BOLT 6V8004 - Caterpillar

Construction Of The Generator
The SR4 HV and SR4B HV generators are described in this manual. SR4 HV and SR4B HV generators are brushless revolving field type generators. The SR4 HV and SR4B HV generators have close coupled construction. The SR4 HV generators are manufactured in two frame sizes: 2500 series and 2900 series. The SR4B HV generators are manufactured in three frame sizes: 2400 series, 2600 series and 2800 series. The generator's excitation current is supplied by a rotating exciter. This exciter is brushless and this exciter is directly connected to the rotating shaft. SR4 HV and SR4B HV generators can be supplied with various controls. These controls are designed to provide exact power requirements. Normally, controls are separately shipped. In some cases, the customer may request special packaging. In these cases, controls can be packaged in the following ways:
a separate control box that is mounted on the wall
a switchgear that stands aloneGenerators are supplied with permanent magnet generators (PMG). Permanent magnet generators provide excitation power to the voltage regulator under the following conditions:
normal running conditions
short circuit conditions
electromagnetic interferenceGenerators are supplied with a mounted terminal box that is designed to accommodate the high voltage connections to the load. A separate low voltage compartment in this box is used to accommodate accessory connections to the following components: Resistance Temperature Detectors (RTD), space heaters, exciter and permanent magnet generators.The basic generator includes the following items:
stator
rotor
brushless exciter
permanent magnet generator (PMG) The generator frame is fabricated of heavy steel members. These members are welded to the endbell or these members are attached to the pilot ring of the bearing bracket. The feet are attached to the frame. This simplifies installation and alignment. Lifting eyes are fastened to the frame in order to lift the generator with an overhead hoist.
Improper lift rigging can allow unit to tumble causing injury and damage.
Do not use the engine lifting eyes to remove the engine and generator together.
Construction Of The Stator
The generator stator is constructed of fabricated bars and steel plates. The stator is machined to tolerance in order to provide alignment with the rotor. The stator is constructed of steel laminations that have the following features: no orientation, silicon steel construction and core plated insulation on both sides. The stacked laminations are offset in order to reduce harmonic distortion that can be caused by the slots. The laminations are secured under pressure by clamping plates. Therefore, there is no welding on the laminations. This type of lamination is used for the following reasons:
reduce core loss.
reduce the rise in temperature of the machine.
improve efficiency.There are stator windings that overhang the laminations of the stator. These windings are insulated between phases. Surge ropes are used in order to support the winding's overhang. The windings are braced in order to withstand single-phase fault conditions and three-phase fault conditions.The stator windings are formed coils. The windings are inserted into the slots of the stator. The entire assembly is then vacuum pressure impregnated with 100% epoxy resin.
Illustration 1 g00570897
Generator