Answer Posted / nilesh kumar singh
Selection of Circuit breaker
CURRENT RATING:
Transformer Rating (X)kVA
%age impedance of transformer - Z%
I Full load = X*1000/Sq. root 3*VL
Where X = Transformer rating in kVA
VL = Line Voltage
BREAKING CAPACITY:
Breaking Capacity of the breaker> I Fault Current
Fault Current (Level) = 1.1*VL/Sq. root 3*Z
Where Z = Impedance of Transformer
VL = Line Voltage
Z= %Z*10*(kV)*(kV)/KVA
MAKING CAPACITY:
Making Capacity depends upon the following:
a) Power Factor
b) Instant of switching ratio 'n' between required rate s/c
making capacity and rated s/c breaking capacity.
Is This Answer Correct ? | 66 Yes | 12 No |
Post New Answer View All Answers
I am EEE student i want to improve my core side skills.how cn i approach it?
How to design the NGR Resistance
Is there any type of starter for DC motor other than two point,Three point and Four point starters?
Explain marx circuit.
What is the method for testing the differential protection stabilty in generator? When the time of starting What will happen if differentail protection connection wrong means?
following are the questions asked in interviews: 1) Considering the short circuit fault, which switchgear is preferable, SFU OR MCCB? Which operates faster? whicg one is popular in Indian Market and why? 2)Define SCPD. What is type2 coodination? 3)Why the contactor rating is higher for the fuseless selection than for fuse selection? whether the ratinf of SFU or MCCB remains the same in both the cases? 4)If the HP rating is known then can you calculate the ratings of L.V Switchgear(SFU/MCCB, contactor, OLR) without using the selection chart?
lamination figures
write down the formula of cable size in RM if current is 50Amp.
The inventer is a battery, but if lost current at home u will turn on the fan but the is AC and inventer battery is dc . Then how the fan was rotating. What device Or machine in fan converst the Dc power to Ac power
where rlc series ckt used?
What is voltage divider rule?
how will we calculate the copper wire load..
what is the maintaining Cf in UPS.
Define bibo stability.
if there are six generators (3 gas CATT, one Jenbacher o1 MW each, and two nos Diesel 01 no 01 mw other 0.65mw EDGs ( say), 3 CAtt gas set have identical pole pitch,01mw EDG and Jenbacher gas Set have different pole pitch, how their power connection can be done to connect a common bus bar during installation. in short, how different pole pitched generators power connection can be done to connect a common busbar system through generators incomer ACBs.