SR4 Generator with VR3 or VR4 Voltage Regulator Caterpillar

Removal Procedure

Remove The Exciter Field and Remove The Exciter Armature

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Illustration 1	g00853527
Side And Rear Access Panels

1. Remove the side and rear access panels from the generator.

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Illustration 2	g00853531
Voltage Regulator (1) Wires F1 and F2

2. Disconnect wires F1 and F2 (1) from the first termination point. These wires terminate at the voltage regulator or at a terminal strip.

   For permanent magnet pilot excited generators, disconnect wires 26, 28, and 30 from the first termination point. These wires first terminate at fuses. These fuses are located on a terminal strip or these fuses are located in the harness.

   Pull the disconnected wires from the harness bundles and place the disconnected wires near the exciter field.

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Illustration 3	g00619571
Two-Diode Rectifier Blocks (Three Pieces)

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Illustration 4	g00619585
Three-Diode Rectifier Block

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Illustration 5	g00854996
(2) Wires (3) Allen head screws (4) Rectifier Block (5) Mounting Assembly

3. Various rectifier blocks and mounting hardware are used. The rectifier blocks and the mounting plate must be removed in order to remove the exciter. Disconnect the two generator main field leads from the rectifier blocks. Also, disconnect the three exciter leads from the rectifier blocks.

   For generators with the six-diode rectifier block (4), remove two allen head screws (3) which fasten the six-diode rectifier block and mounting assembly (5) to the rotor shaft. Remove the six-diode rectifier block and mounting assembly (5) .

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Illustration 6	g00855818
Generator With Outboard PM Pilot Exciter (6) Bolts (7) Mounting Assembly (8) Retainer

4. On generators with an outboard PM pilot exciter, perform the following procedure:

   1. Remove four bolts (6) which fasten retainer (8) and mounting assembly (7) to the rotor shaft.

   2. Remove retainer (8) and mounting assembly (7). Ensure that the diode rectifier blocks remain attached.

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Illustration 7	g00855821
Generator With Outboard PM Pilot Exciter (9) Bolts (10) Rotating Pilot Exciter Field (11) Stationary Pilot Exciter Armature

5. On generators with an outboard PM pilot exciter, perform the following procedure:

   Note: The magnetism between pilot exciter armature (11) and pilot exciter field (10) is very strong. The components may come off at the same time.

   1. Remove four bolts (9) which fasten stationary pilot exciter armature (11) to the generator.

   2. Remove stationary pilot exciter armature (11) and rotating pilot exciter field (10) .

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Illustration 8	g00855822
Shroud and Exciter Field (12) Shroud (13) Exciter Field (14) Bolts

6. If equipped, remove four bolts (14) which fasten shroud (12) and exciter field (13) to the generator. Remove shroud (12) (if equipped) and exciter field (13) from the generator.

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Illustration 9	g00855826
Retainer and Exciter Armature (15) Exciter Armature (16) Retainer (17) Bolts

7. Four bolts (17) and a retainer (16) are used to fasten exciter armature (15) to the rotor shaft. Remove the four bolts and remove the retainer. While the retainer is being removed, carefully pass the generator leads through the retainer's opening. Remove exciter armature (15) from the rotor shaft.

   Note: If the exciter armature cannot be pulled from the rotor shaft by hand, then a pulling tool must be used. Use a pulling tool that will not damage the armature windings.

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Illustration 10	g00855827
Generator with Outboard PM Pilot Exciter (18) Bolt (19) Exciter Field

8. On generators with an outboard PM pilot exciter, perform the following procedure:

   1. Remove four bolts (18) which fasten exciter field (19) to the generator.

   2. Remove exciter field (19) .

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Illustration 11	g00855828
Generator With Outboard PM Pilot Exciter (20) Exciter Armature (21) Spacer

9. On generators with an outboard PM pilot exciter, perform the following procedure:

   1. Carefully slide spacer (21) off the rotor shaft.

   2. As the spacer is slid off the rotor shaft, ensure that the spacer clears the exciter leads.

   3. Remove exciter armature (20) from the rotor shaft.

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Illustration 12	g00855830
Generator With Inboard PM Pilot Exciter (22) Pilot Exciter Armature (23) Pilot Exciter Field (24) Spacer (25) Bolts

Note: The magnetism between pilot exciter armature (22) and pilot exciter field (23) is very strong. The components may come off at the same time.

