What should be the momentary rating of switching devices or disconnecting links in a busway run?

The momentary rating of switching devices or disconnecting links in a busway run should indeed be the same as the busway rating. This ensures that the switching devices can handle the maximum current that the busway is rated for without risk of failure or damage during normal operational conditions.

A busway is designed to carry a specific amount of current safely, and any connected devices must be capable of interrupting the current flow without degrading performance or risking safety. If the momentary rating were higher, it could imply unnecessary additional capacity that the switching devices would not need. If it were lower, the devices could potentially fail to interrupt current flow, risking equipment damage and impacting overall safety. Maintaining the same rating ensures compatibility and safety throughout the electrical system.

Consequently, ensuring that the momentary rating aligns with the busway rating is critical for the reliable operation and safety of electrical installations.