What procedure is used to test generator or motor armature windings for opens?

Using a growler is an effective method to test generator or motor armature windings for opens because it allows for the detection of faults such as open circuits in the windings while the armature is in a controlled environment. In this procedure, the growler generates a magnetic field that induces current in the windings, allowing them to be tested for continuity and faults.

When a 110V test light is connected to the growler, it illuminates if there is a complete circuit through the windings. If there is an open condition, the test light will not illuminate, indicating that there is a fault in one or more of the windings. This method is useful because it not only checks for continuity but also helps to locate the specific area of the fault in the armature by observing the behavior of the light in different sections of the winding.

In contrast, testing with a multimeter on resistance settings can help detect resistance values but might not be as effective for finding opens, particularly in a dynamic test environment. Visual inspection, while helpful in identifying obvious physical damage, may miss internal breaks or faults that do not present visible signs. Applying a high voltage to the windings could potentially lead to damaging the armature if there are already existing weaknesses