Usage:
1. Exciter and regulator cover.
2. Field pole (1800 rpm generators have four field poles while 1200 rpm generators have six field poles).
3. Rotor shaft hub.
4. Engine flywheel.
5. Bearing retainer and brush yoke.
6. Brush holder.
7. Collector ring.
8. Generator support (This is also the rear engine support on all electric sets except the D379, G379, D398, G398 electric sets).
9. Stator windings (armature).
10. Generator fan.
11. Coupling flexible drive discs.
CUTAWAY SRSE GENERATOR
Generator Drive Removal And Installation
1. Remove the generator from the engine. See the covering topic in the engine Service Manual.
2. Remove the bolts (2) securing the drive assembly (3) to the rotor shaft hub (5).
PREPARING TO REMOVE THE GENERATOR DRIVE
1. Eyebolt. 2. Bolt. 3. Drive assembly. 4. Bar.
3. Insert an eyebolt (1), secure it with a nut (6) and attach a suitable hoist.
4. Insert a bar (4) in one of the drive assembly holes, as illustrated, for balancing and guiding. Then remove the drive assembly from the generator, being careful not to damage the coupling flexible discs (8).
REMOVING THE GENERATOR DRIVE ASSEMBLY
5. Rotor shaft hub. 6. Nut. 7. Shims. 8. Coupling flexible discs. 9. Generator fan.
5. Inspect the shims (7) for damage, but do not remove them unless replacement is necessary. See the topic, SINGLE BEARING GENERATOR ALIGNMENT, for addition or removal of shims.
6. Inspect the generator fan (9). If the fan is damaged, it should be replaced. A few bent fan blades can sometimes be straightened if the alignment or the balance of the fan does not change when a blade is straightened.
7. Install the generator fan and drive assembly in the reverse order of removal.
Bearing Removal And Installation
1. Remove the screens (3) over the ventilation openings.
2. Remove the brushes from the brush holders and remove the bolts (4) which secure the bearing retainer and brush yoke to the cover.
3. Remove the bolts (2) which secure the rear cover (1) to the generator.
NOTE: Insert a strip of cardboard or wood under the rotating field to prevent damage to either the rotating field or the stator when the rear cover is removed.
PREPARING TO REMOVE THE REAR COVER
1. Rear cover. 2. Bolt. 3. Screen. 4. Bolt.
4. Install two guide screws (5) where bolts (2) have been removed and two forcing bolts (6) in the threaded holes in the rear cover as illustrated. Using the two forcing bolts, push the rear cover from the generator.
REAR COVER REMOVAL
5. Guide screws. 6. Forcing bolts.
NOTE: On large generators, a suitable hoist should be attached to the rear cover to support the cover when it is removed.
PREPARING TO REMOVE BEARING
7. Bearing retainer and brush yoke. 8. Lock. 9. Spanner nut.
5. Push the bearing retainer and brush yoke (7) away from the bearing. Bend the lock (8) from the notch in the spanner nut (9) and remove the nut.
6. Remove the bearing (12) from the rotor shaft, using a 6F25 Service Press with a 5F7343 Bearing Pulling Attachment, an 8B7548 Push Puller, two 8B7550 Legs 4.5 in. (114 mm) long, two 5F7342 Adapters and a step plate of suitable diameter.
BEARING REMOVAL Remove
10. Spacers. 11. Bearing. 12. Puller bolt.
NOTE: Use two spacers (10), with 1 in. (25 mm) inside diameter and 2 in. (51 mm) length, to provide clearance for the puller bolts (12). Use extreme care while adjusting the puller bolts in the Bearing Pulling Attachment to prevent the bearing retainer and brush yoke from being pushed back and damaging the collector ring.
7. Inspect the bearing for damage or wear and replace it if necessary.
8. Install the bearing in reverse order of removal.
NOTE: The bearing should be heated in oil [not to exceed 240°F (116°C)] to facilitate installation. The shielded side of the bearing must be toward the field poles. 350 kW and 500 kW units have an inside bearing cap and slinger and have no shield on the bearing.
9. Install the rear cover, secure the bearing retainer and brush yoke to the cover and install the brushes in their proper slots in the brush holder. The brush springs should be correctly positioned so they do not rub on the brush wires.
10. Lubricate the bearing according to the Operation and Maintenance Instructions.
Bearing Retainer And Brush Yoke Assembly Removal And Disassembly
1. Remove the generator end cover and bearing.
2. Mark the wires (3) and disconnect them from the brush holder (1).
PREPARING TO REMOVE BEARING RETAINER AND BRUSH YOKE ASSEMBLY
1. Brush holder. 2. Bearing retainer and brush yoke assembly. 3. Wires.
3. Remove the bearing retainer and brush yoke assembly (2) from the rotor shaft.
REMOVING BRUSH HOLDERS
4. Brush holder. 5. Clamping bolt. 6. Insulation tubes.
4. Loosen the clamping bolts (5) at both ends of each brush holder (4). Remove the brush holders and inspect all four of the insulation tubes (6) for cracks or other damage. Replace insulation tubes if damaged.
