China One electric introduce ：Electrical high and low voltage distribution cabinet installation specifications

1. Check the preparation before installation

Before installation, the supervision engineer and Party A's engineer shall check whether the passage is smooth, and ask the general contractor to build a simple transportation passage to connect with the installation points if necessary. The layout of the construction site shall meet the installation requirements. Building a safe civilization. At the same time, the layout of the installation unit construction equipment should be checked, and the installation unit should be urged to check the construction equipment to ensure that it is in good condition. Before the high voltage equipment arrives at the site, the distribution room, trench and base channel steel should be completely completed.

1), power distribution room

Power distribution room: Before the construction of the power distribution room, the detailed drawings required for the construction of the power distribution room should be handed over to the construction party (within two weeks after the signing of the contract, it is necessary to confirm the location) the content, content and completion time of the drawings) During the construction of the power distribution room, our technical personnel or cooperative units should be supervised on site to avoid construction errors. (It takes about 2 weeks to build the switchboard)

2). Basic: The placement of the channel steel should correspond to the equipment air duct reserved in the power distribution room, and the minimum distance between the equipment and the wall should be clear (the distance is too close, the equipment door cannot be opened). (Welding channel steel takes about 2 days, our technicians must be present to guide)

Equipment arrival site:

3) If no power distribution room and foundation are built, the equipment must have a storage place (to protect it from rain or provide the necessary rain protection materials).

2. Installation

2.1 The doors and Windows of each power distribution room shall be sealed and the room shall be kept clean.

2.2 The switchboard has been firmly installed. The device on the board is firmly attached to each component.

2.3 Ground the panel and cabinet securely. Openable trays and cabinet doors with appliances should be reliably connected to a grounded metal frame by flexible wires.

2.4 The junction box should be firmly installed and closed. Installation location should be easy to check. For continuous installation, they should be arranged neatly.

2.5 The wiring in the switchboard should be horizontal and vertical, the screws should not be loosened, and the end of the wire should be in good contact.

2.6 The components in the disk are fixed and reliable, do not come loose, and the contacts are free of oxidation and burrs.

2.7 The connector of the secondary circuit shall be made of copper products. Specific requirements for wiring:

2.7.1 The circuit connection (bolt connection, insert and remove, welding, etc.) should be firm and reliable.

2.7.2 The end of the cable core wire and supporting wire shall be marked with its circle number; Numbers should be correct, legible, and not easily faded.

2.7.3 Wiring is neat, clear and beautiful; The wires are well insulated and undamaged.

2.7.4 Cables in cabinets or cabinets should not have connectors.

2.7.5 There is usually one cable on each side of each patch board and no more than two cables.

2.8 The charged body of the secondary circuit should be below 400 V and the electrical gap between the charged body and the ground should be not less than 4 mm. The leakage distance should not be less than 6mm.

2.9 Wires used to connect moving parts (door equipment, console board, etc.) shall still meet the following requirements:

2.9.1 Multiple strands of flexible conductors shall be used and shall be laid with an appropriate margin.

2.9.2 The wiring harness should have a reinforced insulation layer (e.g. plastic sleeve, etc.).

2.9.3 When connected to an electrical appliance, the end shall be tight and not loose or broken.

2.9.4 Clips are used to secure both ends of an active part.

2.10 The control cables and cores in the panels and cabinets to be imported must meet the following requirements:

2.10.1 The cables of the cabinet and the spool should be arranged neatly to avoid crossover, and should be firmly fixed so that the connecting terminal board is not subjected to mechanical stress.

2.10.2 Steel belts of armored cables must not enter coils or cabinets. The cutting end of the armored steel tape should be tight;

2.10.3 Control cables for transistor protection and control logic circuits, when using shielded cables, the shielding layer should be grounded; If no shielded cable is used, the standby core cable should be connected to the ground.

2.10.4 Rubber insulated core wires should be protected by insulated tubes;

2.10.5 The cable core wires of the reel and the cabinet should be arranged vertically or horizontally, and should not be skewed or cross-connected at will. Spare core should have appropriate allowance.

2.11 If the insulated wires may be corroded by oil, oil-resistant insulated wires should be used or oil-proof measures should be taken.

2.12 Technical Requirements for safety of power distribution devices:

2.12.1 When two or more power supplies are used for power supply, an interlocking device shall be installed between the main input and the contact switch of each power supply (except for the device dispatched by the power supply department).

2.12.2 Interlocking devices shall be installed between the isolation switch and the corresponding circuit breaker of the complete set of equipment in the 10 kV room.

2.12.3 The phase arrangement of power distribution devices shall meet the following requirements:

(1) The phase arrangement of each circuit in the same distribution equipment should be as consistent as possible.

(2) The hard bus should be painted in color: yellow phase; b phase green; C phase red; Zero line black.

(3) The soft bus should be marked with different phases.

(4) Conductors within the spacing of the distribution equipment shall retain a temporary ground line suspension position.

2.13 The following requirements must be met:

2.13.1 The wiring board should be undamaged, firmly fixed, and well insulated.

2.13.2 The patch board should be easy to replace and connect.

2.13.3 If the loop voltage exceeds 400 volts, the terminal block shall have adequate insulation and be marked in red.

3 Checking

3.1 Check

3.1.1 Are the ventilation, lighting and fire safety devices in the high and low voltage power distribution room normal?

3.1.2 The distribution panel door is tight and not damaged. Switchboard clean and dust-free.

3.1.3 All power distribution screens in the site must be listed for warning.

3.1.4 The signal light, bell and accident bell of the signal equipment circuit shall be accurately displayed and work reliably.

3.1.5 Whether the voltage and current of the motor in the distribution cabinet are normal (not exceeding 5% of the rated value).

3.1.6 Whether the bus bar and each contact point are overheating, indicating whether the temperature wax sheet is melted and whether the insulating bakelite is burned out.

3.1.7 Whether the electrical components in the switch cabinet have odor and sound during operation.

3.1.8 Whether the oil level of the oil injection equipment is normal, whether the oil color is darker, and whether there is oil leakage.

3.1.9 Whether the display of instruments, signals and indicators is correct, and whether the position of the relay protection pressure plate is correct.

3.1.10 Do relays and DC equipment work well?

3.1.11 Check whether the wiring of the ground zero device is loose or broken.

3.1.12 Whether the insulation of porcelain bottles, insulation sleeves, wall bushings, etc. is clean, and whether there are damage cracks and discharge traces.

3.1.13 Are the mechanical interlocks of circuit breakers and isolation switches flexible and reliable? If the electromagnetic interlock device is used, it must be energized to check whether the electromagnetic lock is flexible and whether the opening and closing are accurate.

3.2 Monthly Check

Monthly comprehensive inspection of the motor, every operating and electrical part of the distribution cabinet, the dynamic closing test of the electromagnetic starter of the relay and the sensitivity test.

3.3 Annual Inspection

Every three years, the electric motor and distribution cabinet are tested for relays and verified by the power supply personnel.

3.4 Check and Maintenance

3.4.1 Check and maintenance once a month.

3.4.1 The power failure maintenance line must first be listed before it is operated on to display a warning.

3.4.2 The motor, cable and distribution panel must be properly grounded, and the grounding resistance should not be greater than 4 ohms.

3.4.3 The motor measures the DC impedance and performs AC withstand voltage test. Current transformers and voltage transformers are used for voltage resistance testing and current ratio testing.

3.4.5 Test the DC voltage leakage of the cable; Relay overhauled and reset.

3.4.6 Remove the oil switch for inspection, maintenance, adjustment and tightening; The pressure test of the arrester is also carried out.