TABLE OF CONTENTS From the preceding sections it can be seen that the means by which electrical machines fail depends not only on failure modes, which will be discussed in Chapter 3, but also on the type of machine and the environment in which it is working. However, it is possible to identify certain basic failure mechanisms that apply to all machines. We must then identify the early root causes of these faults because it is by detecting these root causes that monitoring becomes possible and beneficial.
Any fault involves a failure mechanism, progressing from the initial fault to the failure itself. The time taken for such a progression will vary, depending on a wide range of circumstances. What is important, however, is that all faults will have early indicators of their presence and it is here that monitoring must seek to look and act. Also, any fault is likely to have a number of possible causes and is likely to give rise to a number of early indications. A typical route to failure is shown in Figure 3.1.
In this and the following section we will give a description of the ailments with which electrical machines are afflicted. A detailed schedule of failure mechanisms for electrical machines is given in the Appendix where the failure modes and root causes for electrical machines are elaborated. By studying the Appendix the reader can identify what parameters should be worth monitoring in order to give an early indication of...