5. To remove a brush tensioning spring (9), first remove the cotter pin from one end of pin (8), then push the pin from the brush holder and remove the spacer (7) and the spring (9).
REMOVING BRUSH SPRING
7. Spacer. 8. Pin. 9. Spring. 10. Brush.
NOTE: If the spring tension is less than specified in the brush chart, install new springs.
6. Disconnect the brush wire from the brush holder and remove brush (10).
NOTE: If a brush is chipped, has a loose wire connection, is unevenly worn, or is worn to the minimum length specified in the brush chart, install a new brush.
7. Place the spacer (7) and the spring (9) into the brush holder and insert the pin (8) so the inner end of the spring (12) fits into the slot (11) in the pin.
ASSEMBLING SPRING
11. Slot in pin. 12. Inner end of spring.
8. Install the brush holders (4) on the insulation tubes (6) of the bearing retainer and brush yoke (2), but do not tighten the clamping bolts (5) at this time. Connect the brush wire leads.
NOTE: While the bearing retainer and brush yoke assembly are removed from the rotor shaft, inspect the contacting surfaces of the collector rings. If the surfaces are discolored, either green or blue, they should be cleaned. Cleaning collector rings is covered in the Operation and Maintenance Instructions. If the rings have spotted blotches, or are rough and pitted, the rotor assembly can be removed and the rings turned and polished in a lathe. The rings can be turned without removing the rotor assembly from the generator by using a 9H2436 Collector Ring Turning Tool.
9. Install the bearing retainer and brush yoke assembly (2) on the rotor shaft. The longer insulation tubes (6) should be to the left when facing the rear of the generator. Connect the marked wires (3) to the brush holder.
10. Install the bearing, the generator rear cover, and secure the bearing retainer and brush yoke assembly to the rear cover.
11. Move the generator rotor as far to the rear of the generator as possible (the generator bearing has end play clearance in the bearing retainer). Insert the brushes in their proper slots and adjust the brush tensioning spring. See the brush spring tension chart for correct brush spring tension.
12. Move the brush holders, on the insulation tubes, so each brush will contact the collector ring surface near the front of each collector ring (toward the field poles) and tighten the clamping bolts.
NOTE: Remove all protecting strips of cardboard or wood from the generator before ventilation opening screens are installed.
Rotating Field Removal And Installation
1. Remove the generator rear cover and bearing, mark and disconnect the wires connected to the brush holders.
PREPARING TO REMOVE ROTOR SHAFT ASSEMBLY
1. Field pole. 2. Stator winding. 3. Shaft.
NOTE: The threaded end of the shaft (3) should be wrapped to protect the threads while the rotor shaft assembly is being removed (or installed) from the generator.
2. Using a suitable hoist attached to the hub end of the rotor shaft and a pipe (4) (approximately four feet long) slipped over the bearing end of the shaft (3), as illustrated, carefully remove the rotor shaft assembly from the generator.
NOTE: Put several strips of cardboard or wood between the field pole (1) and the stator winding (2) to protect the field pole and stator from damage when the rotor shaft assembly is being removed (or installed).
REMOVING ROTOR SHAFT ASSEMBLY
4. Pipe.
3. Inspect all parts for wear or damage and replace parts when necessary. Install in reverse order of removal and make certain the protective strips have been removed before the generator is to be operated.
Field Poles Removal And Installation
1. Remove the rotating field assembly from the generator.
2. Bend the locks and remove the bolts and field pole supports (5).
NOTE: Construct a template (1) of the correct field pole diameter before removing the bolts from the field pole support.
TEMPLATE TO CHECK HEIGHTS OF BOLT HEADS
1. Template.
3. The wires (2) should be marked for reconnection; then disconnect these wires from each end of the field poles (7).
NOTE: The field poles may be removed without disturbing the collector rings (6).
PREPARING TO REMOVE FIELD POLES
2. Wires. 3. Weights. 4. Wedge. 5. Field pole support. 6. Collector ring. 7. Field pole.
NOTE: Each field pole (7) is dovetailed in spider (8) and is secured by a wedge (4) from each end. Each wedge is welded to prevent it from loosening.