10. Slide spacer (24) off the rotor shaft.

11. Remove four bolts (25) which fasten stationary pilot exciter armature (22) to the generator.

12. Remove stationary pilot exciter armature (22) and rotating pilot exciter field (23) .

Installation Procedure

Install The Exciter Field and Install The Exciter Armature

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Illustration 13	g00855830
Generator With Inboard PM Pilot Exciter (22) Pilot Exciter Armature (23) Pilot Exciter Field (24) Spacer (25) Bolts

1. On generators with an inboard PM pilot exciter, perform the following procedure:

   1. Slide stationary pilot exciter armature (22) and rotating pilot exciter field (23) over the rotor shaft.

   2. Use four bolts (25) in order to fasten the stationary pilot exciter armature (22) to the generator.

   3. Slide spacer (24) on the rotor shaft.

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Illustration 14	g00855828
Generator With Outboard PM Pilot Exciter (20) Exciter Armature (21) Spacer

2. On generators with an outboard PM pilot exciter, perform the following procedure:

   1. Slide exciter armature (20) on the rotor shaft.

   2. As the spacer is slid on the rotor shaft, ensure that the spacer clears the exciter leads.

   3. Carefully slide spacer (21) on the rotor shaft.

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Illustration 15	g00855827
Generator with Outboard PM Pilot Exciter (18) Bolt (19) Exciter Field

3. On generators with an outboard PM pilot exciter, perform the following procedure:

   1. Place exciter field (19) on the generator.

   2. Use four bolts (18) to fasten the exciter field to the generator.

4. Slide exciter armature (15) on the rotor shaft.

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Illustration 16	g00855826
Retainer and Exciter Armature (15) Exciter Armature (16) Retainer (17) Bolts

5. A retainer (16) is used to fasten the exciter armature (15) to the generator. Carefully pass the generator leads through the retainer's opening.

6. Use four bolts (17) to fasten the retainer to the generator.

   Note: When the exciter armature (15) is installed, the bolts (15) must be properly tightened.

   Apply 9S-3263 Thread Lock to bolts (17) before the bolts are installed. Refer to Table 1 for information regarding bolt torque.

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   Table 1

   BOLT TORQUE
   Bolt Size	Torque
   5/16 inch	35.4 N·m (26.11 lb ft)
   3/8 inch	55.8 N·m (41.16 lb ft)

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Illustration 17	g00855822
Shroud and Exciter Field (12) Shroud (13) Exciter Field (14) Bolts

7. Use four bolts (14) to attach shroud (12) (if equipped) and exciter field (13) to the generator.

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Illustration 18	g00855821
Generator With Outboard PM Pilot Exciter (9) Bolts (10) Rotating Pilot Exciter Field (11) Stationary Pilot Exciter Armature

8. On generators with an outboard PM pilot exciter, perform the following procedure:

   1. Place stationary pilot exciter armature (11) and rotating pilot exciter field (10) on the generator.

   2. Use four bolts to attach stationary pilot exciter armature (11) and rotating pilot exciter field (10) to the generator.

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Illustration 19	g00855818
Generator With Outboard PM Pilot Exciter (6) Bolts (7) Mounting Assembly (8) Retainer

9. On generators with an outboard PM pilot exciter, perform the following procedure:

   1. Slide mounting assembly (7) and retainer (8) over the rotor shaft.

   2. Use four bolts to attach mounting assembly (7) and retainer (8) to the rotor shaft.

10. Various rectifier blocks and mounting hardware are used. The rectifier blocks and mounting plates must be installed after the exciter is attached.

End By:

1. Connect the two generator leads to the rectifier blocks.
2. Connect the three exciter leads to the rectifier blocks.
3. For permanent magnet pilot excited generators, connect wires 26, 28, and 30 to the first termination point or the voltage regulator.
4. Connect exciter wires ( F1 and F2) to the first termination point or the voltage regulator.
5. Install the side and rear access panels to the generator.