AECOM Senior Engineer Interview Questions and Answers

Bus bar schemes are different ways of connecting bus bars in power systems.

• Single bus bar scheme

• Double bus bar scheme

• Main and transfer bus bar scheme

• Ring bus bar scheme

• Breaker and a half scheme

• Mesh bus bar scheme

The equipment sequence for any line bay starts with the circuit breaker and ends with the transformer.

• The circuit breaker is the first equipment in the sequence.

• Next comes the isolator switch.

• After that, the earth switch is operated.

• Then the line disconnector is opened.

• Finally, the transformer is disconnected from the line.

• The sequence is reversed when the line bay is put back into service.