Henan Siemens, GCK Henan Luo Xin electrical distribution box

Electrical wiring distribution box is based on the requirements of the switching devices, measuring instruments, protective devices and auxiliary equipment assembly in a closed or semi-closed metal cabinet panel on the web or to form low-voltage power distribution equipment. You can make use of manual or automatic switch on or breaking the circuit during normal operation. With the protection of electrical cut-off circuit or alarm malfunction or normal operation. By measuring instrument can display the running of the various parameters, but also on some of the electrical parameters can be adjusted, for departing from the normal operation prompts or signals. Commonly used in each issue, distribution and substations. Structural use Edit this paragraph structure and distribution cabinet distribution box, distribution boards, power distribution panel, is centrally installed complete installation switches, meters and other equipment. Category commonly used wood metal distribution box two, because the metal distribution box protection level is higher, you still use more metal. Use distribution box use: rational distribution of electric energy, to facilitate the opening and closing operation of the circuit. A higher level of security protection, can directly display circuit conduction state. Easy to manage, when the electrical fault in favor of overhaul. Classification by structural features and usage: (1) fixed panel switchgear, often called the switch board or power distribution panel. It is a kind of masking panel open switchgear, positive protective effect, back and side still touching the live, low degree of protection can only be used for power supply continuity and reliability requirements of low industrial and mining enterprises, as centralized power supply with a transformer room. (2) Protection of formula (ie, enclosed) switchgear, refer to the mounting surface in addition, all other sides are closed up in a low-voltage switchgear. Such a switch cabinet, protection and monitoring control and other electrical components are installed in a steel or enclosure made of insulating material, it can be installed against a wall or away from the wall. You can not add each loop between the cabinet and isolation measures can also be used a grounded metal plate or insulating plate isolation. Usually the main door switch operation with a mechanical interlock. There are also shielded station switchgear (ie the console), the panel is equipped with control, measurement, signal and other electrical appliances. Protective switchgear is mainly used for craft-site power distribution equipment. (3) switch cabinet drawer. Such switch cabinet with sheet steel enclosure, inlet and outlet circuit electrical components are mounted on extractable drawer, constitute a class-powered task to complete functional unit. Between functional units and bus or a cable, use a grounded metal plate or plastic apart, forming the bus, functional units and three regional cable. There isolation between each functional unit. Switch cabinet drawer with high reliability, security and compatibility, is more advanced switchgear, switchgear current production, the majority of switch cabinet drawer. They are suitable for industrial and mining enterprises require high reliability of power supply, high-rise buildings, as centralized control of the distribution center. (4) power, lighting distribution control box. Mostly enclosed vertically. Due to the use of different occasions, shell protection grade is different. They are mainly used as industrial and mining production site of power distribution equipment. Improved Edit this paragraph fault Cause Fault 1. Environmental temperature on low-voltage electrical distribution box failure caused by the impact of the low-voltage electrical appliances, the fuses, AC contactor, residual current protection, capacitors and gauges and other components. These low-voltage electrical appliances according to GB1497 "Low Voltage basic standards" for design and manufacture, and their corresponding provisions under normal operating conditions: maximum ambient air temperature does not exceed 40 ℃; the average ambient air temperature does not exceed 35 ℃ 24h ; lower limit of the ambient air temperature is not lower than -5 ℃ or -25 ℃. Rural power grids of the distribution box in the outdoor run, it not only by direct sunlight to produce high temperature, while running itself will generate heat, so hot in the summer season, temperatures will reach cabinets above 60 ℃, when the temperature much higher than the ambient temperature of the appliances provisions, failure due to the distribution box electrical components due to overheating and thus occur. 2. Caused by a defective product quality in rural power grids in demand was due to the distribution box number, short construction period, distribution boxes for low voltage electrical plant need urgent delivery time and quantity, and thus created a demand for the product quality requirements are not Strict phenomenon, caused some products into operation shortly after the failure. Some models, such as exchanges and contacts soon after closing due to the contactor coil burned out and put into operation in the distribution box, but can not run. 3. Electrical distribution box failure caused by improper selection due to manufacturing capacity for AC contactor chooses not very appropriate for different outlet circuit installed capacity of exchanges and contacts with, and did not take into account a three-phase unbalanced load, without can partially downstream contactor current levels in the normal selection model based on a current level is selected to improve, resulting in exchange of contacts appears burned hot seasons running. 