Exam Question
(a) Sketch a labelled diagram of the power circuit for a star/delta starter. (6)
(b) Explain the sequence of operation of the circuit sketched in (a). (6)
(c) State two advantages and two limitations of the star/delta starting. (4)
ETO
ETO Exam papers
📅 Aug 2021
Reference Answer
(a)
(b) In operation, the main contactor and the star contactor are closed initially and then after a period of time, the star contactor is opened, and then the delta contactor is closed. The control of the contractors is by the timer built into the starter. The star and delta are electrically interlocked and preferably mechanically interlocked as well. The control circuit is provided with a manual stop button and a thermal overload contact to shut down the motor.
(c) answer will be here soon
(b) In operation, the main contactor and the star contactor are closed initially and then after a period of time, the star contactor is opened, and then the delta contactor is closed. The control of the contractors is by the timer built into the starter. The star and delta are electrically interlocked and preferably mechanically interlocked as well. The control circuit is provided with a manual stop button and a thermal overload contact to shut down the motor.
(c) answer will be here soon
Prepare on Android — MeoMock on Google Play