EXTECH MG500 [11/15] Dc motor test

MG500-en-GB_v1.3 3/17

DC Motor Test

1. Disconnect the motor from the line.

2. To test the brush rigging, field coils, and armature, connect the RED lead to the grounded

motor housing and the GREEN lead to the brush on the commutator.

3. If the resistance measurement indicates a weakness, raise the brushes off of the

commutator and separately test the armature, field coils, and brush rigging by connecting

one lead to each individually, leaving the other connected to the grounded motor housing.

This also applies to DC Generators.

Testing Single Conductor Cables

1. Completely disconnect the cable

under test from its source and

destination.

2. Connect the test leads to the

cable as shown at right.

Testing Multi Conductor Cables

1. Completely disconnect the cable under test from its source and destination.

2. Refer to the diagrams below for three possible tests.

Core Insulation Sheath Covering

EARTH GUARD LINE

Testing one conductor to

all of the conductors

Testing one conductor

to earth

One conductor to all

minus ground

EARTH

LINE

EARTH

GUARD

LINE

EARTH