What factors need to be considered when choosing a switchboard?

When selecting a switchgear, multiple factors need to be considered comprehensively to ensure it meets the actual power demand and guarantees the safe and stable operation of the power system. The following are some key factors to consider:

Electrical Parameters

Rated Voltage: Needs to match the voltage of the power supply system, such as the common 0.4kV low-voltage system or 10kV high-voltage system, to ensure the switchgear can connect normally and operate stably.

Rated Current: Select based on the maximum current of the actual load. Consider potential future load growth; generally, some margin should be left to avoid overload operation.

Short-Circuit Withstand Current: Reflects the switchgear's ability to withstand short-circuit current impact during a short-circuit fault. It should be determined based on the short-circuit capacity of the power system to ensure the switchgear will not be damaged by the short-circuit current during a short-circuit fault.

Load Characteristics

Load Type: Clarify whether the load is resistive, inductive, or capacitive. For example, inductive loads such as motors have large inrush currents during startup, requiring the switchgear to have corresponding overload protection and withstand capability; while for electronic equipment loads with higher voltage stability requirements, the switchgear needs to provide stable voltage output.

Load Capacity: Calculate the total capacity of all loads and consider the simultaneous operation coefficient to determine the total load capacity of the switchgear. If the load capacity is large, it may be necessary to select a larger switchgear or use multiple switchgears for distributed power supply.

Protection Level

Determine the protection level based on the usage environment. For example, in an indoor dry and clean environment, generally selecting an IP30 or IP40 level switchgear is sufficient; while in industrial environments with dust, water vapor, or corrosive gases, a higher protection level switchgear such as IP54 or IP65 is needed to prevent external substances from entering the switchgear and affecting the normal operation of electrical equipment.

Structural Form

Fixed or Draw-out Type: Fixed switchgear has a simple structure and lower cost, suitable for places with stable loads and less maintenance and repair; draw-out switchgear has higher flexibility and reliability, facilitating the repair and replacement of individual circuits, suitable for places with high requirements for power continuity, such as hospitals and data centers.

Cabinet Size and Layout: Select the appropriate size of the switchgear based on the size of the installation space, and consider whether the layout of the electrical components inside the cabinet is reasonable for operation, maintenance, and repair. For example, for large switch rooms, floor-standing switchgear with larger size and reasonable layout can be selected; while for small spaces with limited space, wall-mounted switchgear can be considered.