In daily electric machine management, the most common is our electric motor. The electric motor is the prime mover of the machine. If something goes wrong, it is a big problem. It is the most important part of the company's machine management, so Dalan Motor is small. Prepare to talk with everyone about the necessary knowledge of hydraulic motor operation and maintenance.
1. The generator stator voltage shall not be greater than (110%) of the rated voltage, and the minimum voltage shall not be less than (90%) of the rated voltage, and shall meet the requirements of the (plant) voltage.
2. The normal operation frequency of the generator should be kept at (50) Hz, the allowed variation range is (±0.2) Hz, and it can be operated continuously according to rated capacity. When the frequency changes, the stator current, excitation current and temperature of each part must not exceed (rated value).
3. The stator voltage of the generator is allowed to change within the rated value range (±5%). When the power factor is rated, the rated capacity does not change. That is, when the stator voltage changes within this range, the stator current may change proportionally. . However, when the generator voltage is lower than the rated value (95%;), the long-term allowable value of the stator current must not exceed the rated value (105%.).
4. The hydrogen purity of the generator operation shall not be less than (96%) and the oxygen content shall be less than (2%).
5. The rated power factor of the generator is (0.85). For generators that have not been tested in phase, the power factor is allowed to run for a long time in the late phase (0.95 to 1) when the excitation regulator device is put into automatic operation; when there is a change in the power factor, the presence or absence of the power factor should be enabled. The power does not exceed the (PQ) output curve at the time of hydrogen pressure.
6. The rate of increase of active load after paralleling of generators is determined by (vehicle) and the rate of increase of reactive load (unlimited), but the change in stator voltage should be monitored.
7. The generator rotor winding insulation resistance is measured with a (500V) rocker. The insulation value shall not be less than (0.5MΩ).
8. When the stator three-phase current is unbalanced, (negative sequence) current will be generated.
9. During the boosting process, the generator shall check that the stator three-phase voltage should rise (steady) and the rotor current should not exceed (no-load value).
10. The 6KV motor measurement insulation shall be measured with a (2500 V) megger and the measured insulation resistance shall be greater than (6) MΩ.
11. Under normal conditions, the squirrel-cage rotor motor is allowed to start in cold state (2 times), and each time interval is not less than (5) minutes, allowed to start in the hot state (1), only in the accident Motors that do not process or start more than (2 to 3) seconds can be started more than once.
12. The insulation resistance of 6KV high-voltage factory motor is measured under the same environment and temperature. If this measurement is lower than (1/3 to 1/5) times of the previous measurement value, the reason should be checked and must be measured. Absorption ratio "R60/R15", this value should be greater than (1.3).
13. The motor can be operated at nominal voltage and within ±1% of the supply frequency, and its rated output does not change.
14. The main transformer (full stop) allows operation at the lower rated load. If the load is small, the upper oil temperature of the main transformer does not reach the specified value, it is allowed to rise to the specified value, but the maximum operating time of the main transformer must not exceed (60) )minute.
15. The three-phase unbalance current of the three-phase AC motor must not exceed the rated value (10%), and any one phase current must not exceed (rated value).
16. For transformers with oil-immersed air-cooled and oil-immersed air-cooled modes, the allowable maximum temperature of the upper layer oil shall not exceed (95)°C, and generally it shall not exceed (85)°C.
17. When the gas protection secondary circuit is grounded at one point, the heavy gas protection should be switched to the (signal) position.
18. The upper oil temperature of the forced-oil circulating air-cooled transformer is generally not to exceed (75)°C and the maximum is not to exceed (85)°C.
19. The primary voltage applied to the transformer shall not exceed (105%) the rated value of the tap, and the secondary side of the transformer may have a rated current.
20. The general power plant adopts double busbar connection. In normal operation, it is necessary to ensure that there is one component (grounding) on ​​each item line. The main transformer is generally grounded (grounding switch) and the neutral point is usually (directly) grounded.
21. 6KV switchgears are equipped with "five-prevention" mechanical locking devices. Generally, the locking function of the forced mechanical locking device is (when the car switch is in the closing state, it cannot move), (the grounding switch is in the closing state, the car The switch can not be pushed into the working position), (the switch can not close the grounding switch when it is in the working position), (the grounding switch does not cooperate, and the tailgate of the switch cabinet cannot be opened).
