Generac Power Systems 53187 - Manual (Page 22)

Components Inspection
REAR BEARING COVER AND GASKET:
Clean the Beeuing Cover in a suitable non-flam m able
com m ercial cleaner. Blow dry w ith com pressed air.
Inspect the Cover for obvious dam age, clogged air slots,
etc. Replace, if necessary. Inspect gasket, replace if
dam aged or defective.
SECTION 1.4- MAJOR COMPONENTS
(UNITS WITH 10 INCH STATOR)
REAR BEARING CARRIER;
The Rear Bearing Carrier is an alum inum casting.
Clean the casting and blow dry w ith air. Inspect carefully
for cracks, dam age. An insert is pressed into the Bear­
ing Carrier center bore, to accom m odate the Rotor
bearing. Use an inside m icrom eter to check the inside
diam eter of the insert. Replace the Bearing Carrier if the
insert inside diam eter is not w ithin the follow ing:
J
PARTI
THE REVOLVING FIELD AC GENERATOR
2.834-2.836 inches (71.996-72.012m m )
and Testing (Continued)
the Rotor w ith dry, heated airfor several hours. DO NOT
EXCEED 185* F. (85* C.). if Insulation resistance is still
low after drying, replace the Rotor Assem bly.
FAN AND RING GEAR ASSEMBLY:
The FAN, DRIVE HUB, COUPLING PLATE and
RING GEAR are assem bled and balanced as a unit.
Clean and inspect parts, replace the entire assem bly if
necessary.
BRUSH HOLDER AND BRUSHES:
Inspect both brush holders and both sets of brushes.
Look for cracks, excessive w ear, cracks, chipping, etc.
Replace any dam aged brush holder. Brushes should be
replaced as a com plete set
Inspect brush leads No. 1 and 4. Replace any
dam aged or defective brush lead.
STATOR ASSEM BLY:
Clean the stator can exterior surfaces w ith a soft
brush or cloth. Use clean, dry low pressure air (25 psi
m axim um ) to clean the stator. Use an ohm m eter to test
the resistance of Stator AC pow er and excitation w ind­
ings. Use an insulation resistance tester (m egohm m eter
or Hi-Pot tester) to check condition of Stator insulation
(see Section 1.8). If Stator insulation fails the test, the
Stator m ay be dried by blow ing w arm , dry air across it
for several hours. DO NOT EXCEED 185* F. (85* C.). If
insulation resistance is still low after drying, replace the
Stator.
BLOW ER HOUSING:
Clean w ith a com m ercial solvent that is suitable for
use w ith alum inum . Inspect the Housing carefully for
cracks, dam age, etc. Replace, if necessary.
ROTOR ASSEMBLY:
Clean w ith dry, low pressure air (25 psi m axim um ).
Test Rotor w inding resistance w ith an ohm m eter. Check
Rotor bearing for binding, seizing, roughness. If the
bearing is defective, replace the Rotor assem bly. In­
spect the keyw ay in the tapered shaft for w ear, dam age.
If slip rings are dull or tarnished, clean w ith fine
sandpaper. Use an insulation resistance tester
(m egohm m eter or Hi-Pot tester) to test for insulation
breakdow n (see Section 1.8). If resistance is low , dry
Generator Reassembly
Reassem ble the generator in the reverse order of
disassem bly. The reassem bly process requires a great
deal of care. All com ponents m ust be properly aligned
and retained. Tighten all fasteners to the recom m ended
torque values. Follow ing reassem bly, perform an opera­
tional test of the unit.
Components In Generator Control Panel
INTRODUCTION:
The follow ing AC generator com ponents are
m ounted on or housed in the generator control panel:
□ Voltage Regulator Assem bly.
□ An AC Circuit Breaker (CB1 and CB2).
□ Exdtation Circuit Breaker (CB4).
□ A field boost circuit.
In addition to the above AC generator com ponents
housed in the control panel, aTHERM AL PROTECTOR
is physicaliy im bedded in the w ire w indings of the Stator
Assem bly.
Other com ponents are housed in the control panel,
as w ell. How ever, these com ponents are part of the
engine's DC control system and w ill be discussed in
PART 5, "ENGINE ELECTRICAL SY STEM ".
PAGE 1.4-4