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.

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wat is d diffr btw shunt coil and trip coil in VCB?

1186

what is ramping rate of generator

369

if we use a normal natural thundering; than approx how much
amount of electricity we generate?

318

In PFI plant one stage capacitor connection is directly
connected(with out megnetic contact controll). but why?

677

Write the programming software name for LG, SIEMENS,Messung,AB

371

I have an existing old MCCB. ABB Model SACE, the rating
are: Ue = 660 volts, Iu =1250 Amps, 3 poles, Ith (max) =800
amps at 45 deg C. I need a circuit breaker for my 3 phase
motors, 380 volts 60 hz. the supplier required the minimum
ampacity of the breaker to be 911 amps. can i use this
breaker with rating of Iu =1250 amps but Ith = 800amps
maximum?

542

what is Insulation monitoring device. where it is used? (in
switchgear room or control panel or in field equipment)

406

What is difference between SMC supportg and Glass Fibre
Reinforced Plastic Support.

444

Grid fault level [KA]?

568

What is the formula to calculate the rating of power cable
for three phase current.

431

1- XC and the RC time constant are both measures of the
reaction of C to a change in ____?
2-The power factor is a numerical ratio with a value
between 0 and 1 equal to the ______________ of the phase
angle.
3-When V and I are out of phase because of reactance, the
product of V times I is called ______________ power
4-For _____________ inductors, the branch currents can be
added algebraically.
5- The ______________ power in watts can be calculated as
I^2R
6-Calculate XL with L = 30mH and f = 1kHz ( I have Xl=2piFL
2*3.141592653*1kHz*30mH
=188 ohms Please check)
7-A parallel RL circuit has the values, R = 5kohms, XL =
5kohms. A voltage source of Vt = 10Vrms is connected in
parallel to R and L. Determine the total current, It
delivered by the voltage source Vt.
8-A series RC circuit has R = 1Mohm and C = 1microF. How
long would it take for the capacitor to fully discharge if
it is initially fully charged?
9-A circuit has real power = 300W and an apparent power of
500VA. Determine the power factor and phase angle.
10-The time constant for an LR series circuit is T = 0.1s
and R = 10ohms. Calculate the inductance L.

1410

What will be the diameter of pipe between conservation tank and transformer

104

why in america the supply frequency is applied as 60 HZ.
but in india we use 50 HZ.

439

UG cable sizes were specified in sqmm. But practically its not coming to mesure. What's the reason for that? And how they specify the size of the cable?

233

what kn of disc is used in 33kv,132kv,220kv,400kv,800kv
transmission line