Why Humming noise originated in Starter motor and how it was generated ?

3 Answers  

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If we use 250A MCCB as a incomer in Control panel for a fault level of 50kA for one second ,assuming temperature rise from 85 Deg. to 100 Deg , Then what will be the Aluminium Bus-bar size for 250A MCCB? Explain in detail.

0 Answers   Usha Capacitors,

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how to claculate earth strip size for 1500kVA transformer for neutral and body

4 Answers  

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what are the duty ratings in DG sets?

1 Answers   L&T,

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According to IEC60034-14, When the vibration monitoring system required for motor Bearing. above which KW, it is required? and for what type of bearing the vibration probe is provided.

0 Answers  

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how to check ac servo motor

0 Answers  

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what is volt drop formula?stm

1 Answers  

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I am an electrical power engineer and arranged power system for a data center, I installed MCB, ELCB and erthing system TN-C-S. But some times several ELCBs Disconnect circuits at the same time! what may be the reason? (the ELCBs are 25A ,30mA)

9 Answers  

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What is the use of Exciter in generator? & what will be the current of Exciter in 500 KVA DG Set?

2 Answers  

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Why Exciter higher ferquency ?

1 Answers   Core Logic,

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11 kV line deraction check by an Engineer.

0 Answers  

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I have connected 04nos. earthings to a transformer through 04nos. earthing pits seperately. 02nos. earthings are connected to T/F body, and 02nos. earthings are connected to T/F neutral.T/F capacity is 2000KVA, 11KV/415V. But after completing of 02 years successful operation ,we are facing following problems- 1. CT/PT occured blast one time 2. HT cable box occured blast two times 3. One body earthing strip and one neutral earthing strip of transformer are overlapping at some places. Whenever these two strips are pressed at overlapped points, they made spark. What is the reason of spark? Please explain the reason & rectification of above problems

5 Answers  

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