ENGINE AR-CORE 2543835 - Caterpillar

Three-Phase Voltage Connections
The Wye (Star) Configuration for a 480 V generator and the Delta Configuration for a 240 V generator are given in the following diagrams.The terminals must be connected securely. The terminals must also be insulated with a good quality electrical tape.If a Delta Configuration is used, a two-thirds winding pitch is recommended and is required with 590 frame size generators and above. If the generator winding pitch is not two-thirds, third harmonics will cause a high circulating current. The generator will need to be derated. This current can exceed the winding current rating causing generator overheating and damage which may pose a fire hazard. A Wye (Star) connected generator may require a two-thirds pitch winding if the neutral is solidly grounded. Refer to the Specifications, LEBX6693, "Generator Set Installation Drawings" for more information. A floating neutral does not require a two-thirds pitch winding.Wye (Star) Configuration Diagrams
6 Lead Generators
Illustration 1 g00626053
Typical Wye (Star) Configuration (60 Hz, 6 Lead)
12 Lead Generators
Illustration 2 g00637319
Typical Series Wye (Star) Configuration (60 Hz, 12 Lead)
This is a typical high voltage connection.
Illustration 3 g00637320
Typical Parallel Wye (Star) Configuration (60 Hz, 12 Lead)
This is a typical low voltage connection.
Delta Configuration Diagrams
6 Lead Generators
Illustration 4 g00626129
Typical Delta Configuration (60 Hz, 6 Lead)
12 Lead Generators
Illustration 5 g00626130
Typical Delta Configuration (60 Hz, 12 Lead)
Single-Phase Current From a Three-Phase Generator
Three-phase current and single-phase current can be taken simultaneously from a generator that is connected for three-phase service. In the Wye (Star) Configuration, connect the load to the three-phase leads (any two of the three leads). In the Delta Configuration, connect the load to the three-phase leads (any two of the three leads). In both configurations, this will provide single-phase voltage at the same voltage as three-phase voltage.Connect the load to any phase lead and neutral lead of the Wye (Star) Configuration. This will produce voltage at 58% of three-phase voltage.Refer to Operation Section, "Generator Operation" for allowable single-phase loading unbalance.Single-phase power that is taken from a three-phase source can be a problem. Ensure that the single-phase loading is equally distributed.Do not exceed the nameplate current rating for any one phase.Wye (Star) Configuration Diagrams
6 Lead Generators
Illustration 6 g00626132
Single-Phase Voltage Diagram with 6 Lead Wye (Star) Configuration
12 Lead Generators
Illustration 7 g00637321
Single-Phase Voltage Diagram with 12 Lead Wye (Star) Configuration
Delta Configuration Diagrams
6 Lead Generators
Illustration 8 g00626135
Single-Phase Voltage Diagram with 6 Lead Delta Configuration
12 Lead Generators
Illustration 9 g00626136
Single-Phase Voltage Diagram with 12 Lead Delta Configuration