Deepakkumar Yadav
Separate source voltage withstand test of Transformer (Power frequency) Q. Explain with neat sketch power frequency high voltage test on transformer. Before commissioning the transformer it is necessary to know that the insulation resistance of a transformer is greater than a specified value, to avoid excessive leakage currents. Megger test for insulation are carried out … Read more
Impulse Test of Transformer Q. State how insulation resistance of a transformer is measured. Measurement of Insulation Resistance of Transformer Before commissioning the transformer it is necessary to know that the insulation resistance of a transformer is greater than a specified value, to avoid excessive leakage currents. Megger test for insulation are carried out between … Read more
Testing of Electrical Transformer (A) Polarity Test (B) Phasing Out Test (A) Transformer Polarity Test The H.V. and L.V. terminals of a single phase and three phase transformer should always be marked as shown in Figure (IS 2026-1962). For a 3 phase transformer, viewed from H.V. side the arrangement of both sets of terminals shall … Read more
Why Transformer Neutral Connected to Earth Distribution systems are earthed to create a reference point for the system voltage, to facilitate the detection and discriminative isolation of faults involving contact to earth, and to limit over-voltages under transient conditions. A neutral earthing system is a system in which the neutral is connected to earth, either … Read more
Electrical Faults and Electrical Faults Causes Failures which are mechanical in nature are very slow and show some visible signs of their approach. But electrical failures are sudden and without any pre-warning, excepting to an experienced person. After the electrical installation is commissioned, it normally works alright. Failures however rises later on due to the following causes … Read more
Oil Circuit Breakers : Q. State the required properties of oil in CB. Q. What is Oil Circuit Breaker. Search Results Web resuQ. What is Oil Circuit Breaker Properties of oil in C.B. : It should have high dielectric strength. It should have good thermal conductivity. It should have high breakdown strength. It should have low … Read more
Low oil Circuit Breakers (MOCB) Q. Draw neat diagram MOCB. Explain its working. Q. Draw a neat labeled diagram of MOCB. In case of bulk oil circuit breaker oil is used for two functions. – Firstly it acts as an arc-quenching medium and … Read more
Vacuum Circuit Breakers (VCB) : Q. Explain, construction, working principle of vacuum circuit breaker with neat diagram. Q. Explain the principle and working of vacuum circuit breaker. Q. Explain working of vacuum circuit breaker with neat diagram. Q. Draw neat diagram of vacuum circuit breaker and explain its operation and state its applications. Since vacuum … Read more
Current Transformers : Q. State the specifications of CT as a protective transformer. Video :- The instrument transformers, which used in conjunction with ammeter, over current relay etc. are known as current transformers. Current transformers step down current from high value to a low value. Their current ratio is substantially constant for given range of … Read more
Melded Case Circuit Breaker (MCCB) : Molded case circuit breakers are tested and rated according to the UL489 Standard. Their current carrying parts, mechanisms and trip devices are completely contained within a molded case of insulating material. MCCBs are available in various frame sizes with various interrupting ratings for each frame size. Molded case circuit breakers are designed … Read more