Airowire Networks Interview Questions and Answers

Single line diagram shows electrical distribution system in simplified form. Circuit breaker schemes depict arrangement of circuit breakers in system.

• Single line diagram is a simplified representation of electrical distribution system showing how various components are connected.

• It includes power sources, loads, transformers, circuit breakers, etc. with lines indicating connections.

• Circuit breaker schemes show arrangement of circuit breakers in system to protect equipment and...read more

CT, PT, and CVT are electrical equipment used in power systems for measurement and protection purposes.

• CT stands for Current Transformer, which is used to measure and step down high currents to a safe level for measurement or protection devices.

• PT stands for Potential Transformer, which is used to measure and step down high voltages to a safe level for measurement or protection devices.

• CVT stands for Capacitive Voltage Transformer, which is used to measure high voltages and p...read more

Various tests are performed on transformers, CTs, and breakers to ensure their proper functioning and safety.

• Insulation resistance test to check for any insulation breakdown

• Turns ratio test to verify the turns ratio of the transformer

• Polarity test to confirm correct polarity

• CT ratio test to ensure the current ratio is accurate

• Contact resistance test on breakers to check for any loose connections

• Timing test on breakers to verify the operation time

Different types of transformers used in substations include power transformers, distribution transformers, and instrument transformers.

• Power transformers are used to step up or step down voltage for transmission and distribution purposes.

• Distribution transformers are used to supply lower voltage to end users.

• Instrument transformers include current transformers and voltage transformers used for metering and protection purposes.

• Examples: Power transformer - 220 kV/33 kV, Distri...read more

Protection scheme in transmission and distribution substations ensures safety and reliability of the electrical system.

• Protection scheme is a set of devices and systems designed to detect and isolate faults in the electrical system.

• It includes various protective relays, circuit breakers, fuses, and other equipment.

• The scheme operates based on principles of fault detection, fault isolation, and fault clearance.

• Different types of protection schemes are used for transmission and...read more