Why can't the distance between the housings of low-voltage capacitors be less than 50mm?

In the power system, low-voltage capacitors are important equipment for improving power factor and enhancing power quality. The requirement for maintaining an adequate distance between the capacitor shells is not set arbitrarily; it is based on multiple technical considerations. Then, why can't the distance between the low-voltage capacitor shells be less than 50mm?

I. Heat Dissipation Requirements and Temperature Control

During operation, capacitors will generate a certain amount of heat. If the distance between the casings is too small:

1. It will hinder the natural convection of air, resulting in the accumulation of heat.
2. Adjacent capacitors may heat each other, resulting in a temperature superposition effect.
3. Long-term overheating will accelerate the evaporation of the electrolyte and the aging of the medium.

The appropriate spacing ensures good ventilation and heat dissipation conditions, which is crucial for extending the service life of the capacitor.

II. Electrical Safety Considerations



1. Prevent possible flashover phenomena between the enclosures
2. Reduce the risk of mutual interference of electric fields between adjacent capacitors
3. Provide a safe isolation space for possible fault arcs
4. Facilitates the operation of security checks by maintenance personnel

III. Mechanical Stability and Maintenance Convenience



1. Appropriate spacing can prevent the shell from being squeezed by each other due to thermal expansion and contraction.
2. Reserve safety margin for possible slight deformation of the shell.
3. Space for tool operation during installation and maintenance
4. Facilitates fault detection and replacement of individual capacitors