What is considered a good result in a 5 year network protector contact resistance test?

A good result in a 5-year network protector contact resistance test is typically around 25 micro ohms. This value is significant because it indicates that the contact resistance is low enough to ensure efficient operation of the network protector, minimizing energy loss and heat generation due to resistance. Maintaining low contact resistance is crucial for performance and reliability in electrical systems, as higher resistance values can lead to overheating, inefficiencies, and potential failure of the protective device.

While other values, such as 15 micro ohms, may seem favorable, they might not be realistically achievable due to typical wear and tear over time. The chosen value of 25 micro ohms represents a balance between optimal performance and realistic, achievable conditions in a well-maintained system after five years of service. Lower values may not necessarily indicate a problem, but they are generally not expected from a practical standpoint in aging systems.