Onan NH User Manual

Testing Armature for Grounds:Touch armature shaft or
core and the end
of each commutator bar with a pair of
ohmmeter leads (Figure
41). If the ohmmeter reading is
low, it indicates a grounded armature. Replace a
grounded armature.
Testing Field Coils for Open Circuifs: Place one lead
on the connector and the other on a clean spot on the
brushholder (Figure
43). A high ohmmeter reading
indicates the field coil is open. Check the other three
brushholders in the same manner.
COMMUTATOR.
..
~-_____ ._
FIGURE 41. ARMATURE GROUND TEST
lnspecfing for an Open Circuit in Armafure:The most
commutator riser bars. Inspect for loose connections
on the points where the conductors are joined to the
commutator bars.
Testing Field Coils for Grounds: Place one lead on
the connector and the other on a clean spot
on the
frame after unsoldering the shunt field coil wire (Fig-
ure42).Alowohmmeter reading indicatesagrounded
field either at the connector or in the windings.
likely place to check for an open circuit is at
the
FIGURE 43. FIELD COIL OPEN CIRCUIT TEST
Testing CommufaforRunouf: Place armature in a test
bench and check runout with a dial indicator (Figure
44). When commutator runout exceeds 0.004 inch
(0.102 mm), reface the commutator.
.
FIGURE 42. FIELD COIL GROUND TEST FIGURE 44. CHECKING COMMUlTOR RUNOUT
36

Onan NH Specifications

General

Brand	Onan
Model	NH
Category	Engine
Language	English