There is the connection scheme of a residual current device (RCD). The principle of operation: Under normal conditions, the current from L to N flows through the coils of RCD. The net magnetic flux in the circular core is zero, which results no current in the sensing coil. If any fault bypasses the coils, then the net magnetic flux is nonzero and a current is induced in the sensing coil. This makes the relay opens the switch. Let the source be 220V and the current through the load be 1 A. At some time, the test button becomes on and a current of 25 mA flows through the test button. i) Find the resistance through the test button and the load. ii) Does RCD opens the circuit if it operates for a differential current lager than 30 mA? Note: Assume that the coils on the circular core has zero resistance

There is the connection scheme of a residual current device (RCD). The principle of operation: Under normal conditions, the current from L to N flows through the coils of RCD. The net magnetic flux in the circular core is zero, which results no current in the sensing coil. If any fault bypasses the coils, then the net magnetic flux is nonzero and a current is induced in the sensing coil. This makes the relay opens the switch. Let the source be 220V and the current through the load be 1 A. At some time, the test button becomes on and a current of 25 mA flows through the test button. i) Find the resistance through the test button and the load. ii) Does RCD opens the circuit if it operates for a differential current lager than 30 mA? Note: Assume that the coils on the circular core has zero resistance

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter12: Power System Controls

Section: Chapter Questions

Problem 12.4P

See similar textbooks

Similar questions

What is use of solenoid coil in the pressure to converter? a. To produce magnetic field in the LVDT b. To change the LVDT output c. To bring back the pivoted beam normal position d. To produce linear displacement in bellows
State the Method of connection of different field coils. ( In DC Machines )
help me in these questions pls write the questions with the and by (Computer) 1-Which of the following statements INCORRECTLY explain the label in the figure about LVDT working principles? a. Secondary coils are connected in series in such a way that their output is opposing each other. b. Constant DC voltage input to primary coil. c. Displacement moves ferrous rod from central position. d. The difference of the output voltage between the two secondary voltage.==========2- Explain the working principle of the measurement system in the figure below.i. Force input that is supplied to the sensor is processed to give the response in the form of raw output signal.ii. Signal conditioner manipulated the weak signal to give a conditioned input.iii. Analog or digital indicator display the unit that gives output reading of quantity being measured.iv. Measured value is compared with the input value for further action. a. ii, iii and iv only. b. i, ii and iv only. c. i, ii and…
For 4 pole d.c machine armature winding with a double layer progressive simplex wave winding with 23 number of slots answer the following: a How many coils are present? b What is the coil span in terms of number of slots? c What is commutator pitch in terms of commutator segments? d How many coils are there between two consecutive commutator segments? e How many parallel paths are present?
Q- Select the correct answer: a- The high concentration of holes and electrons in the central junction of a thyristor decreases by the process of ................ during off transient period with a time tar. 1- Forced commutation, 2- Phase commutation, 3- Load commutation, 4- Reverse bias commutation, 5- None of previous. Power Electronics b- The non-trigger voltage of a thyristor is.............. 1- VBO, 2- VBn, 3- VGn, 4- VGD, 5- None of previous. is the limiting positive anode voltage above which thyristor may be damage. 1- PRV, 2- PFV, 3- PAV, 4- PAK, 5- None of previous. C- d- The ripple frequency in the output voltage of single-phase half-controlled bridge AC/DC converter is when a > 60°. 1- 3f, 2-6f, 3- 2f, 4- f, 5- None of previous. ********* e- The integrator in the firing circuit of 1-phase bridge AC/DC converter is necessary to have firing angle range. 1-0-90°, 2-0-120°, 3-0-180°, 4-0-360°, 5- None of previous. f The harmonic contents in an inverter can be reduced through…
Permanent Magnet Moving Coil (PMMC) meters can be used for both AC and DC measurements. O a. TRUE O b. FALSE
Untitled Section Jalis 6 In d.c. generators armature reaction is produced by field current O armature current commutating winding current none of the mentioned compensating winding current *.The use of d.c. generators eliminated the use of rectifiers and ac supplies True False O
the armature mmf can be -2 reduced by reluctance of the magnetic the circuit in the region of the pole .tip a) Increasing, O b) decreasing O c) don't put O
A commutator has 456 segments. Indicate whether or not the windings are possible a. Duplex-wave, eight poles b. Simplex-wave, 10 poles
The function of Copper shading band in induction type energy meter is to ensure flux produced by potential coil is exactly in quadrature with supply voltage. Select one: O True False
In 2-pole machines: the wave winding have greater generated voltage than *.the lap winding armatures True False *.For high rotating speed machines the number of poles must be Little True False The reactance voltage is added in the coil undergoing commutation to * reduce the spark True False
Choose the right answer. 1. The basic elements in any power system are 2. The reactors have the following problems 3. If a fault occurred between phases (A, B, and C) simultaneously the fault is called if the fault occurred on phase (A) only or phases (A, B), it may take the following types and ...... where or 4. The symmetrical component method is 5. Conditions for succesful operation of a power system are 6. The reason we use the numerical methods in load flow analysis is 7. The main diagonal of Y-bus numbers by a factor / not any) 8. The properties of the fault currents and (changes the signs / keeps the signs / multiplies the .... .... ....... re