What points should be paid attention to in the layout of the electrical control cabinet

What points should be paid attention to in the layout of the electrical control cabinet

First of all, the basic specification requirements are met, GB

1) Make sure all equipment in the electrical control cabinet is well grounded, using short and thick grounding wires to connect to a common grounding point or grounding busbar. Any control device connected to the inverter (e.g. a PLC) should be co-grounded with it and should also be grounded with short and thick wires. Flat conductors, such as metal mesh, are preferable because they have a low impedance at high frequencies.

2) The low-voltage unit, relay and contactor of the electrical control cabinet are protected by fuses; When the connection from the inverter to the motor exceeds 100m, when the power supply capacity of the inverter is greater than 600kW A or the power supply capacity is greater than 10 times of the capacity of the inverter, it is recommended to add the input and output reactor.

3) Make sure that the contactor in the electrical control cabinet has an arc extinguishing function, the AC contactor adopts R-C suppressor, and the DC contactor adopts the "flywheel" diode, which is loaded into the winding. The use of varistor suppressors is also very effective.

4) If the device is operating in a noise-sensitive environment, EMC filters can be used to reduce radiated interference.

As an electrician apprentice for a year at a company that specializes in this, you can learn a lot if you want to.

As the name suggests, the electrical control cabinet is an electrical cabinet that serves as an electrical control function. The electrical control cabinet is divided into a traditional relay control cabinet and a PLC integrated control cabinet. The relatively simple control is controlled by relays, and the complex control is generally controlled by PLC (PLC refers to programmable logic control).

The control cabinet is to assemble switchgear, measuring instruments, protective appliances and auxiliary equipment in a closed or semi-enclosed metal cabinet or screen according to the requirements of electrical wiring, and its arrangement should meet the requirements of the normal operation of the power system, facilitate maintenance, and do not endanger the safety of people and surrounding equipment. During normal operation, the circuit can be switched on or off with the help of manual or automatic switches. In case of failure or abnormal operation, the circuit is cut off or alarmed with the help of protective appliances.

The measuring instrument can be used to display various parameters in operation, and some electrical parameters can also be adjusted, and the deviation from the normal working state can be prompted or signaled. It is often used in various power generation, distribution and substations.

1. The cabinet door is 25mm above the ground and the thick mounting plate, and there are 20mm wide U-shaped curved edges on both sides, which makes the mounting plate stronger and easy to handle.

2. The three cable introduction cover plates at the bottom of the box can be replaced with each other, which is easy to move, easy to import cables, and easy to open holes into the line.

3. There are grounding bolts on the door 5. The load-bearing hinge is easy to install, and it is easy to change the cabinet door. The door can be opened 130°.

4. The plastic sliding device can be used to push the mounting plate into the cabinet from the front of the cabinet through the guide rail, and the solid rectangular frame can not only strengthen the strength of the front door, but also be used to fix and install electrical components (with the door installation horizontal bar).

5. The backplate can be easily installed and fixed with screws; Doors can also be replaced.

6. Standard MS821 lock, upper, middle and lower three-point locking cabinet door.

7. Sealing ring: polyurethane foam sealing strip to ensure the protection level.

8. Add a waterproof edge to the cabinet door frame to cooperate with the door sealing ring to prevent water and dust from falling into the cabinet.

9. (Single door) left and right interchangeable door design, easy to use. Standard modular mounting hole design for easy installation.

10. Inner lamp, easy to install and test (optional).

11. Document bag, convenient for on-site work (optional).

12. The installation beam can also be installed in the cabinet without using the mounting plate (optional).

13. Fan and filter screen to ensure ventilation in the cabinet, protection level IP54 (optional).

14. Base, fixed, movable, easy to disassemble and install (optional).

15. Double mounting plate, large installation capacity (optional).

16. Door installation strip, easy to install.

17. The full frame side panels, front and rear doors, top plates and bottom plates of the cabinet can be removed, which can adapt to various requirements and facilitate installation and maintenance.

1) Keep sufficient distance from doors and windows, and the distance between doors and windows and the front of the control cabinet is not less than 600mm.

2) The distance between the side of the jujube hole cabinet and the wall is not less than 100mm.

3) The installation distance between the control cabinet and the mechanical equipment in the computer room shall not be less than 500mm.

4) After the control cabinet is installed, the verticality is not more than 3 1000, and the ground of the bridge sail foot bolt is fixed with the ground of the Minyan hail machine room.

First. In order to avoid power interference, the power cords in the electrical control cabinet should be kept away from any and all cables, and filters should be installed near the entrance to ensure that the outside power supply system is interfered with into the cabinet.

Second. The installed filter should be as close as possible to the power input socket, and the incoming and outgoing wires should be installed near the bottom wiring, and the two types of wiring must be separated, and parallel lines can not be taken, and it is best to have an angle difference of 180. Then the power line of the output of the filter and the input power line should be far away, so that they can not be close together to avoid interference from reappearing on the power line.

Third. An important component of the electrical control cabinet should be a low-pass filter, like the AC power supply of the central CNC system, so as to reduce the possibility of high-frequency signals that are interfered with by the power supply. If it is economic, technical and other aspects are allowed, the central module of the CNC control system in the motor drive system

The power supply on the inverter, computer and control circuit can be equipped with different suitable filters, so as to avoid not only the interference of the power supply, but also the interference between the modules.

Fourth. The wiring of strong and weak signals in the electrical control cabinet must not be too close, let alone arranged in a wire duct.

The above is the place to pay attention to the wiring direction of the electrical control cabinet, and it is not a big problem to pay strict attention to it and follow the specifications.

The distribution cabinet is mainly some switches, which are responsible for power distribution and line protection.

The control cabinet is mainly to implement some control functions, which generally have switches, relays or PLCs and the like.