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MENGENAL   TAMPILAN AUTOCAD 2007 Tool Bar Tree Menu   Drawing Area Command Dialog Keterangan : Tool Bar                                   : Merupakan Tool/alat yang biasa digunakan dalam pembuatan gambar Tree Menu                             : Merupakan Menu Utama dimana didalamnya terdapat perintah-perintah                         ...

Electronic Over Current Relays Posted by bayupancoro in bayu pancoro , electric , Electric fo Dummies , listrik , product . Tags: Electric fo Dummies , EOCR , listrik , motor protection relay , protection relay trackback Overload elektronik EOCR mempunyai fasilitas proteksi yang lebih banyak dan lengkap dibanding thermal overload . Arus yang mengalir pada integated CT di monitor dan diambil dengan rangkaian elektronik yang ada didalamnya. Data tersebut kemudian diolah oleh MCU yang ada didalamnya untuk acuan proteksi atau display yang dihasilkan. Beberapa sistem proteksi yang ada pada EOCR adalah sbb : Overload protection, proteksi jika kelebihan beban ampere. EOCR akan trip jika arus motor (In) melebihi setting overload (Is) untuk waktu yang lebih lama dari  O-Time. Phasseloss protection, proteksi jika salah satu fasa putus. Pada saat terjadi phase loss arus motor akan naik sekitar 150 % atau lebih. Kenaikan arus ini akan mengakibatk...

Star-Delta Starter March 16, 2012 62 Comments Introduction: Most induction motors are started directly on line, but when very large motors are started that way, they cause a disturbance of voltage on the supply lines due to large starting current surges. To limit the starting current surge, large induction motors are started at reduced voltage and then have full supply voltage reconnected when they run up to near rotated speed. Two methods are used for reduction of starting voltage are star delta starting and auto transformer stating. Working Principal of Star-Delta Starter: This is the reduced voltage starting method. Voltage reduction during star-delta starting is achieved by physically reconfiguring the motor windings as illustrated in the figure below. During starting the motor windings are connected in star configuration and this reduces the voltage across each winding 3. This also reduces the torque by a factor of three. After a pe...