Protection Schemes and Automation Basics

What they ask

After an online HR interview, the technical round happens at the company premises with the hiring manager. For fresh graduates it starts soft (your GPA, how eager you are to learn new technologies, what you covered in your graduation project) and then moves into two technical areas: protection schemes and basic automation.

Questions in this area, for example:

Protection

• Name the main protection functions on a distribution feeder (overcurrent, earth fault, differential, distance) and say what each one detects.
• A downstream breaker should have tripped first but the upstream one did. What does that tell you about coordination, and how would you fix the settings?
• Difference between a fuse, an MCB and an MCCB, and where you would use each.

Automation

• Open loop versus closed loop control, with an example of each from a building or a factory.
• What is a PLC, what languages can you program it in, and what does a ladder rung for a start/stop latch look like?
• A SCADA screen shows stale data from one PLC. Walk through how you would troubleshoot the connection, from physical layer up to tags.

What they look for

• Textbook-level correctness with clear vocabulary; you are not expected to have commissioned a substation.
• Structured troubleshooting: check power and cabling, then link status, then IP and protocol settings, then the tag configuration.
• Curiosity. Saying "I have not used that product but here is how I would learn it" scores better than bluffing.