Any one can explain if there is any harm from humming noise
heard from air circuit breaker : we have 415 switch board
having two incomers from transformers 3.3KV/415V , when bus
coupler closed, and open one ACB incomer to work in one of
the transformers, the current started hunting around 50
Amps, and heard humming noise from the air circuit breaker,
although the load current was only 1200 amps while the ACB
capacity is 2500 Amps, and the transformer 1600 KVA. The
same didn't happen when taken the other transformer offline.
Why this humming noise and current fluctuation? is there
any implication or danger, bearing in mind that we just
returned everything back to normal and stopped the
maintenance of the transformer. Shall we go ahead and
ignore this noise?
Answer Posted / yusuf
Can you tell me what is the circuit Breaker settings like
overload,shortcircuit,ground fault & Instantaneous s/c
settings.Acc to your details max load that can be derived
from X'mer is 2228.56 amps & from 800 amps onwards Breaker
is creating this problem.So around from 25% load CB is
creaing problem also tell me about any release installed
(Closing,shunt,undervoltage).
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
WHY THREE PHESE SYSTEM VOLTAGE APPLIED IN 440 VOLT
different aspects of voltage stability
Why space heater is required for each verical bus bar chamber? if one space heater is adequate or not for anti condensation?
What will be result if we connect LT votage to the terminal of HT motor?
Is it possible to use a S1 duty class motor for crane application (S4)? If not, why?
1. Can a 12v DC choke operate a 60v/12w PL lamp ? 2. Can a 230v ballast fire / operate a 60v/12w PL lamps.
How select ELCB for 32amp. socket having quantity 12Nos. We have to do this wiring in PLANT. Please Also explain the incoming cable specification.
if an insulated power and control cables of a running gas diesel gensets laid direct in an open trench i.e, trench bed is not rcc of a power house in which rain water, spillage water alwas exists and all power control cables remains submerged even when gas gensets of 480 kw each runningin on load. These power &control cables runs from power house to switchgear room through these trenches in which water remains most of the time. pl explain its merit & de-merit
WHAT IS MEANT BY OVER EXCITATION IN GENERATOR TRANSFORMERS? DESCRIBE IT.
what may the reason for vector shift in a generator?
What is meant by load angle of an alternator? Upon what factors does the load angle depend?
What is formula calculation size cable wire ?
Difference between a pilot wire and a normal conductor?
hi frenz,its aswathy.i hve aplied for the hpcl test on feb,pls send the test patern & the placement papers as soon as possible. mail-id :kjaswathy@gmail.com
at what basis/standard we have to arrive the current density of aluminium/ copper in busbar?