Electrical Switchgear

Electrical switch gear is on of the important part of electrical system. the purpose is to provide switching function, control function and protection of the system. Usual switch gear elements are- circuit breaker, relay, magnetic contactor, solenoid, instrument transformer- current transformer, voltage transformer etc.

1. Circuit Breaker

  1. Function and rated characteristics of circuit breaker – all things need to know of circuit breaker (1 of 3)
  2. Rated frequency, operating sequence, short-circuit & out-of-phase breaking current characteristics of circuit breaker. (Part 2 of 3)
  3. How to select Fuse or Circuit Breaker for group of motor in same branch circuit as per National Electric Code.
  4. Arc Fault Circuit Interrupter (AFCI)- circuit breaker that prevents electrical fire causing arcing.
  5. RCB – Residual circuit breaker to detect earth fault ; how it works.
  6. Ground or Earth fault protection Relay- RCB, RCD

2. Relay

  1. 1.Basic of Relay – definition, configuration and symbols.
  2. 2.Relay accessories devices
  3. Types of Relay based on working principle.
  4. A brief insight on directional relay- its function, theory and use.
  5. A brief insight on relay auxiliary switch or contacts.
  6. Over Current Relays
  7. Ground or Earth fault protection Relay- RCB, RCD
  8. Time delay relay – types and categories.
  9. Purpose & details on Trip circuit Supervision Relay -TSR.
  10. How to obtain variety of operation with auxiliary relay by adding accessories.
  11. Electrical Ladder diagram- definition and details.
  12. How to implement control logic gate with relay.
  13. Pick and place robot control with timer relay.

03. Magnetic devices

  1. Magnetic Contactor- construction & how it works.
  2. Solenoid types, parameters and practical application area.
  3. Solenoid application area and its limitation.
  4. Solenoid basic working principle and a practical Solenoid valve.
  5. What is AC-hum & Contact bounce in Magnetic Contactor.
  6. How to do maintenance of contacts in Magnetic Contactor.

4. Instrument transformer

  1. Instrument transformer installation and maintenance- complete list of precaution and instructions.
  2. Instrument transformer – application and types.
    Current transformers, Voltage transformers in brief, Function of Instrument transformers.

Current Transformer

  1. Non-magnetic current transformer with Rogowski coil & its advantages.
  2. Current transformer- definition, basic function, composition, types & rating.
  3. CT burden, Knee point voltage & Magnitization curve- details of Current transformer.
  4. Basic connections of current transformer to a circuit.

Voltage or potential transformer (PT/VT)

  1. Basic of voltage/Potential transformer. Definition, function of VT/ PT | Why secondary of VT/PT must not be shorted | Composition of VT /PT | Types of VT/PT.
  2. Connection of Voltage / Potential transformer. Basic connection of VT/PT | Metering connection arrangements for VT/PT | Measure residual voltage with PT/VT | Internal connection of PT / VT.
  3. Why a voltage transformer should not be connected in short circuit – explained by equations.