What must the voltage rating of a switchboard be in relation to the system voltage?

The voltage rating of a switchboard must be at least equal to the system voltage to ensure safe and reliable operation. This requirement is critical for several reasons.

First, a switchboard that is rated lower than the system voltage can lead to insulation failure, overheating, and potential equipment damage due to the increased stress imposed on its components. When the operating voltage exceeds the rating of the equipment, there is a significant risk of electrical arcing or short-circuiting, which can not only damage the switchboard but also create hazardous conditions for operators and maintenance personnel.

Furthermore, safety standards and electrical codes often specify that equipment ratings must meet or exceed the operating conditions to promote safe handling and minimize risks associated with electrical faults. Having a voltage rating at least equal to the system voltage also ensures that the switchboard can handle transient conditions and surges that may occur during normal operation or fault events.

In contrast, a switchboard rated double the system voltage, while it may provide a higher margin of safety, could be impractical and unnecessary in many applications, potentially leading to increased costs and overengineering without substantial benefits.