Electrical Engineering   SwitchGear & Protection


When is direct-on-line starting used for three-phase squirrel-cage motors? (1)
How do built-in thermal overload protectors work? (1)
How are built in thermal overload protector arranged? (1)
What are the alternatives to the use of overload releases? (1)
What special protection can be provided against single-phasing? (1)
Will normal overload relays trip on single-phasing? (1)
What happens when one of the three lines supplying a three-phase induction motor becomes open-circuited? (1)
How many overload relays are required in the control gear? (1)
How does the magnetic overload relay operate? (1)
How thermal relays work? (1)
What are the usual forms of overload relay in motor-control gear? (1)
What provision must be made for short-circuit conditions in motor circuits? (1)
What devices are required to give adequate protection to the motor? (1)
What are the main functions of control gear? (1)
For an Resistive Load and Inductive load considered for switching operation of circuit breaker, Switching of which load is difficult and Why? (1)
What is re-striking voltage? (1)
When does an arc extincts? (1)
What is recovery voltage in circuit breaker? (1)
Why asymmetrical breaking current is higher than the symmetrical breaking current in a circuit breaker? (1)
Why Isolation switches are provided along with the circuit breakers? (1)
What is meant by Current Chopping? (1)
What are the some precautions must be taken when using a booster transformer? (1)
Why excitation control is not possible beyond certain limits? (1)
Why it is necessary to keep the receiving end voltage constant within specified limits? (1)
What is a booster transformer? (1)
Different methods of controlling voltage in an ac supply system? (1)
How the Voltage Control in power system is achieved? (1)
Purpose of Circuit Breakers (1)
For EHV applications which type of circuit breaker is mostly preferred? (1)
Why current chopping considered as serious drawback in a circuit breaker? (1)