Re Sustainability Limited Electrical Engineer Interview Questions and Answers

CPC CABLE stands for Circuit Protective Conductor cable, which is used for earthing and providing protection against electric shock.

• CPC CABLE is also known as the earth wire in electrical installations.

• It is typically colored green and yellow to distinguish it from other cables.

• The CPC CABLE is connected to metal parts of electrical equipment to prevent electric shock in case of a fault.

High pot test is done to check the insulation of electrical equipment.

• High pot test is done to ensure the insulation in electrical equipment can withstand high voltage without breaking down.

• It helps in identifying any weaknesses or defects in the insulation that could lead to electrical hazards.

• The test involves applying a higher than normal voltage to the equipment to see if the insulation can handle it.

• High pot testi...read more

HT cables are high tension cables used for transmitting electricity at high voltages.

• HT cables are designed to carry high voltage electricity, typically above 11kV.

• They are insulated to prevent leakage of current and ensure safety.

• HT cables are usually made of materials like cross-linked polyethylene (XLPE) or ethylene propylene rubber (EPR).

• They are often armored to protect against physical damage and environmental fa...read more

RCBO combines the functions of an RCD and a miniature circuit breaker, while RCCB and ELCB are older versions of RCDs.

• RCBO combines overcurrent protection (like a circuit breaker) with earth fault protection (like an RCD)

• RCCB is an older version of RCD that only detects earth faults

• ELCB is an even older version of RCD that detects earth faults by measuring the current imbalance between live and neutral wires

• RCBO is com...read more

The ten delta test is a diagnostic test used to assess the condition of power transformers.

• The ten delta test measures the change in power factor between the initial and final stages of a transformer's life.

• It is used to detect insulation deterioration and moisture content in the transformer oil.

• Equipment used for the ten delta test includes a power factor test set, a transformer turns ratio tester, and a megohmmeter.

UPM in data centre involves managing electrical systems, ensuring uptime, and implementing energy efficiency measures.

• Managing electrical systems to ensure continuous power supply

• Implementing energy efficiency measures to reduce costs

• Monitoring and maintaining backup power systems

• Troubleshooting electrical issues to minimize downtime

• Coordinating with other departments for electrical maintenance schedules

Isolation transformers are used to isolate electrical devices from the power source for safety and protection.

• Isolation transformers have primary and secondary windings that are electrically separated to prevent direct current flow between the input and output.

• They are commonly used in medical equipment, data centers, and sensitive electronic devices to protect them from electrical noise and voltage spikes.

• Isolation tr...read more

Power generation involves converting mechanical energy into electrical energy using generators, which is then transmitted through power lines to reach consumers.

• Power generation involves using generators to convert mechanical energy (from sources like turbines, windmills, or water wheels) into electrical energy

• Generators produce electricity by rotating a coil of wire within a magnetic field, creating an electric curren...read more

Precommissioning tests of transformers are essential to ensure their proper functioning.

• Insulation resistance test

• Turns ratio test

• Vector group test

• Winding resistance test

• Magnetizing current test

• No-load loss and excitation current test

• Load loss and impedance voltage test