(a) An electrodynamic wattmeter is used to measure the electrical power in a circuit. The diagram in Figure Q3(a) depicts the symbol for the two types of coils in the wattmeter. M L COM Ww. Figure Q3(a) Name the two coils and explain the reason for the number of turns to be low or high for each coil, respectively. (b) An electrodynamometer-type wattmeter has a current coil resistance, ZRc= 0.5 0. Calculate the percentage error of the wattmeter reading if the moving coil is connected before the current coil for a single-phase circuit. The load is specified as 220 V with unity power factor. Let the load current, I, = 88 I, = 88 + 10 = 98A. (e) An energy meter has a constant of 60 revolutions per kilowatt-hour (kWh). Calculate the number of revolutions made by the disc in 30 minutes when measuring the energy consumed by a single-phase load carrying the same current as the I, value set in part Q3(b) above at 230V and power factor of 0.5. Express your final answer to the nearest integer.

(a) An electrodynamic wattmeter is used to measure the electrical power in a circuit. The diagram in Figure Q3(a) depicts the symbol for the two types of coils in the wattmeter. M L COM Ww. Figure Q3(a) Name the two coils and explain the reason for the number of turns to be low or high for each coil, respectively. (b) An electrodynamometer-type wattmeter has a current coil resistance, ZRc= 0.5 0. Calculate the percentage error of the wattmeter reading if the moving coil is connected before the current coil for a single-phase circuit. The load is specified as 220 V with unity power factor. Let the load current, I, = 88 I, = 88 + 10 = 98A. (e) An energy meter has a constant of 60 revolutions per kilowatt-hour (kWh). Calculate the number of revolutions made by the disc in 30 minutes when measuring the energy consumed by a single-phase load carrying the same current as the I, value set in part Q3(b) above at 230V and power factor of 0.5. Express your final answer to the nearest integer.

Electricity for Refrigeration, Heating, and Air Conditioning (MindTap Course List)

10th Edition

ISBN:9781337399128

Author:Russell E. Smith

Publisher:Russell E. Smith

Chapter17: Commercial And Industrial Air-conditioning Control Systems

Section: Chapter Questions

Problem 6RQ

See similar textbooks

Similar questions

Briefly explain the working of following power plants a) Thermal Power plant b) Hydel power plant
1. A resistor, in series with a 138-microfarad capacitor, is connected to a 60-cycle source. If the voltage drop across the capacitor is 115 volts and the power taken by the circuit is 922 watts, calculate (a) the circuit current, (b) the ohmic value of the resistor, (c) the line voltage, (d) the circuit power factor. Please show complete solution and the circuit diagram. Please round off answers up to the 3rd decimal place. Thank you!
DEGREE: ELECTRICAL ENGINEERING SUBJECT/COURSE: AC CIRCUITS NOTE: Please solve in this way. 1. Please have a good handwriting, some of the answers are not readable. Thank you! 2. GIVEN.(include symbols and units) 3. REQUIRED/FIND/MISSING (with symbol/s) 4. ILLUSTRATION (Required). 5. STEP-by-STEP SOLUTION with Formulas and Symbols. No Shortcut, No skipping, and detailed as possible 6. FINAL ANSWERS must be rounded up to three decimal places • If Vab = 480V in a balanced Y-connected three-phase generator, find the phase voltages, assuming the phase sequence is a. abc, b. acb
(a) Is a wattmeter required to measure the real power delivered to a resistive load? (b) A wattmeter will indicate zero when the current lags (or leads) the voltage by 90 0 . (c) An incandescent lamp, rated at 100 W, gives a certain amount of light when placed across the 120 V ac power line. Would the amount of light increase, decrease or remain the same, when the lamp is placed across a 120 V dc power line? Explain your answer.
The data for a wind turbine is given below: Wind speed = 14 meters/sec, Length of blade = 10 meter Refer to the above wind turbine choose the correct statement a. The wind rotor swept area is 40square meters. b. The wind rotor swept area is 314 square meters. c. The wind rotor swept area is 31.4 square meters. d. The wind rotor swept area is 62.4 square meters.
What are some of the environmental impacts of the use of geothermal energy sources? Compare these with present power generating schemes? (150 words)
Question No. 11: Sketch the layout of hydroelectric power plant and explain the functions of each component in it. Discuss the advantages and limitations of this plant.
A string of suspension consists of four (4) units. The Voltage between each pin and earth is 0.12 of the Self-Capacitance of the unit. The Voltage between the Line Conductor and earth is 135KV. Find the Voltage distribution across each unit and the String Efficiency
Question 1:a) State why voltage control and cable stranding are necessary in powersystemsb) Briefly explain where and how the following state variables ofa power supply grid are controlled.i) Frequencyii) Active powerili) Reactive poweriv Voltage.
DEGREE: ELECTRICAL ENGINEERING SUBJECT/COURSE: AC CIRCUITS NOTE: Please solve in this way. 1. Please have a good handwriting, some of the answers are not readable. Thank you! 2. GIVEN.(include symbols and units) 3. REQUIRED/FIND/MISSING (with symbol/s) 4. ILLUSTRATION (Required). 5. STEP-by-STEP SOLUTION with Formulas and Symbols. No Shortcut, No skipping, and detailed as possible 6. FINAL ANSWERS must be rounded up to three decimal places PROBLEM: • A positive-sequence balanced three-phase wye-connected source with a phase voltage of 120 V supplies power to balanced wye-connected load. The per phase load impedance is 40+j10Ω. Determine the line currents in the circuit if <Van=0°.
1. Incremental cost fuel cost is GHC per megawatt hour for two units in a plant are given by dF1dP1=0.1P1 + 20 dF2dP2=0.12P2 + 16 The minimum and maximum load on each unit is to be 20 MW and 125MW respectively. Determine the incremental fuel cost and the allocation loads between units for this minimum cost when loads are i) 100MW ii) 150MW . Assume both units are operating.
Solve for the nodal voltages and the power consumed by the passive elements.