Starter Star-Delta Otomatis dengan Timer: Daya, Kontrol & Diagram Penyaluran Daya Motor AC 3-Fasa

Automatic Star / Delta Starter with Timer for 3-Phase AC Motors

Dalam tutorial ini, kami akan menunjukkan Metode Pemulaian Induksi AC Motor 3-Fasa Star-Delta (Y-Δ) dengan Automatic star-delta starter with Timer dengan skematik, daya, kontrol dan diagram penyaluran daya serta cara kerja star-delta starter dan aplikasinya dengan keuntungan dan kerugian.

Automatic Star Delta Starter with Timer Wiring & Installation Diagram

Penjelasan cara kerja dan operasi Star Delta Automatic Starter with Timer Wiring Installation:

Dari kiri Anda memiliki contactor utama dengan timer pneumatic karena contactor utama Anda selalu terdayakan, di Tengah Anda memiliki Delta contactor dengan thermal overload untuk perlindungan motor jika motor melebihi rating ampere yang diatur pada thermal overload, di kanan Anda memiliki Star contactor yang merupakan contactor pertama yang dienergikan dengan contactor utama lalu ketika timer mencapai batas waktunya Star contactor de-energizes dan Delta contactor energizes dan Motor berjalan pada beban penuh.

Related Motor Control & Power Diagrams:

• STAR/DELTA Starter Without Timer Power, Control Diagrams & Wiring Diagrams
• Control 3-Phase Motor from more than Two Places – Power & Control Diagrams

Operation & Working of Automatic Star Delta Starter

Dari L1 arus fasa mengalir ke kontak thermal overload melalui fuse, then OFF push button, On push button Interlocking contact 2, dan kemudian C3. Dengan cara ini, rangkaian selesai, sebagai hasilnya;

1. Contactor coil C3 dan timer coil (I1) dienergikan sekaligus dan gulungan motor kemudian dihubungkan dalam Star. Ketika C3 dienergikan, auxiliary open linksnya akan tertutup dan sebaliknya (i.e. close links akan terbuka). Jadi C1 Contactor juga dienergikan dan Three Phase Supply akan mencapai motor. Karena gulungan dihubungkan dalam Star, maka setiap fasa akan mendapatkan √3 kali lebih kecil dari tegangan garis i.e. 230V. Oleh karena itu Motor mulai dengan aman.
2. Close contact C3 di baris Delta terbuka karena tidak akan ada kemungkinan aktivasi contactor 2 (C2) .
3. Setelah melepaskan push button, Timer coil dan coil 3 akan menerima suplai melalui Timer contact (Ia) , Holding contact 3 dan close contact 2 dari C2.
4. Ketika Contactor 1 (C1) dienergikan, maka dua open contact di baris C1 dan C2 akan tertutup.
5. Untuk waktu tertentu (biasanya 5-10 detik) di mana motor akan dihubungkan dalam star, setelah itu Timer contact (Ia) akan terbuka (Kami dapat mengubah dengan memutar knob timer untuk menyesuaikan waktu lagi) dan sebagai hasilnya;

• Contactor 3 (C3) akan mati, karena open link C3 akan tertutup (yang ada di baris C2) sehingga C2 juga akan dienergikan. Demikian pula, Ketika C3 mati, maka star connection gulungan juga akan terbuka. Dan C2 akan tertutup. Oleh karena itu, gulungan motor akan dihubungkan dalam Delta. Selain itu, Contact 2 (yang ada di baris C3) akan terbuka, sehingga tidak akan ada kemungkinan aktivasi coil 3 (C3)
• Karena motor sekarang dihubungkan dalam Delta, maka setiap fasa motor akan menerima tegangan garis penuh (400V) dan motor akan mulai berjalan dengan gerakan penuh.

Related Post:

• Why We Need to Install a Starter with a Motor?
• Difference between Star and Delta Connections – Comparison Of Y/Δ

Star Delta Starter Power Diagram

Control Diagram of Star Delta Starter with Timer

Wiring Diagram of Star Delta Starter with Timer

Abbreviations: ( FOR Control Wiring of Three Phase Star Delta Starter with Timer)

• R , Y, B = Red, Yellow, Blue ( 3 Phase Lines)
• C.B = General Circuit Breaker
• Main = Main Supply
• Y = Star
• Δ = Delta
• 1a = Timer
• C1, C2, C3 = Contatcors (For Power & Control Diagram)
• O/L = Over Load Relay
• NO = Normally Open
• NC = Normally Closed
• K1 = Contactor (Contactor coil)
• K1/NO = Contactor Holding Coil (Normally Open)

Advantages & Disadvantages of Star Delta Starter with Timer

Advantages:

• Simple Design and Operation
• Comparatively cheaper than other voltage controlling methods
• Torque and Current performance of the Star delta starter is well.
• It draws two times starting current of the FLA (Full Load Ampere) of the connected motor.
• It reduced the starting current to one-third (approximately) as compared to DOL (Direct ON Line Starter)

Also read:

• Three Phase Motor Connection Reverse and Forward Power and Control wiring diagrams
• Two Speeds One Direction Three Phase Motor Connection Power and Control Diagrams

Disadvantages

• Starting Torque is also reduce to one-third because starter reduce the starting current to one-third of the rated current [as Line voltage also reduced to 57% (1/√3)]
• It required Six leads or terminals Motor (Delta Connected)
• For Delta connection, the supply voltage must be same as the rated motor voltage.
• At switching time (From Star to Delta), if the motor does not reach at least 90% of its rated speed, then the current peak may be equally high as in Direct ON Line starter( D.O.L), thus it may cause harmful effects on the contactors contacts, so it would not be reliable.
• We may not use star delta starter if the required (application or load) torque is more than 50% of the three phase induction motors rated torque

Related Post:

2 Speeds, 2 Directions Multispeed 3-phase Motor Power & Control Diagrams

Characteristics & Features of Star-Delta Starter

• The starting current is 33% of full load current for star delta starter.
• The peak starting torque is 33% of full load torque.
• The peak starting current is 1.3 to 2.6 of full load current.
• Star-Delta Starter can be used only for low to high power three phase induction motors.
• It has reduced starting current and torque.
• The 6 connection cables are needed for motor terminal box.
• In Star Delta starter, Current peak and mechanical load on changeover from star delta

Applications of Star Delta Starter

As we know the main purpose of star delta starter is to start the three phase induction motor in Star Connection while run in Delta Connection.

While keep in mind that Star Delta starter can only be used for low to medium voltage and light starting torque induction motors. In case of direct on line (D.O.L) start, the receiving current at motor is about 33% while the starting torque reduced about 25-30%. This way, Star Delta Starter can be only used for light load during starting the motor. Otherwise, the heavy load motor wont start due to low torque which need to accelerate the motor to rated speed while converting to the Delta connection.

You may also read other power & control diagrams below:

• What is Motor Starter? Types of Motor Starters and Motor Starting Methods
• What is Soft Starter? Its Working, Diagram and Applications
• Direct Online Starter – DOL Starter Wiring Diagram for Motors
• What is a Contactor ? Types, Working and Applications
• Three Phase Motor Power & Control Wiring Diagrams