Specifications

84
An external growler shown in Fig. 6.15 is an electromagnetic device that is used to detect
and locate grounded, shorted and open coils in an armature. This growler consists of a coil
wound around an iron core and is connected to a 240 volt AC line. The core is generally H
shaped and cut out on to so that the armature will fit on it, as shown in Fig. 6.16.
Fig. 6.16
When an alternating current is applied to the growler coil, the voltage will be induced in the
armature coils by transformer action.
Internal growler : An internal growler, such as the one used for stators, may be used for
armatures as well. These are made with or without built-in feelers.The growler with a built-in
feeler has a flexible blade attached to the growler so that a hacksaw blade or similar instrument
is not necessary. This type is especially desirable in smaller stators that have no room for a
separate feeler. Fig. 6.17 shows an internal growler with a separate feeler, used for large
armatures.
Fig. 6.17 Internal Growler