????Check out our ELECTRICAL COMMANDS course from ZERO ➽ https://eletr.co/af6q ...................................................................... ✅ Did you like this video? ✅ Subscribe to the channel ➽ https://eletr.co/industrial ✍️ Leave your comment ???? Share with friends ???? Follow our networks ➽ https://eletr.co/links ....................................................................... Hey my electrician friend!!. Do you know the star-delta starter?, because that is what we are going to talk about in today's video!!. STAR-DELTA SWITCH Introduction The star-delta switch is an auxiliary motor starting device with the aim of reducing the starting current. During starting (especially if it is at full load) a motor can absorb a current, typically, six to eight times its nominal current, so that inertia is overcome. To minimize this condition, some tricks can be used to reduce the starting current, one of which is starting with reduced voltage, caused by temporarily closing the motor in a star. This system is used in motors with two voltages with a relationship (Y-∆) and at least six terminals, the lowest of which must necessarily match the mains voltage. What is done is a connection where the motor is connected to the highest voltage (Y) at the time of starting, applying the lowest voltage (mains-∆) to it. After complete wrapping, the connections are changed and the motor is closed in a delta, making the voltage that the motor receives from the mains the nominal value. Objectives To know and understand how the manual star-delta switch works To understand the power and control diagrams of the automatic star-delta starter To become familiar with the elements of the control system (pushbuttons, protection devices, contactor, signaling LEDs, etc.) and their respective symbols To start the three-phase induction motor using the manual and automatic star-delta switch Characteristics of the star-delta starter Allowed for motors with power from 5 to 15 hp (Local dealership); The mains voltage must match the motor's delta voltage; It can be manual or automatic; The switch can only be applied to motors whose six terminals or terminals are accessible; While connected in star, the coils receive only 58% of the nominal voltage ( ) Connected in delta, the coils receive 100% of the nominal voltage. Star to delta switching is usually done when the motor reaches approximately 90% of the nominal speed. Advantages: Provides a reduction in the starting current to approximately 33% (or 1/3) of its value, compared to direct starting; There is no limit to the number of maneuvers. Disadvantages: If automatic, it uses 3 contactors; In most cases, the start must be no-load; If automatic, it requires a timer relay; With the starting current reduced to approximately 1/3 of the nominal current, the starting torque is also reduced to 1/3. #embaixadordecomandosengehall