Hobart 120CU20, Operation And Maintenance Manual With Illustrated Parts List

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OM-2228 / Operation and Maintenance Manual
120CU20 / Series 500120 / 400 Hz. Generator Set
October 15, 2013 Chapter 2-2
Page 14
7) Generator Maintenance.
The 400 Hz generator requires no maintenance or service other than periodic cleaning. The unit is
brushless and has bearings that are permanently lubricated and sealed.
a) Cleaning.
The generator may be cleaned by careful use of compressed air and/or a good, SAFE commercial
cleaner. Steam cleaning of the generator is not recommended because the use of steam and harsh
chemical compounds may result in damage to insulation and other generator components.
CAUTION
Do not use a flammable solvent. Be sure the unit is completely dry before operating.
b) Adjustment.
The generator itself requires no adjustment. Adjustment procedures for generator controls are
covered in Section 2-3.
8) Drive Belt.
a) General.
The engine cooling fan, alternator, and water pumps are driven by one serpentine belt, which must be
replaced if worn or damaged.
b) Preparation for Belt Check and Adjustment.
All driven assemblies must be securely mounted in operating position before checking belt tension.
c) Checking Belt Tension.
CAUTION
Checking the tension and changing the serpentine belt should only be performed with
the engine off.
Check belt tension every 1000 hours, or once year, whichever comes first. A belt that is too tight is
destructive to bearings of the driven part. A loose belt will slip and cause inefficient operation of the
part being driven as well as wear to the belt.
CAUTION
Inspect and replace the belt if it has unacceptable cracks, is frayed, or has pieces of
material missing.
Belt tension may be checked by hand. To do so, manually depress the belt with an index finger to
determine the amount of belt deflection obtained. When a force is applied at a point halfway between
pulleys on the longest span of a belt, there should be no more than 1/2 inch of deflection attained.
Refer to the engine manufacturer’s operation manual for checking belt tension and changing worn
belts.