Question { 21082 }

why we cant use AC supply products in DC supply?

Answer

any kind of purely resistive load can be supplied by ac as
well as dc source

Question { 8417 }

WHWT IS USE OF VACCUM CIRCUIT BREAKER

Answer

in practice upto 33KV for quenching arc of current of about
1250 A

Question { 9544 }

What is effect of low pf on HT supply.

Answer

Volatge will go high in this case
and load to be increased on ht side

Question { 4935 }

What happen if the 24 volt DC supply is disconnected from air
circuit breake ?

Answer

at the time of fault trip circuit will not work
and the contacts of the ckt brker will melt due to high
current

Question { IBM, 12400 }

A 4-Pole D.C. Generator has a speed of 1500r.p.m. Then what
will be the frequency of D.C. Generator ?

Answer

50 Hz

Question { 5527 }

what is purpose of manual bybass in ups

Answer

for maintenance purpose
to bypass ups from main line

Question { 5756 }

what is resticted earth fault protection ? how did it
protect & work in power transformer

Answer

REFP is mainly used for high speed tripping on star connected earthed secondary winding of power transformer

The relay does not operate for fault beyond the protected zone i.e neutral of the transformer.

Fault occurring near neutral is having small current becoz of small voltage which results in low fault current. To attend this fault the relay must be too sensitive to operate .To operate, the relay is set for the earth fault current of the order 15%of the rated winding current which protects restricted portion of the winding.

Question { 4272 }

we are small scale industry in production of rice & rice
bran. Pls let me know how to take contract demand for our
industry.. (for information we have total 600.hp)

Answer

First of all please estimate your mill load, office load
(lighting load and air conditioner load).
As per you have shown 600 hp load your contract demand will
be 447.6 kW i.e 527 KVA considering 0.85 power factor