Parts Replacement & Testing: Armature
- Check commutator to shaft (or core) for short circuit with 110 volt AC test lamp. Test lamp should not light; however, slight glow may occur due to dampness.
- Check armature coils for short circuit between windings using an armature growler. Check commutator for pits, burns or rough surface.
- If out of round exceeds 0.002" (0.05 mm), or grooves or burned spots cannot be removed with fine crocus cloth, commutator must be turned. Undercut insulation between commutator bars to a maximum depth of 0.024" (0.6 mm).NOTE: Never use emery cloth or a file on commutator; turn on a lathe only.