Anhui Hetuo Electrical Equipment Co., Ltd.-Electric-Compensation Cabinet-Switchgear

Ats Dual Power Switch Cabinet High And Low Voltage Power Distribution Cabinet

　　Power distribution equipment is a general term for high-voltage power distribution cabinets, generators, transformers, power lines, circuit breakers, low-voltage switch cabinets, power distribution boards, switch boxes, control boxes and other equipment in the power system. 　　The importance of electrical equipment maintenance: 　　Second, electricity regulations clearly require regular maintenance of equipment. The relevant requirements of power supply laws and regulations Q/CSG 1 0007-2004 "Power Equipment Preventive Test Regulations" stipulates the relevant requirements of various power equipment preventive tests to determine whether the equipment meets the operating conditions, prevent equipment damage, and ensure safety. run. The importance of electrical equipment maintenance 　　The main functions of the electrical control system (1) Monitoring function. Mainly refers to that the electrical control system can closely monitor the power consumption system of the high and low voltage power distribution plant including the generator and transformer working group system, and the current status of the high voltage DC system, the electrical office system and the electrical equipment switches controlled by it. The status is monitored, and the past status is recorded and memorized. Once a danger occurs, the isolation switch can be cut off and controlled accordingly to achieve the purpose of protecting the safety of personnel and ensuring the perfection of the equipment.

20 Questions And Answers About Common Knowledge In The Electrical Industry, Check For Omissions

　　1. How many kinds of reactive power sources are in the power system? 　　The reactive power sources in the power system include: 　　1. Synchronous generator 　　2. Adjust the camera 　　3. Parallel compensation capacitor 　　4. Series compensation capacitor 　　5. Static compensator 　　2. What is the purpose of the current transformer? 　　The current transformer converts the large current into a small current according to a certain proportion, provides the current for the use of various meters and relay protection, and isolates the secondary system from the high voltage. It not only guarantees the safety of people and equipment, but also simplifies and standardizes the manufacture of meters and relays, and improves economic benefits. 　　3. Why install a set of lightning arresters between the power capacitor and its circuit breaker? 　　The installation of lightning arrester can prevent the operation overvoltage that may occur during the pulling and closing operation of the power capacitor, and ensure the operation of electrical equipment. 　　4. What are the wiring methods for current transformers? 　　There are two current transformers, two-phase V-shaped wiring and two-phase current difference wiring; there are three-phase Y-shaped wiring, three-phase delta wiring and zero sequence wiring that use three current transformers. 　　5. Why must the secondary side of the voltage transformer and current transformer be grounded? 　　The secondary side grounding of the voltage transformer and current transformer is a protective grounding. If the primary, secondary, and secondary side insulation is damaged, the primary side high voltage will be connected to the secondary side, which will threaten people and equipment, so the secondary side must be grounded. 　　6. What is the function of parallel reactor and series reactor? 　　The line shunt reactor can compensate the capacitive charging current of the line, limit the rise of the system voltage and the generation of operating overvoltage, and ensure the reliable operation of the line. 　　The busbar series reactor can limit the short-circuit current and maintain a high residual voltage of the busbar. The series reactor of the capacitor bank can limit the higher harmonics and reduce the reactance. 　　7. What are the characteristics of the single-bus section wiring method? 　　Single busbar segmented wiring can reduce the influence range of busbar faults and improve the reliability of power supply. When a section of the bus has a fault, the section circuit breaker will automatically trip under the cooperation of the relay protection to remove the fault, so that the non-faulty bus maintains normal power supply. For important users, power can be obtained from different sections to ensure uninterrupted power supply. 　　8. What are the disadvantages of double bus wiring? 　　The double bus has the following disadvantages: 　　1. Wiring and operation are relatively complicated, and misoperation is prone to occur during switching operation 　　2. There are many bus isolation switches, and the structure of the power distribution device is more complicated, so the economy is poor 　　9. What is the compensation degree of the arc suppression coil and what is the residual current? 　　The ratio of the difference between the inductance current and the capacitance current of the arc suppression coil and the capacitance current of the power grid is called the compensation degree. After the inductance current of the arc suppression coil compensates for the capacitive current, the residual current flowing through the grounding point is called residual current. 　　10. When the system whose neutral point is grounded through the arc suppression coil is operating normally, does the arc suppression coil carry voltage? 　　When the system is operating normally, due to the unbalanced three-phase ground capacitance of the line, there is a certain voltage between the neutral point of the network and the ground, and the magnitude of the voltage value is directly related to the unbalanced capacitance. Under normal conditions, the voltage generated by the neutral point cannot exceed 1.5% of the rated phase voltage. 　　11. Why does the battery self-discharge? 　　The main reason for the self-discharge of the battery is that the pole plates contain impurities, which form a local small battery, and the two poles of the small battery form a short circuit, which causes the battery to self-discharge. In addition, due to the difference in the density of the battery electrolyte from top to bottom, the electromotive force on the top and bottom of the electrode plate is uneven, which will also cause self-discharge of the battery. 　　12. Why should the battery be charged and discharged regularly? 　　Periodic charging and discharging is also called checking charging and discharging. It is to perform a larger charge and discharge reaction on the battery operating on floating charge after a certain period of time to check t

