temperature rise, with auxiliary contacts and control circuits.

Learn about MPCB motor protect circuit breakers for single-phase, three-phase, and dc motors, guarding against short circuits and overloads, with L and T terminals, modes, and auxiliary and fault contacts.

Learn how earth fault protection uses a core balance current transformer to detect leakage and imbalance, triggering the MCCB shunt trip to stop the motor.

Explore how power circuits transfer voltage from phase lines to a three-phase motor, and how the control circuit interacts with it in the common electrical panel.

Explore a DOL control circuit for a three-phase motor, wiring fuses to a contactor and overload relay, controlled by start and stop push buttons that energize A1 and de-energize A2.

Add overload protection to a DOL control circuit using a bimetal overload relay wired through terminals 95/96, with stop/start buttons and the contactor, plus auxiliary contacts 13/14.

Learn how to wire forward and reverse motors with two contactors, swap T terminals to reverse rotation, and use fuses and a control circuit to prevent short circuits.

Presents a forward/reverse motor control circuit with interlocking using normally closed auxiliary contacts to prevent simultaneous contactor operation, preventing short circuits, and driven by start and stop buttons.

Explore fast forward and reverse motor control using a double push button to simultaneously engage forward and reverse contactors, creating a momentary, reversible motor operation.

Design and implement a fast-forward and reverse motor control circuit with two contactors, dual push-button controls, and preservative contacts, comparing NEMA and IEC diagram conventions.

Demonstrates star-delta power circuit basics for starting a motor, wiring the terminals and phase lines, and switching from star to delta with contactors and a timing sequence.

Explore the wiring and control concepts of soft starters in power circuits. Understand circuit breakers, L-terminals, bypass contactors, and connections to star or delta motors, including automatic disconnection as the motor runs.

Explore a complete three-phase soft starter circuit, detailing the power and control circuits, MCCB protection, transformer for control, and bypass contactor operation with stop/start control.