Interested to Buy Any Domain ? << Click Here >> for more details...
Answer Posted / ammar
we have to calculate the rated current of the load
connected to the circuit breaker from the power equation
p=√3.V.I.cosθ
then we can decide which is the suitable rating for the CB.
| Is This Answer Correct ? | 10 Yes | 3 No |
Post New Answer View All Answers
WHAT IS DEGREE OF COMPOUNDING IN D.C MACHINE MEANS? HOW TO READ THE OPERATING CHART FOR ANY ELECTRICAL MACHINES?
What is called grain-oriented laminations?
why Current is lead 90 degree and voltage is lag 90 degree in a capacitor.? why Current is lag 90 degree and voltage is lead 90 degree in an inductor.?
explain different types of d.c motors?
Can we use BS 6651 and BS EN 62305 standards for computer room lightning ptotection in substation?
Starting Time of LT & HT Motor
What is the angle of inclination for the oil connection from transformer conservator to Bucholz relay and why?
1. A bomber drops a bomb from an aircraft flying at 2000 km/hr. at an altitude of 7km. The speed at which the bomb will strike the earth would be
What is Load sharing of Transformer ?
how is working bearing heater?
what are the difference between AC lamp and DC lamp
Why single phase induction motors are not self starting ?
1. A 380 / 220 V r.m.s. 3-phase 4-wire circuit carries loads of 8 + j8.1 ohm; 4 + j4.1 ohm; and 2 +j2.1 ohmin the three phases respectively. The length of the circuit is 100 m, and the resistivity of the phase conductors is 0.0005 Ω/m. The neutral conductor is of the same size as the phase conductors. a) Select a reference angle 0for the first phase. Then write down the three phase voltages in both polar format and complex number format. b) Make appropriate assumptions, and take temperature effects on resistance is insignificant. Calculate the currents in the three phases. (Note: Determine conductor resistance, and apply Kirchhoff’s Voltage Law) Based on the result, suggest a main switch rating for the circuit. c) Show your preferred direction of neutral current in a diagram, and then determine its value. (Note: Apply superposition principle, and Kirchhoff’s Current Law) Use its magnitude to show that in this circuit, the unbalanced load may increase the voltage drop in some of the phases. (Note: Also observe the common volt drip in neutral) State your assumptions, if there are any. d) Suddenly the neutral wire of the circuit is broken. Estimate the new currents in the first phase, i.e. Phase L1. State your assumptions, if there are any.
how can service sitting be setted for MCCB?Example for sittings IR (CURRENT RATING),IS(CURRENT STARTING)IO (current operating)?
how maney type tempereture measurement ?
