Technical requirements for installation of switchboard and cabinet during electrical construction

Switchboard, cabinet stable installation:

Cabinet (plate) installation. The cabinet should be placed on the foundation steel in order according to the layout of the construction drawings. Separate cabinets (trays) only find the verticality of the faces and sides of the cabinets. After the cabinets (trays) are in place, find the cabinets at both ends first, stretch a small line from the bottom of the cabinet to two-thirds of the height, and find the cabinet one by one. The standard is not based on the cabinet surface. The timing is adjusted with 0.5mm iron sheets, and each gasket cannot exceed three pieces. Then, according to the size of the cabinet fixed screw holes, drill holes in the basic steel frame with an electric hand drill. Generally, if there is no requirement, drill φ12.2 holes for the low pressure cabinet and φ16.2 holes for the high pressure cabinet, and fix them with M12 and M16 galvanized screws respectively. Table 2-31 lists the permissible deviations.

After the cabinet (plate) is in place and straightened and levelled, the cabinet body is fixed with the base steel. The cabinet is connected to the cabinet and the cabinet is connected to the side baffle with galvanized screws.

Cabinet (panel) grounding: Each cabinet (panel) is separately connected to the base steel. The nose of each cabinet is welded on the base steel side at the bottom left of the back, and securely connected to the ground terminal on the cabinet with a 6mm2 copper wire.

For the preparation of the bus bar on the top of the cabinet (tray), see "Installation of the bus".

Allowable deviation of disk and cabinet installation

entry

Allowable deviation (mm)

Perpendicularity (per meter)

< 1.5

Horizontal deviation

Top of two adjacent disks

< 2

Top of a row of discs

< 5

Two sides next to each other

< 1

Disk deviation

Make a row of plates

< 5

Interdisk joint

< 2

Cabinet (plate) secondary small wire connection:

According to the schematic diagram, check whether all electrical components on the cabinet (panel) are consistent, and its rated voltage must be consistent with the voltage of the control and operation power supply.

Lay the control cable connection line between the phase and the cabinet according to the drawing. Cable laying requirements see "Cable Laying".

After the control line is calibrated, each core wire is simmered into a circle, and connected to each terminal board with galvanized screws, eye rings and spring pads. Generally, one terminal on each side of the terminal board must press one wire. A maximum of two wires must be pressed. An eye ring must be added between the two wires. Multiple strands of wire should be boiled tin, no broken strands.

Cabinet (plate) test adjustment:

The high voltage test shall be carried out by the test unit approved by the local power supply department. The test standards are in line with the national standards, the provisions of local power supply departments and the requirements of product technical data.

Test contents: high voltage cabinet frame, bus bar, lightning arrester, high voltage porcelain bottle, voltage transformer, current transformer, high voltage switch, etc.

Adjustment content: overcurrent relay adjustment, time relay adjustment, signal relay adjustment and mechanical chain adjustment.