22. After all isolating switches are closed, it must be checked that the three-phase contacts are in good contact.
23. Before closing the grounding switch, it must be known that the power switch on each side is in (disconnected) position and is performed after verification (without voltage).
24. If a load broaching brake occurs, it should be quickly (closed) before breaking the arc. If it has been broken, it is forbidden to close it again. If a load closing occurs, it is forbidden to restart (disconnect).
25. In the absence of a switch in the loop, an isolation switch can be used to perform a loop equalization current with a pull-in voltage not exceeding 10 kV and a current below (70A).
26. The normal operating voltage of the cable line should not exceed 15% of the rated voltage of the cable.
27. Under normal circumstances, electrical equipment is not allowed (unprotected) to operate, partial protection may be deactivated if necessary, but (primary protection) is not allowed to be deactivated at the same time; it is forbidden to open the protective device door during operation, and it is forbidden to follow the control room. Bao Xiao indoor use (wireless) communications equipment.
28. Measure the insulation resistance with a (500)V megger for AC and DC low voltage factory motors below 380V. The insulation resistance of the motor must not be lower than (0.5) MΩ.
29. The generator time-limited overload protection reflects the size of the generator (stator current).
30. The overvoltage protection of the stator windings of the generator reflects the magnitude of the (terminal voltage).
31. Generator timing negative sequence overcurrent protection reflects the size of the generator stator (negative sequence current) to prevent overheating of the generator (rotor surface).
32. The four limiting factors on the PQ curve of the generator are (heating of the stator windings, heating of the rotor windings, heating of the iron core at the ends of the stator, stable operating limits).
33. Generator reverse power protection for protection (turbine).
34. Install the grounding wire in the order of (ground) and rear (conductor).
35. Electrical insulating materials are classified according to the maximum work (temperature) allowed in normal operating mode.
36. The current value indicated by the alternating current meter represents the (effective) value of the current.
37. The safety distance for equipment without power failure is specified as (0.7)m for 6kV, (1.5)m for 110KV, and (5)m for 500KV.
38. In the power plant, the phase sequence of the three-phase bus is represented by a fixed color. The specified (yellow), (green), and (red) indicate the A, B, and C phases, respectively.
39. The equipment-to-ground voltage below the (250) volts is a low-voltage equipment, so we often say that the 380V plant power system is (low-voltage equipment).
40. When the generator is in normal operation, the stator current three-phase unbalanced value generally cannot exceed the stator rated value (10%).
41. Phase difference dynamic high frequency protection uses a (high frequency) signal to compare the current (phase) across the protected line.
42. When the disconnector is found to be hot, the equipment (load) should be reduced until no heat is generated, and the ventilation and cooling at the location should be strengthened. If the heat is severe, the equipment should be operated and then processed.
43. When the temperature difference between the highest and lowest temperatures between the stator coils of water-cooled generators reaches (8)°C or the temperature difference between the outlets of the stator bars and the lead pipes reaches (8)°C, the alarm should be reported and the cause identified. Reduced load) processing.
44. The temperature difference between the stator bars of the water-cooled generator reaches (14)°C or the temperature difference between the outlet pipe of the stator reaches (12)°C, or the temperature of the inter-layer temperature measuring element exceeds (90)°C or the outlet water temperature exceeds any of the stator slots ( 85) At the temperature of °C, after confirming that the temperature measuring element is correct, in order to avoid a major accident, (reverse flushing) and related inspections shall be performed immediately (stopped).
45. The product of the rms value of the total voltage in a sinusoidal AC circuit and the effective value of the current includes both (active power) and (reactive power), which we call (apparent power).
46. ​​In the circuit, the current flowing into the node (equal to) is the current flowing from that node, which is Kirchhoff's law.
47. Starting from any point in the loop, circulating one cycle along the loop, the sum of potential rise and (equal) potential reduction, which is Kirchhoff (second law).
48. In the various methods of calculating complex circuits, the (branch current) method is the most basic method.
49. In (inductive) circuits, the voltage leads the current; in the (capacitive) circuit, the voltage lags behind the current.
50. In power systems, shunt reactors are commonly used to absorb excess (reactive) power and reduce (system voltage).
51. In a three-phase AC circuit, a delta-connected power supply or load, their line voltage (equal to) the phase voltage.
