Initial Inspection and Diagnostic Overview

CHECKING THE COMMUTATOR




1. Place the armature on a pair of V-blocks, and check the run - out by using a dial gauge.

Standard value
Armature run - out: 0.05 mm (0.002 in.)

Limit
Armature run - out: 0.1 mm (0.0039 in.)




2. Check the outer diameter of the commutator.

Standard value
Outer diameter of the commutator: 29.4 mm (1.157 in.)

Limit
Outer diameter of the commutator: 28.4 mm (1.118 in.)





3. Check the depth of the undercut between segments.

Standard value
Depth of the undercut between segments: 0.5mm (0.020 in.)

Limit
Depth of the undercut between segments: 0.2mm (0.079 in.)