PI Manufacturing AC generators - Manual (Page 10)

SECTION 4
INSTALLATION - PART 1
4.1 LIFTING
Incorrect lifting or inadequate lifting
capacity can result in severe personal
injury or equipment damage. MINIMUM
LIFTING CAPACITY REQUIRED IS 750Kg.
Generator lifting lugs should NOT be used
for lifting the complete generator set.
Two lifting lugs are provided for use with a shackle and pin
type lifting aid. Chains of suitable length and lifting capacity
must be used. Lifting points are designed to be as close to the
centre of gravity of the generator as possible, but due to
design restrictions it is not possible to guarantee that the
generator frame will remain horizontal while lifting. Care is
therefore needed to avoid personal injury or equipment
damage. The correct lifting arrangement is shown on the label
attached to the lifting lug. (See sample below).
Single bearing generators are supplied fitted with a rotor
retaining bar at the non-drive end of the shaft.
To remove retaining bar :
1. Remove the four screws holding the sheet metal cover at
the non drive end and remove cover
2. Remove central bolt holding the retaining bar to the shaft
3. Refit sheet metal cover.
Once the bar is removed, to couple the rotor to engine, the
rotor is free to move in the frame, and care is needed during
coupling and alignment to ensure the frame is kept in the
horizontal plane.
Generators fitted with a PMG excitation system are not fitted
with retaining bar. Refer to frame designation to verify
generator type (subsection 1.2)
4.2 ASSEMBLY
During the assembly of the generator to the engine it will be
necessary firstly to carefully align, then rotate, the combined
generator rotor - engine crankshaft assembly, as part of the
construction process, to allow location, insertion and
tightening of the coupling bolts. This requirement to rotate the
combined assemblies exists for both single and two bearing
units.
During the assembly of single bearing units it is necessary to
align the generator's coupling holes with the engine flywheel
holes; it is suggested that two diametrically opposite location
dowel pins are fitted to the engine flywheel, over which the
generator coupling can slide into final location into the engine
flywheel spigot recess. The dowels must be removed and
replaced by coupling bolts before the final bolt tightening
sequence.
While fitting and tightening the coupling bolts it will be
necessary to rotate the engine crankshaft - generator rotor
assembly. Care should be taken to ensure that rotation is
carried out in an approved manner that ensures safe working
practice when reaching inside the machine to insert or tighten
coupling bolts, and that no component of the assembly is
damaged by nonapproved methods of assembly rotation.
Engine manufacturers have available a proprietary tool or
acility designed to enable manual rotation of the crankshaft
assembly. This must always be used, having been
engineered as an approved method of assembly rotation,
engaging the manually driven pinion with the engine flywheel
starter ring-gear.
Before working inside the generator,
during the aligning and fitting of coupling
bolts, care should be taken to lock the
assembly to ensure there is no possibility
of rotational movement.
4.2.1 NO FOOT OPTION
Generators can be supplied without a foot providing the option
for customers own arrangement. For details of mounting this
arrangement, see the general arrangement drawing supplied
with the generator. Alternatively refer to the STAMFORD
factory for a copy of the latest general arrangement drawing
showing the 'NO FOOT OPTION' appropriate to your
generator.
Warning !
Caution !