52. The total power of a symmetrical three-phase AC circuit is equal to (3) times the single-phase power.
53. For a symmetrical three-phase AC circuit, the neutral voltage is equal to (zero).
54. In power systems, short circuit means an abnormal connection between (phase and phase) or (phase to ground) through an arc or other relatively small impedance.
55. A storage battery is a type of energy storage device that converts (electrical) energy into (chemical) energy. When used, it converts (chemical) energy into (electrical energy) and releases it through external circuits.
56. The size of the conductor resistance is not only related to the (length) and (cross-sectional area) of the conductor, but also related to the (material) and temperature of the conductor.
57. In a closed circuit, the voltage is the condition that produces the current. The size of the current is related to the size of the circuit (resistance) and to the size of the (terminal voltage).
58. In a series circuit, the voltage distribution across the load is proportional to the size of each load resistor; in a parallel circuit, the current distribution of each branch is inversely proportional to the resistance of each branch.
59. When the (current) in the coil changes, a (self-inductance) electromotive force is generated at both ends of the coil.
60. After the conductor is energized, the direction of the electromagnetic force received in the magnetic field is determined by (left-hand rule), and when the conductor is in the magnetic field to cut the magnetic force line of motion, the direction of the induced electromotive force is determined by (right-hand rule).
61. The number of periodic changes in alternating current per second is called (frequency), denoted by the letter (f), the unit name is (Hertz), and the unit symbol is expressed in (Hz).
62. The maximum instantaneous value of a sinusoidal alternating current in a cycle is called the (maximum) value of alternating current, also called (amplitude) or (peak).
63. The maximum dry value of AC, such as the effective value, is divided by (√2).
64. In circuits composed of resistors, inductors, and capacitors, only (resistive) components consume power, while (inductive) components and (capacitive) components exchange energy and do not consume power.
65. The star-connected power supply, which is not derived at the neutral point, is a (three-phase, three-wire) system. Its current relationship is that the line current is equal to (phase current).
66. The greater the current through a coil, the stronger (magnetic field) is generated and the more (magnetic) lines pass through the coil.
67. A current-carrying coil can generate a magnetic field, and its strength (or strength) is proportional to the current passing through the current-carrying conductor.
68. The voltage between the three-phase terminals is called (line voltage); the voltage between the terminal and neutral is (phase voltage); in a star-connected symmetrical circuit, the line voltage is equal to (√3) times the phase. Voltage.
69. The main cause of a short circuit in the power system is the destruction of the (insulation) current-carrying part of the electrical equipment.
70. The hazards of short-circuits to electrical equipment are: (1) The current (thermal effect) causes the equipment to burn or damage the insulation; (2) (Electrical power) causes the electrical equipment to be deformed and destroyed.
71. Electrical equipment and current-carrying conductors must have adequate (mechanical) strength, be able to withstand the effects of electrodynamic forces in the event of a short circuit, and have adequate thermal (stability).
72. The transformer is based on the principle of (electromagnetic induction), which changes the voltage and current of an alternating current into the same (frequency) but different (numerical) voltages and currents.
73. The principle of an induction motor is to generate a (rotating) magnetic field when a three-phase symmetrical three-phase alternating current flows through a winding. The magnetic field lines of the magnetic field induce (current) the wire on the rotor. Because of the interaction between the stator magnetic field and the rotor current, Generate electromagnetic (torque) and rotate it.
74. Both copper wire and aluminum wire are connected by a conversion joint. If they are directly connected, copper (co) and aluminum wire (a potential difference) exist between them. If moisture is present at the joint, moisture will form (ionization) and electric corrosion will occur.
75. In the vicinity of the transmission line, if an insulator is placed, (inductive) charge is generated. This phenomenon is called (electrostatic) induction of the transmission line.
76. Sulphur hexafluoride (SF6) is a (colorless), (odorless) non-combustible gas and its performance is very stable.
77. Batteries are used as (control) and (protected) DC power supplies in power plants, with the advantages of stable voltage and reliable power supply.
78. The active material on the (positive) plate of the battery is lead dioxide, and the active material on the (negative) plate is spongy lead.
79. A group of batteries has a capacity of 1200 AH. If discharged at a current of 100 A, the continuous supply time is (12 hours).
