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DC Compound Dual Voltage Motors
DC Compound dual voltage motors normally have 2 separate shunt fields, which are in parallel
with the armature field and 1 series field, which is
in series with the armature field. For testing DC
compound dual voltage motors at the motor each
of the coils can be tested by themselves.
The armature leads are normally labeled A1 & A2,
the field coil leads for the shunt field 1 coil are
normally labeled F1 & F2, the field coil leads for
the shunt field coil 2 are normally labeled F3 & F4,
and the field coil leads for the series field coil are normally labeled S1 & S2.
It is recommended to take the shunt field winding 1 first F1 & F2 for DC1, the shunt field winding
2 second F3 & F4 for DC2, the series winding third S1 & S2 for DC3 and the armature winding
last A1 & A2 for DC4.
Note: Always remeasure the armature windings to look for carbon build up.
Since the Field leads are parallel to the armature windings, separate IRG measurements are
taken from the field coils to Ground or the frame and the armature coils to ground or frame a
third Insulation resistance measurement is taken from the field coil to the armature coil.
INS1 = field windings to ground
INS2 = armature windings to ground
INS3 = field winding to armature winding
STATIC readings for DC Shunt Dual Voltage Motors
DC1 = Series coil
DC2 = Field Coil 1
DC3 = Field Coil 2
DC4 = Armature Coil
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