Beta 1760/OHM Manual Del Usuario Y Operador página 77

connect one megohmmeter lead to the grounded motor housing and the other lead to the brush on
the switch. If the resistance measurement indicates a weakness, raise the brushes off the switch
and separately test the armature, field coils and brush rigging by connecting one megohmmeter
lead to each of them individually, leaving the other connected to the grounded motor housing.
The above also applies to DC Generators.
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