----- Editor: Dalan Oil Pump Motor 02 - Procurement Consultant
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Power Meter is a monitoring and testing instrument which determines the power consumption of a connected appliance and the cost of the electricity consumed.
Built-in 3.6V rechargeable Batteries ( . The purpose of the batteries is to store the total electricity and memory setting
Resetting
If an abnormal display appears or the buttons produce no response, the instrument must be reset. To do this,
press the RESET button.
Display Mode
Entire LCD can be displayed for about 1 minute and then it automatically gets into Model. To transfer from
one mode to the other, press the FUNCTION button.
Mode 1: Time/Watt/Cost Display Display duration(how long) this device connect to power source.LCD on first line shows 0:00 with first two figures mean minutes(2 figures will occur while occur at 10 min) and the rest shows seconds. After 60mins, it displays 0:00 again with first two numbers meas hour(2 figures will occur at 10hours)and the rest shows minutes. The rest can be done in the same manner which means after 24 hours, it will re-caculate. LCD on second line displays current power which ranges in 0.0W 〜 9999W. LCD on third line displays the current electricity costs which ranges in O.Ocost 〜 9999cost. It will keep on O.OOcost before setting rate without other figures.
Mode 2: Time/Cumulative electrical quantity Display Display duration(how long) this device connect to power source.
LCD on first line shows 0:00 with first two figures mean minutes(2 figures will occur while occur at 10 min) and the rest shows seconds. After 60mins, it displays 0:00 again with first two numbers meas hour(2 figures will occur at 10hours)and the rest shows minutes. The rest can be done in the same manner which
means after 24 hours, it will re-caculate. LCD on second line displays current cumulative electrical quantity which ranges in 0.000KWH 〜 9999KWH without other figures. LCD on third line displays"DAY"- "1 'Will be showed on numerical part(the other three figures will be showed at carry) which means it has cumulated electrical quantity for 24hours(one day). The rest can be done in the same manner untill the maximal cumulative time of 9999 days.
Mode 3: TimeA^bltage/Frequency Display LCD on first line displays the same as Mode 1 dones. LCD on second line displays current voltage supply (v) which ranges in 0.0V 〜 9999V .LCD on third line displays current frequency (HZ) which ranges in 0.0HZ 〜 9999Hz without other figures.
Mode 4: Time/Current/Power Factor Display LCD on first line displays the same as Mode 1 dones.LCD on second line displays load current which ranges in 0.0000A 〜 9999A. LCD on third line displays current power factor which ranges in 0.00PF 〜 LOOPF without other figures.
Mode 5:Time/Minimum Power Display LCD on first line displays the same as Mode 1 dones. LCD on
second line displays the minimum power which ranges in 0.0W 〜 9999W. LCD on third line displays character of "Lo" without other figures.
Mode 6: Time/Maximal Power Display LCD on first line displays the same as Mode 1 dones. LCD on second line displays the maximal power which ranges in 0.0W 〜 9999W. LCD on third line displays character of "Hi" without other figures.
Mode 7: Time/Price Display LCD on first line displays the same as Mode 1 dones. LCD on third line displays the cost which ranges in O.OOCOST/KWH 〜 99.99COST/KWH without other figures.
Overload Display: When the power socket connects the load over 3680W, LCD on second line displays the''OVERLOAD[ with booming noise to warn the users,( 1918928,selectable choice)
Supplemental informations:
1: Except [OVERLOAD[ interface, LCD on first line display time in repitition within 24hours.
2: LCD on first line, second line or third line described in this intruction take section according to two black lines on LCD screen. Here it added for clarified purpose.
3. Mode 7 will directly occur while press down button "cost".
4. [UP"&"Down" are in no function under un-setting mode.
Setting Mode
1. Electricity price setting
After keeping COST button pressed lasting more than 3 seconds(LCD on third line display system defaults price, eg O.OOCOST/KWH ),the rendered content begins moving up and down which means that the device
has entered the setting mode. After that, press FUNCTION for swithing , then press "UP"and "DOWN" button again to set value which ranges in OO.OOCOST/KWH 〜 99.99COST/KWH. After setting all above, press COST to return to Mode7 or it will automatically return to Mode7 without any pressing after setting with data storage.
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