FILTER-ENGINE OIL 3911315 - Caterpillar

Introduction
This Special Instruction provides the necessary information required to convert the following Frame Generators from Self Excited (SE) to Permanent Magent (PM). Reference: Service Manual Module, SENR5359, "SR4B Generator".Reference: Service Manual Module, SENR4794, "Connection Diagrams: SR4 & SR4B Generators, Voltage Regulators, Options".System Components
The following components already exist on the SE generator, and are re-used when converting to PM: Exciter Stator: The exciter stator together with the exciter rotor provides DC current to the main field. The stator is located in the same position on the PM and SE generators covered by this instruction. It is bolted to the outboard edge of the bearing bracket. Exciter Rotor: The exciter rotor together with the exciter stator and rectifier block provides DC current to the main field. The rotor is located in the same position on the rotor shaft for both the PM and SE generators covered by this instruction. Rectifier Block: The one-piece 6-diode bridge rectifier circuit receives three-phase AC from the exciter rotor and converts (rectifies) this power into DC. The DC power is then routed to the main field. The rectifier is bolted to a powder metal washer on the end of the rotor shaft by two screws.The following components are the major parts of the new 142-6021 Conversion Group-Generator kit to convert from SE to PM: Pilot Exciter Stator: The pilot exciter stator together with the pilot exciter rotor provide AC power for the voltage regulator. The regulator rectifies the AC power to DC and a controlled amount is fed to the main exciter. The stator is bolted to the bearing bracket. Pilot Exciter Rotor: The permanent magnet pilot exciter (rotor) together with the pilot exciter stator provide AC power for the voltage regulator. The regulator rectifies the AC power to DC and a controlled amount is fed to the main exciter. The PM rotor is keyed to the rotor shaft and is held in place by a spacer. A new 114-5510 PM Voltage Regulator is also required for this conversion.Procedure for Removing SE Components
Typical Generator Set showing side (1) and rear access panels (2)
Before working inside the generator, make sure that the starter motor can not be activated by any automatic or manual signal.
1. Remove the side and rear access panels from the generator2. Disconnect exciter wires F1 and F2 from their termination point on the voltage regulator. Pull the wires from the harness bundles and place them near the exciter field (stator). Note the location of the F1 and F2 leads on the exciter stator for re-installation.
Diode rectifier block & attached heatsink, showing proper lead-terminal attachments.3. Disconnect the leads from the rectifier bridge, making note of the terminals they are attached to for reference during re-installation.4. Remove the rectifier bridge and attached heatsink by removing the two #10-32 allen screws. Set aside for later re-installation. 5. Remove exciter cover assembly (3) by removing four 5/16 bolts (4). These bolts also attach the exciter stator to the bracket. Set aside for later re-installation.6. The exciter stator