Answer / monty

LBB called as a line breaker back up protection and it is used for the saftey of our equipment whenever fault occurs on line than the breaker of uper stream will be open if lower stream breaker will not operated.

Answer / tpfasil200

Local breaker backup or breaker fail relay(LBB)..It is used when the trip command is given and the breaker fails to open due to some mechanical problem. The protection is time delayed and initiated by all trip conditions.On LBB operation, busbar protection is initiated, as all the breakers connected to that particular bus to which the circuit is connected have to be tripped.I t also trips the tie breaker and sends a direct trip command to the other end breaker.

can we transmit power with out cable if it is possible how it is possible.

2 Answers  

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how can we calculate the current

3 Answers  

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why generator and t/f ratings given in kva & motor rating is in KW?

6 Answers  

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temp of cast resin 1500kva tx formerwent up to 138.c but came down very fast to about 100.c within 20 mins when load was reduced from 70% to 60%

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If we have 15000kw connected load in a factory than how much power demand sanction should be taken from electricity board. Pls provide complete calculation.

3 Answers  

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How we calculate the average power factor if the one phase is lag and another one is in lead?

1 Answers   DigiTech, MCR,

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wat s reactive power.... how could it be compensated.....

4 Answers   TCS,

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what kinds of Transformer oil grade is better for power transformer ?

0 Answers   KSRM Steel Plant,

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State the types of distortions in amplifier?

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Can neutral line also be use as a earthting for distribution transformer, or we need separate earthing pit forh the transformer?

1 Answers  

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how does this job compare with others you have aplied for?

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Why the earth to phase voltage is high 250 compare to other two phases

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