In case of Star Delta starter the motor intially will run
in star connection and when 80% of rated speed picks, the
motor change over to delta connection. With this star delta
connection we are able to reduce starting current by 1/3 of
DOL starting current and starting torque also.
Please Help Members By Posting Answers For Below Questions
why various test are performed on electrical panels & power
cables before commissioning on site & what are these test???
My question is whether bellow formula is correct to find bus size for 46kA for 0.5 second & what is RT in bellow formula.
formula to calculate the size of busbar to withstand the thermal stresses due to currents with duration of 0.2 sec to 5 sec.
Sp = RT( I x I x t) / K
Where Sp – is the cross sectional area of bus bar in millimeters.
I - is the value of AC fault current.
t - is the operating time of disconnecting device in seconds.
K – is the factor depending on the material of the conductor, insulation and initial and final temperature.
Value of ‘k’ for copper is 143.
in a solar power plant,we are going to step up the voltage 350V to 33kv, and to 132kv GSS.
i want to ask that if it is possible that 315v/33kv is not possible because we also use 315v/11kv. or it should be 415v/33kv? is it effects generation or losses?
the second question is-generation is depends on LV winding? or LV winding design for generation voltage?
why -48 volts dc used in telecommucation
what is the range of thermal overload and over current.
Answer should be in percentage of current.
if any body have question paper of railway (section
engineering),then plz send me .i will thank of him/her.
What type of wiring series or parallel is used for
conventional and addressable type FAS & why?
2. A current i=(10+10 sin t)amperes is passed through MI
type ammeter. its reading will be.........
2. Modify your design in question 1.a so that the circuit
works according to the following function table
X Y F
0 0 Clear
0 1 No Change
1 0 Parallel Loading
1 1 Count
3. Design a circuit that detects the pattern 010 in a serial
input X considering:
3.b No overlapping
please send me the L&T Emb. sys. placement papers and
entire details of pattren
In DC generator, we use commutator, having no. of segments.
Then how it is possible to get a half wave of voltage and
current for half rotation of armature?
high voltage transformer input voltage,current and amps
rating..distributed transformer input voltage,current and
For small size, high frequency coils, the most common core
c.) Powdered ion
what is an unbalance in acircuit? in a three phase 3wire
circuit how an unbalance will come? in a three phase four
wire system how an un balance is coming?