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How many times of the line current of squirrel cage three-phase asynchronous motor when it is star connected is that when it is triangle connected?
The line current of triangle is three times of that of star, and the phase current of triangle is three times of that of star
Star delta step down starting control of three phase asynchronous motor
1. Draw the relay - controller control circuit, explain the working principle
2. Draw I / O wiring diagram controlled by PLC
3. Draw ladder diagram controlled by PLC
And
RELATED INFORMATIONS
- 1. The purpose of star delta Depressurization So the line current is a fixed value. The star phase current is equal to the line current, which is the value. The △ phase current is one third of this value. So the △ phase current is smaller
- 2. University electrician! Under the condition of constant power supply voltage, if the triangle connection of the motor is wrongly connected into a star connection, or vice versa, what are the consequences?
- 3. The power frequency AC voltage of 220 V and 380 V in engineering refers to its maximum value (a), instantaneous value (b), average value (c) and effective value (d)
- 4. Is 380V AC contactor coil 380V?
- 5. The internal resistance of an electric fan is 20 Ω. After connecting with the voltage of 220 V, the electric power consumed during normal operation is 66 W (1) What is the current passing through the electric fan motor during normal operation? (2) what is the power converted into mechanical energy and internal energy when the electric fan is working? What is the efficiency of the motor at this time? (3) if the electric fan blade is stuck and cannot rotate after the power is connected, how much is the current passing through the motor? How much is the electric power and heating power consumed by the motor?
- 6. Why is the voltage at both ends of each branch equal to the supply voltage in parallel circuit?
- 7. Characteristics of series circuit voltage expression characteristics of parallel circuit voltage expression——
- 8. Characteristics of series and parallel current and voltage
- 9. The law of voltage in series circuit and parallel circuit,
- 10. What is the law of series circuit voltage?
- 11. The three voltages of one equipment are 380V, the load current of the main switch is 160A, the rated capacity of the equipment is 65kva, and the power factor is about 0.95 The three voltage of a device is 380V, the main switch of load current is 160A, the rated capacity of the device is 65kva, and the power factor is about 0.95, Can this 160A be used as the total current?
- 12. There is a small bulb of ammeter and voltmeter in series circuit Among them, the voltmeter measures the normal light of the small bulb The position of ammeter bulb is changed Write down what's going to happen next
- 13. Xiaohong and Xiaowei have done the experiment of "measuring the electric power of small light bulb". There are two kinds of power supply (voltage is 6V), voltmeter, ammeter and sliding rheostat (a is marked with "50 Ω & nbsp; & nbsp; 2A", B is marked with "20 Ω & nbsp; & nbsp; It is known that the rated voltage of the two small lamps are 2.5 V and 3.5 V respectively, and the rated current is the same. They choose the equipment to carry out the experiment. Xiaohong connects the circuit correctly, connects a small lamp into the circuit, closes the key, moves the slide of the rheostat, and observes that the small lamp lights normally when the slide is near the midpoint. The ammeter shows the following As shown in the figure. ① during the experiment, the rheostat selected by Xiao Hong is______ (choose "a" or "B"), the rated voltage of the lamp she measured is______ V, rated current of______ Please calculate the rated power of Xiaohong and Xiaowei according to the relevant information______ (write the calculation process)
- 14. When measuring the electric power of small bulb, considering that the ammeter and voltmeter have certain resistance, should the measured value of electric power of small bulb be larger than the real value
- 15. The ammeter is out of order. There is a voltmeter. How to measure the rated power of the bulb
- 16. In the series circuit, a bulb short circuit or open circuit, how does the voltmeter and ammeter change, and in the parallel circuit, how does the ammeter and the voltmeter change
- 17. What is open circuit, short circuit, open circuit? How to know whether the bulb is short circuit or open circuit? What about the series connection of voltmeter? What about the parallel connection of ammeter? It's junior high school science knowledge
- 18. If the light bulb is short circuited, does the voltmeter and ammeter show the number?
- 19. The voltage at both ends of the small bulb is 3.8V, and the current passing through is 0.3A. Within 10min, the current does work on -- J and consumes -- J's electric energy To get the formula, the process
- 20. How much resistance does it take to connect 1 LED (light emitting diode) in series with 24 V voltage