1 improvement program. For the distribution transformer capacity at 100kV · A power distribution box and above, thermal windows in the side wall of the box, it should take into account the installation thermostat relay (JU-3 type or JU-4 ultra-small temperature relay) and a shaft flow fans, electrical control panel is mounted on the side of the left side of the box, so that the inside temperature reaches a certain value (eg 40 ℃) can automatically start the exhaust fan, forced exhaust heat to the cooling box. 2. Use protection circuit prevents power distribution box external circuit failure. Choose smaller smart lack of protection, such as the choice of DA88CM-II phase motor protection module (Shanghai products) installed in the distribution box in order to prevent low-pressure phase electric motor to run and burn. 3. Improve the original wiring distribution box low-voltage capacitor group, the mounting position by the exchanges and contacts on the trailer coupling, into a low-voltage distribution box is connected between the line and meter gauge. To prevent the operation of the capacitor circuit or phase failure occurs when damage to the capacitor, resulting in inaccurate measurement metering device. In addition, capacitor selection model should be BSMJ series of products to ensure quality and reliable components, safe operation. 4. If the new column with a radio rack, in the production of distribution box enclosure, optional 2 mm and stainless steel plate, and appropriately scaled distribution box size (in JP4-100 / 3W type used by the project-based agricultural reform on, in the original box width dimension increased by about 100 mm, that is, change the original 680 mm 780 mm improved power distribution box external dimensions:. 1300 mm × 780 mm × 500 mm), in order to increase each branch between qualifying, electrical safety outlet and tank shell distance, it is a good operation and maintenance electricians and replacement fusible element, but also to the heat. 5. Use energy-saving AC contactor (similar CJ20SI type), and note the AC contactor coil voltage remaining for the selected current device is connected to corresponding terminals, pay attention to correct load matching. When selecting exchanges and contacts, should be used in the insulation rating of A or above grade product, it must ensure that its main circuit contact current rating should be greater than or equal to the load current is controlled lines. Contactor solenoid rated voltage is 380V or 220 V, coil to allow use in a range of 80% to 105% of rated voltage. 6. Residual current device selection. Must be selected in line with GB 6829 "General requirements for residual current operated protective device" standard, and by the China Certification Committee for Electrotechnical certified products. Optional similar LJM (J) series-saving type, and is the low sensitivity of delay protection. Way protection device to comply with national GB13955-2005 "residual current operated protective devices to install and run" standard. Leakage protection breaking time, when the leakage current is rated leakage current, the operation time should not exceed 0.2s. 7. Distribution box into the outlet selection and low voltage cables, select the cable should meet the technical requirements. For example 30kVA, 50kVA distribution transformer box into the line using VV22-35 × 4 cable splitter outlet use the same specification VLV22-35 × 4 cable; 80kVA, 100kVA transformer distribution box into the line were using VV22-50 × 4, VV22-70 × 4 cable splitter outlet are using VLV22-50 × 4, VLV22-70 × 4 cable, the cable crimping copper and aluminum lugs and then bolted with distribution box wiring trailer coupling . 8. Fuse (RT, NT type) selection. The total distribution transformer low-voltage side overcurrent protection fuse rated current, should be greater than the low-pressure side of the distribution transformer rated current, generally the rated current of 1.5 times the rated current of the melt should be a multiple of the transformer allows overload and fuse Characteristics OK. Melt outlet circuit current protection fuse rated current, should be greater than the total current protection fuse rated current, nominal current by the melt loop normal maximum load current options and should escape the normal peak current. Shunt capacitor banks can fuse rated current is generally 1.5 to 2.5 times the rated current of the capacitor selection. 9. In order for rural low-voltage reactive power grid analysis, install a DTS (X) series active in the box, combo reactive multi-function meter (meter gauge plate mounted on the side), for the replacement of the original installation three single phase energy meter (DD862 Series meter) in order to monitor the operation of the load line. , Steel material, the kind of cold-rolled or hot-rolled steel sheet, how thickness, surface treatment, surface quality (paint, paint, electrostatic spray), color requirements, the door and the ground wire connection, power distribution box bottom, terminal block ( zero discharge, ground row) wiring is neat appearance, wire cross-sectional area, the case of components, insulation resistance test results, piece wire connections (whether a terminal over two wire), wire connections (tightness), each loop signs are complete. Using the supplied wiring diagram and the main components of the specification. 2, the power distribution box approach should improve procedures for handover, according to drawings for the physical check. Dual power transfer switch box should field test, if reliability, no exceptions signed by both parties recognized. Recipient to do the work product protection. And promised quality damage occurring in the future take full responsibility rests with the recipient. 3, the wire for examination should fully qualified, qualified certificate, production license, site physical sample testing to see whether the appearance of the given brand, the cross-sectional area of ??each wire diameter, thickness, thickness of exterior insulation and construction units must be installed before use material for examination, confirmed only after qualified for the project. National standards are: representation should be accompanied by product type, specification, standard number, name and origin labels and markings on the cable package, 20. c when the insulation resistance, 70. c when the insulation resistance. Sheath thinnest point thickness, the thickness of the insulating layer thinnest point. Must be carried out before entering the installation of equipment and materials for examination, there should be a production license, product quality inspection report, the Municipal Construction Committee of the equipment and materials and other copies of registration certificate information (chapter declared should cover supply units). Preservation of the original certificate by the construction units, supervision units to save a copy, plus equipment and materials for examination table. :