When performing a cranking motor no load test we may have three types of test results. Match the possible causes on the left with the test results on the right.

Question 1

electrical short in armature

Answer 1

High current draw, low free speed

Question 2

electrical short in field winding

Answer 2

High current draw, high free speed

Question 3

electrical open in the field winding

Answer 3

Low current draw, low free speed

Question 4

broken brush springs, worn brushes

Answer 4

Low current draw, low free speed

Question 5

bent armature shaft causing binding

Answer 5

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High current draw, low free speed

Question 6

field winding grounded to the case

Answer 6

High current draw, low free speed

Question 7

input terminal grounded to the case

Answer 7

High current draw, low free speed

Question 8

positive brush holder grounded to case

Answer 8

High current draw, low free speed

Question 9

open in armature winding

Answer 9

Low current draw, low free speed

Question 10

armature bearings worn

Answer 10

High current draw, low free speed

Question 11

armature bearings tight

Answer 11

High current draw, low free speed

Question 12

seized armature bearings

Answer 12

High current draw, low free speed

Question 13

loose pole shoes

Answer 13

High current draw, low free speed