Motor Control Circuits & Industrial Electrical Controls 2026

Learn about common control switches, including green and red push buttons, emergency switches, and two-way and three-way selector switches, with IEC and jack symbols used for control drawings.

Understand miniature circuit breakers (MCBs) and their protection from overcurrent via magnetic short-circuit trips and thermal overload, including types B, C, and D and motor applications.

Explore contactors, electromechanical devices that remotely energize three-phase motor circuits via coil action, switching normally open and normally closed auxiliary contacts to enable auto control.

Relays are electromechanical devices that control circuits by energizing a coil to switch normally open and normally closed contacts, with various pole configurations and flyback diodes.

Learn how thermal overload relays protect motors from heat caused by overcurrent by sensing winding temperature and sending a trip signal to a contactor, not directly cutting power.

Explore how timers in control circuits provide timing control and energize coils by switching contacts. Learn about on-delay, off-delay, and cyclic timer types and their practical applications.

Master the latching circuit: energize a relay coil with a start push button and use a holding contact to keep power, then stop with a stop push button.

explore how a direct online starter powers a three phase motor with a contactor, MCP protection, overload relay, and a control circuit with start, stop, latching, and emergency switch.

Introduce the CADESIMU ECMO software for simulating electrical control circuits. Learn to configure power feeds, fuses, overload relays, contactors, star-delta starters, and ladder logic with 2D and 3D drawings.

Master CADESIMU wiring for motor starters by avoiding duplicate overload relays and end-to-end connections, preventing invisible overlaps that stop simulations and keeping wiring clean to ensure successful operation.

Simulate a direct-on-line starter circuit in CADESIMU, wiring the power circuit with MCB, contactor, overload relay, and motor, and the control circuit with emergency stop and push buttons.

Demonstrates wiring a dual starter from power to control circuits, including circuit breakers, overload relay, contactor, latching circuit, emergency stop, and a delta-connected motor with LED indicators.

Explore how a three-phase induction motor works, including star-delta starter, stator windings, rotor bars in a squirrel cage, and the rotating magnetic field that induces current and drives rotor motion.

Explore induction motor behavior under no-load, gradually loaded, and high-torque start scenarios, examining current, windings heating, slip, and overload relay tripping, with star-delta voltage reduction as a startup solution.

Explain single-phase and three-phase voltages, including line-to-line and line-to-neutral, and the relationship vline = sqrt(3) vphase. Also discuss typical voltages and how to connect motors to apply these voltages.

Explore motor windings and terminal box layouts for a three-phase motor, covering U1/V1/W1 and U2/V2/W2, star and delta connections, and how to connect the three power lines.

Explore star and delta connections, calculate phase and line voltages and currents, and understand inrush current managed by a star-delta starter.

Read the motor nameplate and match supply voltage to its rated voltage to decide star or delta connections for a star-delta starter.

Explore star-delta power circuits by wiring the motor in star and then delta, using MCP, main and star contactors, and overload relays, with multiple connection methods.

Learn to implement a star delta starter control circuit with a dual starter, a 10-second timer, interlocks, and sequential star-to-delta switching, plus safety and simulation steps.

Illustrates building a star-delta starter with power and control circuits, wiring main, delta and star contactors, overload relay, timer, interlocks, start/stop buttons, and LED indicators in a CADESIMU simulation.

Build a star-delta starter by adding a timer and interlocks. Wire the delta and star contactors, connect the motor, and test the control circuit with overload protection.

Learn how to reverse a motor with forward-reverse power and control circuits by swapping two phases, using interlocks and latching relays, and testing direction with a phase rotation meter.

Explore forward and reverse motor control using contactors, an overload relay, and interlocks, with LEDs signaling direction, trip, and off status in a simulated power and control circuit.

Build a forward and reverse motor control circuit using contactors, auxiliary contacts, interlocks, and an overload relay, with emergency switch, start/stop pushbuttons, and indicator LEDs.

Covers a water pump with a pressure switch, maintaining pressure between 3 and 6 bar by turning pump on at minimum and off at maximum using a control circuit.

Explain a pressure controlled water pump circuit with a three-phase MCP, contactor, and overload relay. Outline control path with start/stop buttons, pressure and float switches, and the emergency switch.

Simulate a water pump circuit in CADESimu, wiring MCB, contactor, overload relay, and a motor with pressure and float switches for auto on/off with water level.

Size the MCP contactor and overload relay by calculating the full-load current from motor nameplate data (power, voltage, pf, efficiency) using the three-phase formula for dual and star-delta starters.

Learn to size miniature circuit breakers for three-phase motors using NEC table 30.52, apply inverse-time protection, use a 150%–250% full-load current multiplier, and select 16–32 A MCBs with D-type options.

Size cables at least 125% of full load current per the NEC to prevent overheating, and choose copper to meet the calculated 13.23 A.

Size the thermal overload relay for dual starter using NEC 430 rules and a service factor of 1.15. Compute 12.17 A from 10.59 A and select 9-13 A relay.

Learn to size a contactor for motor starters using the 125% of full load current rule, select the proper AC duty type, and match coil voltage to prevent coil damage.

Size cables for a star-delta starter using NEC 125% of full-load current, compute line and phase conductor ratings, and use equal ratings for both delta and star to handle inrush.

Explore where to install thermal overload relays in star-delta starters, the four mounting methods, and how to size them using line vs phase current and 115% of full load.

Learn to size dual and star-delta power circuits with a cheat sheet: equations for full-load current and recommended MCP contactor, thermal overload relay, and cable ratings per NEC guidance.