TM 9-4940-549-14&P
a.
Alternating Current Stator.
(1)
Tag and disconnect motor leads at terminal board 5CW5063.
(2)
Use a multimeter to test continuity between stator leads B and
lB, 2B and 3B, A and 1A, 2A and 3A, C and lC, 2C and 3C.
If continuity is not indicated, the alternating current stator
must be replaced.
Use a multimeter to test insulation resistance between the dyna-
(3)
motor-welder frame and motor leads A and 2A, B and 2B, C
and 2C. If any reading on the multimeter is less than 0.5 meg-
ohm, faulty insulation is indicated, and dynamotor-welder must
be removed for further testing.
(4)
Use a multimeter to test insulation resistance between stator
lead lB and leads 3B, C, 2C, A, 2C, 2A; between stator lead
3B and leads C, 2C, A, 2A; between stator lead C and leads
2C, A,2A; between stator lead 2C and leads A, 2A; between
stator leads A and 2A. A reading of less than 0.5 megohm
indicates faulty insulation and the dynamotor-welder must be
removed for further testing.
b.
Revolving Fields.
(1) Raise the revolving field brushes from the sliprings.
(2) Use a multimeter to test resistance between the two slip rings.
A resistance greater than 10 percent above or below 45 ohms
indicates faulty winding and the rotor must be removed for fur-
ther testing.
(3) Use a multimeter to test resistance between either slipring and
the rotor shaft. A resistance reading of less than O.5 megohm
indicates faulty insulation and rotor must be removed for fur-
ther testing.
c.
Exciter Armature.
(1) Raise the exciter brushes from the exciter armature.
(2) Use a multimeter to test insulation resistance between the rotor
shaft and one of the exciter commutator bars; repeat this using
at least two other bars around the commutator. If any reading
is less than 0.5 megohm, faulty insulation is indicated and the
dynamotor-welder must be removed for further testing.
d.
Exciter Field.
(1) Tag and disconnect exciter field leads at terminal board 5CW5063.
