Northern Lights PX-300K1 Series A.C. Generator, Руководство оператора и каталог запасных частей

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OPX300K1 09/09
11
Maintenance
BEARING INSPECTION
For bearing inspection, make sure that there is no
abnormal sound during normal running and no
over heating. Greasing is not necessary for generators
using the double seal type ball bearings, but these will
need to be replaced after every 10,000 hours of operation
(see
PARTS REPLACEMENT METHOD
).
INSULATION RESISTANCE MEASUREMENT
If the generator has not been used for a long time, check
the insulation resistance of each lead wire at 500V with a
megger.
It is usually enough to check only the stator winding. In
order to prevent damage to the AVR, disconnect it. If the
measured insulation resis tance value is above 2 M ohms,
there is no problem, but if it is lower than that, check to
see if the inside of the generator is wet or dirty. If dust
has accumulated, blow it out with dry compressed air.
Wipe off oil stains with a cloth. If the generator is damp,
dry it and recheck.
ROTATING RECTIFIER ASSEMBLY
The rotating rectifi er assembly needs little attention. Clean
off dust and oil stains periodically. In the unlikely event
that it becomes necessary to replace the diode elements
and surge absorber elements. Refer to
PARTS
REPLACEMENT METHOD
, Point 2.
PARTS REPLACEMENT METHOD
1. Bearing Replacement:
a. In order to replace the bearing, fi rst remove the
bearing holder housing on the end of the
generator. Loosen and remove the four housing
bolts. Remove the bearing holder gently since
there is a risk that the rotor could fall and damage
the exciter rotor or the exciter stator.
Figure 6. Pilot Length
b. Using a bearing puller, extract bearing from
shaft.
c. When installing a new bearing, place a steel pipe
on the inner race surface, and fi t the bearing by
tapping it lightly with a hammer.
Figure 7. Bearing Puller
Note: Absolutely do not apply pressure to outer race
of the bearing during insertion.