PREPARING TO REMOVE FIELD POLE
7. Field pole. 8. Spider.
4. Cut the welds holding the wedge on the collector ring end of the field poles (7) and spider (8).
5. Fabricate a tool for removing the field pole.
FIELD POLE REMOVAL TOOL
9. S1575 Bolt, 3/4 10NF, 3.0 in. (76 mm) long. 10. Adapter 8B7555. 11. 2B6030 Bolt, 5/8-11 NF, 6.0 in. (152 mm) long.
6. Grind the head of bolt (11) so it will slide through the dovetail in spider (8).
7. Grind the head of bolt (9) so it has a center pivot point.
8. Install removal tool (12) to remove the field poles.
PREPARING TO REMOVE FIELD POLE
12. Removal tool.
9. Push the field pole until it is free and remove the wedge on the collector ring end.
10. Slide the field pole from the spider assembly.
11. Clean the mating surfaces of field pole (7) and spider (8). Install the field pole dovetail in the spider. One wedge will still be welded in place when the field pole is removed. If this wedge is damaged, cut the weld and replace the wedge.
12. Install wedge (4), small end first, into the end of the dovetail and drive the wedge in as far as possible.
REMOVING FIELD POLE
INSTALLING FIELD POLE
4. Wedge.
13. Weld the large end of the wedge to secure it in place.
14. Install the field pole supports (5).
| NOTICE |
|---|
Before locking the bolt heads, use template (1) to make certain the bolt heads are below the outer circumference of the field poles. |
15. Connect the wires (2) that were marked for reconnection in Step 3.
16. The rotating field assembly must be balanced whenever any part of the rotating field assembly has been disturbed or replaced. The use of a balancing machine is necessary to determine the location and number of weights (3) required on each field pole to obtain proper balance.
Statically Excited Exciter Regulator For SRSE Generators
5L6993, 5L7041 and 5L7127 Exciter Regulator Assemblies, used with the SRSE generators within a basic kilowatt size are mechanically the same for units rated 120/208 volt, 240-480 volt, 2400 volt, 60 cycle and 200-400 volt, 50 cycle. Assemblies for parts service are factory wired for generators rated 240-480 volt, 60 cycle or 200-400 volt, 50 cycle. When a replacement assembly is to be used on units rated 120/208 volt and 2400 volt, 60 cycle, it is necessary to reconnect four inside connections as follows.
Generators rated at 240-480 volt, 60 cycle and 200-400 volt, 50 cycle.
NOTE: It is necessary to connect a total of eight outside wires as per the wiring diagram attached inside the exciter regulator cover.
A. Voltage droop transformer.
B. Voltage droop control switch.
C. Saturable reactor.
D. Full-wave rectifier.
E. Stator.
F. Rotating field.
H. Voltage level resistor.
J. Voltage level rheostat.
N. Power rectifier.
P. Heat sink.
Q. Voltage control choke.
R. Exciter reactor.
S. Trimmer resistor.
T. Trimmer choke.
U. Relay N.C.
240-480 AND 200-400 VOLT GENERATORS 3 PHASE
SRSE GENERATOR
B. Voltage droop control.
TERMINAL BOARD
1. Connect wires from voltage droop switch (B) to terminals 1 and 5 on the terminal board.
2. Connect wires (15), (16), (17) and (18), from generator stator (E), to the corresponding terminals on the terminal board.
SRSE GENERATOR
E. Generator stator. F. Rotating field.
3. Connect wire C2 from generator rotating field (F), to terminal (19) on the terminal board.
4. Connect wire C1, from generator rotating field (F), to terminal (20) on the terminal board.
Generators Rated at Volt or 2400 Volt, 60 Cycle
1. It is necessary to make eight outside and four inside wire connections as per the wiring diagram attached inside the exciter regulator cover. Make the eight outside connections as shown in the topic, GENERATORS RATED AT 240-480 VOLT, 60 CYCLE AND 200-400 VOLT, 50 CYCLE.
A. Voltage droop transformer.
B. Voltage droop control switch.
C. Saturable reactor.
D. Full-wave rectifier.
E. Stator.
F. Rotating field.
H. Voltage level resistor.
J. Voltage level rheostat.
N. Power rectifier.
P. Heat sink.
Q. Voltage control choke.
R. Exciter reactor.
S. Trimmer resistor.
T. Trimmer choke.
U. Relay N.C.
120/208 VOLT GENERATORS 3 PHASE (SINGLE VOLTAGE)
2. Remove wire (1) from terminal H on saturable reactor (C) and connect the wire to terminal L on the reactor.
Three wires H3 from exciter reactors R are connected with wires passing to power rectifier (N). Two of the three wires H3 are also connected to wires from the negative side of relay (U). Disconnect wires H3 at their junctions with the other wires and reconnect each junction to exciter reactor tap wires H2. Tape the terminal end of each wire H3.
REWIRING SATURABLE REACTOR
1. Wire. C. Saturable reactor.
EXCITER REACTORS REWIRED