Onan UF Series Instruction Manual And Parts Catalog page 73

S E R V I C E D I A G N O S I S
15
Following is a list of troubles that may be experienced in the operation
of the generator. Also listed are the possible causes and usual rem-
edies for getting the generator back into proper efficient operation.
POSSIBLE CAUSE REMEDY
POOR COMMUTATION OR ARCING AT THE GENERATOR BRUSHES
Brushes out of neutral position.
Brushes not seating properly.
Generator heavily overloaded.
Brushes binding in holder.
Brush tension insufficient.
Brushes worn too short.
Brush tension unequal.
Wrong type brush.
Loose commutator bars.
High mica.
Commutator out of round.
Commutator surface dirty or
oily.
Turn brush ring until the identify-
ing marks are aligned.
Sand the brush to the proper contour.
If the AC or DC amperage is more
than stated on the generator name-
plate, remove part of the load.
Clean each brush and holder.
Replace brush springs.
Replace brushes.
Replace weak brush springs.
Replace with correct type and make
of brush and spring.
Replace with new armature.
Undercut the mica.
True the commutator in a lathe.
Clean the commutator.
OVERHEATING OF GENERATOR
Windings and parts covered
with dirt and oil.
Overloaded.
Short circuit or grounded
circuit in the field winding or
armature winding.
Clean generator.
Check load or output of generator.
Replace defective parts.