1. Name the three parts of a programmable logic controller (PLC) and explain why the PLC is preferred by designers over electromechanical relays.

2. Medium-voltage circuit breakers operating on system voltages between 600 volts and 15 kilovolts generally contain blow-out coils and a puffer. Describe a puffer.What is its funtion?

3. How is an electrical distribution system protected from lightning strikes? Name and describe the device used and describe its electrical connection to the distribution system it protects.

4. The first step in preparing a primary distribution cable for connection to a transformer, tap box, or other terminal equipment is to remove the semiconducting jacket. The next step is to crimp a flat lug onto the cable connector. List in any order any three of the next six steps in  making the connection.