Answer / satya dev

1-Over current & earth fault relay for feedar Protection.

2-reverse power relay for Alternators ( if diffrent
sourcees are used- eg. transformer supply & DG supply)

3-Inverse/differetial relay for Busbar protection.

Answer / vel

over current and earth fault relays (2OL+1EL method)are
used for lv .

Answer / jagadisha.n bmsit

Different protection systems which is used in LV panels are:
1. Short circuit protection :- It is done by choosing set
point in sc protection relay which is present inside the CB's.

2. Thermal protection for Busbars/ cables:- Bec extreme
thermal point cause flash over

3. Over current protection

4.Protection provided by proper shielding & interlocks such
that operator & maintenance people can not accesses live parts

Answer / sachin

1.over current reley
2.earth fault reley
3.fase failure relay
3.fuse moniterning relay.

Answer / nagesh

current protection
1)over current
2)short ckt current
3)Instantanious current
Earth fault relay,
Negative phase sequence
Phase failure
If require
High temprature
High vibration
Safety (door switches)
MD over shoot(MD monitoring)

Answer / vinod

VCB,ACB,MCCB

shall we use a machine having 60Hz frequency in india ? why?

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Transformer calculation

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differtiate between energy consevation and energy efficiency..

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Hi to u all : Friends: Why when operate on 2 phase welding machine the power metr goes reverse ?? the meter is god on other loads. thanks

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750kva 11/415kv transformer having percentage impedence is5.64%. 11KV HV whose current 39.37A and 415V LV whose current 1043.43A.resistance is 2.5ohm. find no load loss and full load loss?

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1.stranded resistance values of motors? 2.how to calculate the resistance values of single phase and 3phase motors?

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what is the permissible bend in the LT& HT CABLES.

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what is tertiary winding in transformer?What is its purpose?

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how c-curve of mcb's actually looks alike?

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For 300MW and over a distance 250 km, what voltage be selected? and no. of circuit?

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if we going for high voltage usages what are the considering factors, why those factors are effected.... please give me an answer related motor factors like wnidnig, frame, temp etc

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Is it true online ups having bypass mode if it is true then why we called ups because it is interrupting power when goes in bypass mode

0 Answers