What are the requirements for PS cabinet customization?

The customization of PS(Power Supply) cabinet mainly has the following requirements:

I. Electrical performance requirements

Power input and output

Input specification: It is necessary to specify the input voltage range of the cabinet, such as single-phase 220V AC input or three-phase 380V AC input. When customizing, the matching with the actual power supply system should be considered, and at the same time, a certain voltage fluctuation adaptation range should be reserved, usually 10%-15% of the rated voltage.

Output interface: according to the number and power demand of connected equipment, reasonably design the number, type (such as national standard, American standard, European standard, etc.) and distribution position of output sockets (rows). And each socket should have a clear logo, which is convenient for users to identify and use. The total power capacity of the output socket should meet the sum of the maximum power of all connected devices, and a certain redundancy should be left (generally, it is recommended that the redundancy be 20%-30%).

Overload protection: In order to prevent overload caused by equipment failure or misoperation, PS cabinet must be equipped with overload protection devices, such as circuit breakers or fuses. The action current and action time of overload protection should be set reasonably according to the power capacity of the cabinet and the characteristics of the connected equipment. In general, the action current is set to 1.2-1.5 times of the rated current, and the action time is between several seconds and tens of seconds.

Wiring and grounding

Internal wiring: Power lines and signal lines inside the cabinet should be planned and wired reasonably. As far as possible, the power cord should be copper core cable with thick diameter to reduce line loss. Wiring should be neat and orderly, avoid crossing and winding, and keep a certain safe distance from the signal line (generally recommended not less than 30mm) to prevent electromagnetic interference.

Grounding system: Good grounding is an important measure to ensure the safe operation of PS cabinet and lightning protection of equipment. The cabinet shell must be reliably grounded, and the grounding resistance should be less than 4Ω. At the same time, the equipment inside the cabinet should be grounded separately, and the grounding line should be independent of the power line to ensure the reliability of grounding.

Second, the mechanical structure requirements

Cabinet structure

Size and space: according to the space size of the installation site and the number and size of the equipment accommodated, the overall size (height, width and depth) of the cabinet is determined. The space inside the cabinet should be reasonably divided, and sufficient equipment installation location and wiring space should be reserved. Generally speaking, the equipment installation space should account for 60%-70% of the internal space of the cabinet, and the wiring space should account for 30%-40%.

Material and strength: the cabinet frame is usually made of high-quality steel, such as cold-rolled steel plate, and the thickness is generally between 1.2 mm and 2.0 mm to ensure the overall strength and stability of the cabinet. Cabinet doors and side plates can be made of steel plates or aluminum alloys, which should have certain strength and be easy to install and disassemble. For cupboard doors that need to be operated frequently, firm hinges and handles should be installed, and the position of the handles should conform to the ergonomic principle, which is convenient for users to operate.

Protection level: If the PS cabinet is installed in an indoor environment, the protection level is generally required to reach IP20 or above, which can prevent solid foreign bodies with a diameter greater than 12mm from entering the cabinet and has a certain protective effect on people contacting the internal live parts. If installed outdoors or in harsh environment, the protection level should be improved accordingly, such as IP54 or IP55, which can prevent dust and water from splashing.

Equipment installation and fixing

Installation mode: standard equipment installation guide rails or installation holes should be designed in the cabinet to facilitate the installation of various power supply equipment (such as UPS and power distribution cabinets). The size of the installation guide rail should meet the international or domestic standards (such as the 19-inch standard), and the spacing of the installation holes should be uniform and reasonable, which is convenient for fixing the equipment.

Fixing devices: In order to ensure the stability of the equipment in the cabinet, adequate fixing devices, such as screws, nuts and clamping rails, should be provided. For heavier equipment, a special bearing bracket or tray should be set at the bottom of the cabinet to disperse the weight of the equipment and prevent the cabinet from being deformed.

Third, heat dissipation and ventilation requirements

Heat dissipation mode

Natural heat dissipation: If the power and calorific value of the equipment in the cabinet are low, natural heat dissipation can be adopted. Vents are set at the top, bottom and side of the cabinet, and the area of the vent should be calculated according to the calorific value of the equipment. Generally speaking, the total area of ventilation holes should not be less than 10%-15% of the surface area of the cabinet. Vents should be equipped with dust screens to prevent dust from entering the cabinet.

Forced air cooling: for PS cabinets with high power and high calorific value, forced air cooling is needed. Install fans (generally axial fans) in the cabinet, and the number and position of fans should be rationally arranged according to the heat distribution inside the cabinet. The air volume and wind pressure of the fan should meet the cooling requirements of the cabinet, and the noise level of the fan should be considered. Generally, the noise should be controlled below 60dB.

Ventilation passage design

It is necessary to build a reasonable ventilation channel inside the cabinet, so that cold air can enter the cabinet from the bottom or side, and be discharged from the top after heat dissipation by the equipment. Keep a certain distance between devices (generally not less than 50mm) to ensure good ventilation. At the same time, there should be no obstacles in the ventilation channel to avoid affecting air circulation.

Fourth, environmental adaptability requirements

Temperature and humidity

Working temperature range: PS cabinet should be able to work normally in a wide temperature range, and the general requirement is-10℃-+50℃. In the low temperature environment, the starting performance of equipment and the performance change of electronic components should be considered; In the high temperature environment, it is necessary to ensure that the cooling system can work effectively, so that the temperature of the equipment does not exceed its maximum allowable working temperature.

Humidity range: The working humidity range of the cabinet is generally 20%-80% (relative humidity). Excessive humidity may cause problems such as damp and short circuit of equipment; If the humidity is too low, static electricity may be generated, which will cause damage to electronic equipment. Therefore, in some environments where humidity changes greatly, it may be necessary to configure a humidity adjusting device.

erosion resistance

If the PS cabinet is installed in a place with corrosive gas (such as chemical workshop, seaside and other environments), the surface of the cabinet should be treated with special anti-corrosion, such as plastic spraying and zinc plating. In addition, the sealing performance of the cabinet should be good, and the corrosive gas should be minimized to enter the cabinet. For internal equipment, anti-corrosion components or corresponding protective treatment can also be adopted.

V. Monitoring and management requirements

Condition monitoring

Power parameter monitoring: the customized PS cabinet should have the power parameter monitoring function, which can monitor input and output voltage, current, frequency, power and other parameters in real time. These parameters can be displayed on the display screen on the front panel of the cabinet, or uploaded to the remote monitoring system through communication interfaces (such as RS485 and Ethernet).

Equipment status monitoring: Monitor the equipment in the cabinet (such as the battery status of UPS, the switch status of power distribution cabinet, etc.), and send out an alarm signal in time when the equipment fails or is abnormal. The alarm mode can be acousto-optic alarm. An alarm indicator light and buzzer are set on the front panel of the cabinet, and alarm information can be sent to the remote monitoring terminal.

remote administration

Communication interface: In order to realize remote management, PS cabinet should be equipped with communication interface and support common communication protocols (such as SNMP, Modbus, etc.). Through these communication interfaces, managers can switch the power supply of the cabinet and set parameters in the remote control center, and can obtain the running status information and historical data of the cabinet.

Management software: special power management software can be developed, and the software has a graphical interface, which is convenient for managers to centrally manage multiple PS cabinets. The management software can realize the functions of equipment configuration management, real-time data display and analysis, fault diagnosis and early warning.