Choose according to control and distribution needs
Control cabinet
If your main purpose is to accurately control the operation of the equipment, such as the speed regulation and forward and reverse rotation of the motor, or to realize complex automated control processes, such as the sequential control of automated equipment on industrial production lines, closed-loop control of physical quantities such as temperature and pressure, etc., then you should choose a control cabinet. For example, in an automated packaging production line, the control cabinet can control the speed of the conveyor belt, the action of the packaging machine, etc. according to the sensor signal to ensure the efficiency and accuracy of the packaging process.
Distribution cabinet
When the focus is on the reasonable distribution of electrical energy to multiple branches or electrical equipment, such as distributing electrical energy to lighting, sockets, air conditioners and other equipment on different floors in the building electrical system, or distributing electricity to power and lighting equipment in different workshops in the factory, the distribution cabinet is a suitable choice. For example, in the distribution room of a large shopping mall, the distribution cabinet distributes the electrical energy of the total power supply to the distribution boxes on each floor, and then the distribution boxes distribute it to the specific electrical equipment of the store.
Consider the load characteristics of the equipment
Control cabinet
For controlling high-power equipment or equipment with special requirements for starting current, such as large motors, the capacity of the control components in the control cabinet should be considered. If the motor needs to start and stop frequently, or needs soft start or variable frequency start function, it is necessary to select a control cabinet equipped with a corresponding soft starter or frequency converter. At the same time, the appropriate controller should be selected according to the control signal type (such as analog signal, digital signal) and control accuracy requirements of the equipment. For example, for high-precision CNC machine tools, the control cabinet needs to be able to receive and process high-precision position control signals.
Distribution cabinet
The capacity of the distribution cabinet should be determined based on the total power of the load and the power of each branch. Calculate the total power of all electrical equipment, including the simultaneous coefficient (considering the situation where the equipment is not used at the same time), so as to select the appropriate busbar specifications and switchgear. For example, in a small factory, there are several machine tools and some lighting equipment. After calculating the total power, the switch capacity and busbar current carrying capacity of the distribution cabinet should be able to meet the maximum load requirements, and a certain overload margin should also be considered.
Selection based on working environment conditions
Control cabinet
In harsh environments, such as places with high temperature, humidity, dust or corrosive gases, the control cabinet needs to have good protection performance. If the working environment temperature is high, a control cabinet with a heat dissipation device (such as a fan or radiator) should be selected, and the cabinet material should be able to withstand high temperatures. In a humid environment, the protection level of the control cabinet (such as IP54 and above) should be high enough to prevent moisture from entering. For environments with dust or corrosive gases, the control cabinet should be well sealed and may need to be equipped with an air filter. For example, in a chemical production workshop, the cabinet material of the control cabinet should be corrosion-resistant stainless steel, and the vents should be equipped with anti-corrosion and dust-proof filtering equipment.
Distribution cabinet
Similarly, the distribution cabinet also needs proper protection in harsh environments. In outdoor environments, the distribution cabinet should have the functions of waterproof, sun-proof, and wind-proof, and the protection level is generally not less than IP55. In places where there is a risk of fire, the outer shell material of the distribution cabinet should have fire-proof properties. For example, in the outdoor substation distribution cabinet, the cabinet body is made of thickened steel plate, the surface is treated with anti-corrosion and sun-proof, and the cabinet door is well sealed to prevent rain and wind and sand from entering.
Considering from the perspective of safety and reliability
Control cabinet
To ensure safety, the control cabinet should have a complete grounding system to prevent electric shock accidents. The internal control components must comply with relevant safety standards, such as electrical clearance and creepage distance. In terms of reliability, select components such as controllers and relays with reliable quality, and consider the anti-interference ability of the control cabinet, especially in industrial environments with electromagnetic interference. For example, in workshops with a large number of frequency converters and motors, the wiring of the control cabinet should use shielded wires, and the controller should have anti-electromagnetic interference functions to avoid distortion of control signals.
Distribution cabinet
The safety of the distribution cabinet is crucial, and the short-circuit protection and overload protection functions of the switchgear must be normal. All electrical connections must be firm and reliable to prevent heating and sparking. In terms of reliability, the current carrying capacity and insulation performance of the busbar must be good, and the switchgear must be able to work stably. For example, in the distribution cabinets in important places such as hospitals, high-quality circuit breakers should be used, and there should be backup power switching devices to ensure the reliability of power supply.
Make a decision based on cost and maintenance convenience
Control cabinet
In terms of cost, consider the impact of the complexity of the control cabinet’s functions on the price. If complex automation control functions are required, such as the use of high-end PLCs and multiple sensors, the cost will be relatively high. At the same time, consider long-term operating costs, such as the energy consumption of the controller. In terms of maintenance convenience, the layout of the control cabinet should be reasonable to facilitate maintenance personnel to inspect, repair and replace control components. For example, the components in the control cabinet should be clearly marked, and there should be enough space for disassembly and installation of new components.
Distribution cabinet
The cost of the distribution cabinet mainly depends on factors such as capacity, quality of switchgear and protection level. Try to choose products with high cost performance while meeting the requirements of power distribution. For maintenance convenience, the door of the distribution cabinet should be easy to open, and the switchgear and metering instruments inside should be easy to operate and observe. For example, in the distribution cabinet in the distribution room of a building, the operating handle and indicating instrument of the switchgear should be installed in a position that is convenient for staff to view and operate, and the busbar connection part should be easy to inspect and tighten.