Selection Of Switch For Lighting Circuit Of Elevator Shaft

　　Through an example of a road lighting project in a high-rise residential building, the problems of single-phase short-circuit protection setting and sensitivity verification in the elevator shaft lighting power distribution system are discussed. In the TN-S system, the B-type miniature circuit breaker can be used for the elevator shaft lighting power distribution trunk switch. The lamps should be added with compensation capacitors, and the power factor of the lamps should be greater than 0.9. 　　At present, there are more and more high-rise civil buildings, and high-rise buildings are equipped with elevators. For elevator shaft lighting, the code has clear requirements. Article 9.4.5 of the Civil Building Electrical Design Code (JGJ16-2008) stipulates: lighting should be installed in the elevator shaft, and the illuminance should not be less than 50lx, and the following requirements should be met: ① Install a lamp within 0.5 meters from the high point and the low point of the hoistway. One lamp should be installed at a distance of no more than 7m in the middle, and control switches should be installed in the engine room and the pit; ②The power supply for the top of the bridge and the hoistway. Easy to be 36V; when 220V must be installed, a residual current operated protector should be installed. 　　For the elevator shaft lighting distribution lines of high-rise buildings, most people think that the switches and wires should be selected according to the calculated current. This is generally not a problem for buildings that are not very tall, but for 30-story or higher-rise buildings. For buildings, it is not enough to only consider the overload protection of the line. The characteristics of the lamps, the short-circuit protection of the line, and the voltage loss should also be considered. 　　Project example 　　A 32-story residential building with a height of 3 meters. There is a power distribution room in the basement, and the public power is from two outdoor box transformers (capacity 630KVA, box transformer with 3m long copper bus 3 (80x80) + 1x (63x6.3)), respectively lead one 380/220V power supply to For the power distribution cabinet in the basement, both circuits use ZRYJV22-4x150mm2 cables, and the line m1 is 50m long. 　　After being distributed by the power distribution cabinet, they are led to the fan and emergency lighting. For emergency lighting lines, trunk type + radiation type power supply is used, two trunk lines use NHYJV cables, the specification is 4x35+1x16mm2, the line m2 is 100m long, each four floors is equipped with an emergency dual power switch box, and the roof computer room lighting is separately equipped with a pair of power switch boxes , Adopt the main line T connection to connect with the power supply main line. 　　The dual power switch box circuit of the roof machine room includes elevator shaft lighting, machine room lighting, machine room sockets, elevator shaft sockets, aviation obstruction lights and other circuits. The elevator shaft lighting circuit uses 220/36V (capacity 500VA) transformers to supply power. One lamp is installed within 0.5 meters of the low point, with an odd-numbered layer in the middle, a total of 18 lamps. The lighting adopts Philips compact energy-saving lamps, the power is 13W, the luminous flux is 900, the power factor after compensation is 0.9, and the lighting power distribution uses two BV10mm2 wires. The line m3 is 96m long. 　　The protection of the elevator shaft lighting distribution circuit should have overload protection, short circuit protection, and should avoid the starting current of the lamps. 　　When a short circuit occurs at the end of the line of this project, there are seven impedance components in the loop, including high-voltage system, 10/0.4kV transformer, low-voltage bus, low-voltage cable m1, low-voltage cable m2, 220/36V transformer, and low-voltage wire m3. According to the data in Tables 4-22~25 on pages 155~159 of the "Industrial and Building Power Distribution Design Manual" Third Edition, the impedance of the single-phase L-N circuit of each component can be calculated, and then the short-circuit current can be calculated. After calculation, the short-circuit current is, Id=105.2A. 　　The protection of the elevator shaft lighting distribution circuit should meet the following requirements: 　　1) The setting current of the long-time delay release of the low-voltage circuit breaker for lighting should be greater than the calculated current of the circuit. , 　　2) The setting current of the instantaneous overcurrent release of the low-voltage circuit breaker for lighting should be 4~7 times greater than the calculated current of the circuit. 　　3) In order to ensure the sensitivity of the circuit breaker, the setting current of the instantaneous overcurrent release of the circuit breaker should be less than 1/1.3 times of the small short-circuit current at the end of the line. 　　For this project (18 sets of lamps), th