Installation requirements for high and low voltage distribution cabinets

Before installation, the environment in the control room should be qualified, all interior decoration construction has been completed, and the room is clean and safe.

1. Installation and fixation of power distribution cabinet:

① After the distribution cabinet is shipped to the site, organize an unpacking inspection to check for deformation, paint drop, whether the instrument parts are complete, whether the spare parts, manuals, etc. are defective, and make a record of unpacking.

②According to the layout of the construction drawings, place the switchgear on the foundation steel in order. After the rows of cabinets are in place, first align the cabinets at both ends, and then stretch small lines from the bottom of the cabinet to the upper two-thirds of the height, and align the cabinets one by one, taking the cabinet surface as the standard. When aligning, use 0.5mm shims to adjust, and each place can not exceed three shims at most.

③After aligning in place, fix it according to the size of the fixed screw hole of the cabinet. The cabinet body and the cabinet body, the cabinet body and the side baffle are all connected with galvanized screws. The high and low voltage switch cabinets are firmly welded to the reserved angle steel. The exposed part of the cable interlayer is covered with patterned steel plates, and the insulation is 1200mm×10mm (width×thickness) at the front and back of the cabinet.

④The level deviation of the tops of the two adjacent cabinets of the switchgear is not more than 2mm. The horizontal deviation of the top of all cabinets is not more than 5mm. The unevenness of the sides of the adjacent two cabinets is not more than 1mm. The unevenness of all the cabinet surfaces is not more than 5mm, and the indirect seam of the cabinet is not more than 2mm.

⑤ After the equipment is positioned, tighten and check the internal fasteners again, especially at the conductor connection ends. After the wiring in the cabinet is completed, use a vacuum cleaner to remove the debris in the cabinet, keep the inside and outside of the equipment clean, and accurately identify the equipment number and circuit number.

After the power distribution cabinet is installed, install the bridge above the cabinet. The position of the openings for the cables in and out of the power distribution cabinet shall be reserved by the supplier according to the size. After the cable is laid, it is closed.

The bridge frame and the grounding busbar in the cabinet are reliably grounded with a dedicated grounding wire.

2. Secondary circuit wiring:

Before leaving the factory, the power distribution cabinet should complete the wiring of the secondary circuit in the cabinet and related inspection tests. After the power distribution cabinet equipment arrives on site, the inspection and acceptance shall be organized in time under the supervision and guidance of the on-site engineers and supervisors of Party A. The relevant technical documents shall be complete, the power distribution cabinet shall be packaged and sealed well, all components shall be complete and intact, and the wiring shall be reliable.

After the power distribution cabinet is installed and fixed, the insulation test of the secondary wiring circuit of the power distribution cabinet should be carried out one by one. The 500V insulation test instrument is used for the test, and the test result is required to be greater than 1MΩ.

All secondary loop control wires or cables are made of multiple strands of soft copper wire, and the wiring terminals are of appropriate specifications. After tinning, use special crimping pliers for crimping, and neutral flux should be used when tinting.

3. Handover test

4. Other requirements

①The installation of drawer type switch cabinet shall also meet the following requirements:

a. The drawer pushes and pulls flexibly and lightly, without jamming or collision;

b. The center lines of the moving contact and the static contact are consistent, and the contacts are in close contact;

c. The mechanical interlocking or electrical interlocking device of the drawer operates correctly and reliably to ensure that the isolation contacts can be separated after the circuit breaker is opened;

d. The grounding contact between the drawer and the cabinet is in close contact; when the drawer is pushed in, the grounding contact of the drawer comes into contact first than the main contact, and the procedure is reversed when it is pulled out.

②Before the insulation test of the secondary circuit of the power distribution cabinet, carefully check the design drawings, and the vulnerable components in the cabinet should be disassembled in advance.

③ During the installation process of the power distribution cabinet, the paint layer should be intact, free from damage, and the lighting inside the cabinet should be complete.

④Equipment enclosures in the substation room must be well grounded