Testing electrical insulation can be quick and easy when using test equipment specifically designed to perform insulation resistance measurements. A good insulator should have a very high resistance to current flow. Factors such as temperature, electrical and mechanical stresses, weather and moisture ingress are all capable of adversely impacting the characteristic qualities of materials that make them such good insulators. The degradation of these materials over time can result in unplanned outages, safety concerns for personnel and an overall degradation of power system reliability.
An insulation resistance test is conducted to examine the effectiveness of insulation in a variety of electrical power system apparatus. Faulty electrical insulation is the source of dangerous shock hazards and can often cause ancillary damage to adjacent equipment as well. Routine electrical testing and maintenance can help to identify when insulation has deteriated before it reaches the point of failure, saving the expense of repairs and unplanned outages.
Protective Relays could be characterized as circuit managers with varying degrees of supervisory and control capabilities depending on the complexity and criticality of the circuit. They are designed to recognize abnormal or fault conditions, and to isolate the affected portion or the electrical system. Not only does this allow the unfaulted portion of the electrical system to continue to function normally, but it diminishes the impact of the faulted portion of the system. Changes to power system circuits and the coordination of protective devices can change due to age, loading, environmental impacts, new construction, etc. It is therefore critical that these devices function properly and are appropriately coordinated when they are called into action.