Answer / r.k. gupta

We are using IGBT & SCR in UPS system because these are high frequency switching with high current devices. which are used in UPS for inverting the supply from DC to Ac during battery backup of UPS. 

what is Over current, earth fault (O/C+E/F) ?

2 Answers  

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how to checking earth restence with earthtester

1 Answers   NTPC,

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Explain the power rating of a bulb, say 60W, what if the voltage changes

4 Answers  

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Why ELCB trip, when neutral touch with ground?

1 Answers  

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According to general circuit diagram of 1-Phase t/f , why the primary is not get short circuited ,even though the supply terminals both are directly connected through primary winding?

4 Answers  

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what is the function of open delta System?

1 Answers  

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For the same power rating,which motor is bigger in size,AC or DC?

9 Answers   Bhel,

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why current flow to the opposite direction of flow of electrons???????????

0 Answers   Bhel,

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number of I/O devices in siemense plc

0 Answers   EB,

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What are your future expectations from this company and how long do you intend to work with this company if employed?

1 Answers  

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I have a 5KVA UPS. Total load to be connected almost 3KW. Ordering a battery pack with capacity of 1920VAh. How long will the backup time be?

1 Answers  

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If there is no problem with the electronic circuit and regulator then why the motor start rotating at low value of regulator with full speed both at laod and no load??? and if my judgement of circuit is wrong then what is your openion?

1 Answers  

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