Alternator - Delco 27SI Caterpillar


Component Description

Usage:

D6D 01Y



Illustration 1g00901310

27-SI Alternator

(1) Field Winding

(2) Rotor

(3) Stator

(4) Regulator

(5) Rectifier

(6) Capacitor

(7) Diode Assembly

Field Winding




Illustration 2g00901311

Field winding (1) is a stationary coil that provides a magnetic field for the rotor.

Rotor




Illustration 3g00901306

Rotor (2) consists of a magnetic core that is mounted on a shaft. The rotor rotates on the shaft. The rotor is magnetized by the field winding, and the rotor provides a magnetic field for the stator.

The core is divided into two poles that are separated by an insulated ring. When current flows in the field winding, the core is magnetized. One side becomes the "N" pole, and the other side becomes the "S" pole.

When the current in the field winding stops, the core does not lose the magnetism completely. The core still contains some residual magnetism.

Stator




Illustration 4g00901308

Stator (3) consists of a stator core and three independent windings. As the rotor turns, a varying magnetic field causes the stator windings to produce three-phase AC voltage. The stator is supported by the front frame and by the rear frame.

Rectifier




Illustration 5g00901305

Rectifier (5) is a three-phase full wave rectifier. The rectifier changes the AC voltage that is produced by the stator to DC voltage. The rectifier contains positive diodes and negative diodes. The DC voltage from the positive diodes and from the negative diodes is delivered to the battery terminals.

Diode Assembly




Illustration 6g00901304

Diode assembly (7) contains three exciter diodes. The negative diodes from rectifier (5) and the exciter diodes change the AC voltage from the stator to DC voltage. The DC voltage from the exciter diodes and from the negative diodes energizes the field winding.

Capacitor




Illustration 7g00901309

Capacitor (6) performs the following tasks:

  • The capacitor protects the rectifier diodes from high transient voltages.

  • The capacitor protects the diode assembly from high transient voltages.

  • The capacitor smooths the output of the rectifier.

  • The capacitor suppresses radio interference.

  • The capacitor reduces electrical noise.

The capacitor is mounted inside the rear frame. The capacitor is connected to the rectifier.

Regulator




Illustration 8g00901307

Regulator (4) limits the output voltage of the alternator to a preset value by controlling the current through the field winding. The regulator electronically switches the connection between the field coil and ground. The switching occurs at variable rates. The regulator is mounted inside the rear frame. The regulator is totally enclosed. The regulator cannot be adjusted.

Caterpillar Information System:

12H, 140H, 143H, 160H and 163H Motor Graders Hydraulic and Steering System Steering Cylinder
G3520B Engines E868 Gas Flow Control Valve Malfunction
G3520B Engines E867 Improper Gas Flow Control Valve Response
Alternator - Delco 27SI Normal Operation
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Crankshaft
G3520B Engines E242 Engine Overload
G3520B Engines E226 Driven Equipment Not Ready
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Cylinder Block
Alternator - Delco 27SI General Information
G3520B Engines E004 Engine Overspeed Shutdown
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Water Temperature Regulator
C0.5, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Engine Oil Pan
Alternator - Delco 27SI General Information
Alternator - Delco 27SI Service Tools
3524B Engine for Caterpillar Built Machines Alternator - Remove and Install
Alternator - Delco 27SI Alternator
C0.5, C0.7, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Starting the Engine
Alternator - Delco 27SI Alternator - Disassemble
C0.5, C0.7, C0.7, C1.1/3011C, C1.5/3013C, C1.6 and C2.2/3024C/3024CT Industrial Engines and Engines for Caterpillar Built Machines Cold Weather Starting
C-10, C-12 and C-15 On-highway Engines System Overview
Alternator - Delco 27SI Alternator - Assemble
C-10, C-12 and C-15 On-highway Engines Sensors and Electrical Connectors
C-10, C-12 and C-15 On-highway Engines Selected Engine Rating
C11, C13 and C15 On-highway Engines Cruise Control Parameters
Back to top
The names Caterpillar, John Deere, JD, JCB, Hyundai or any other original equipment manufacturers are registered trademarks of the respective original equipment manufacturers. All names, descriptions, numbers and symbols are used for reference purposes only.
CH-Part.com is in no way associated with any of the manufacturers we have listed. All manufacturer's names and descriptions are for reference only.