PIPE-EXTENSION 7E9871 - Caterpillar

Three-Phase Voltage Connections
The Wye Configuration for a 480 V generator and the Delta Configuration 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 with grounded neutral is being 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 neutral current. This current can damage the wiring and cause a fire hazard. A floating neutral does not require a two-thirds pitch winding.Wye Configuration Diagrams
6 Lead Generators
Illustration 1 g00626053
Typical Wye Configuration (60 Hz, 6 Lead)
10 Lead Generators
Illustration 2 g00626051
Typical Series Wye Configuration (60 Hz, 10 Lead) - for 3306B and 3406C generator sets only
This is a typical high voltage connection.
Illustration 3 g00626054
Typical Parallel Wye Configuration (60 Hz, 10 Lead) - for 3306B and 3406C generator sets only
This is a typical low voltage connection.
12 Lead Generators
Illustration 4 g00637319
Typical Series Wye Configuration (60 Hz, 12 Lead) - for 3406E, 3412C and 3500 series generator sets only
This is a typical high voltage connection.
Illustration 5 g00637320
Typical Parallel Wye Configuration (60 Hz, 12 Lead) - for 3406E, 3412C and 3500 series generator sets only
This is a typical high voltage connection.
Delta Configuration Diagrams
6 Lead Generators
Illustration 6 g00626129
Typical Delta Configuration (60 Hz, 6 Lead)
12 Lead Generators
Illustration 7 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 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 Configuration. This will produce voltage at 58% of three-phase voltage.In the Delta Configuration that produces 240 Volts 60 Hz three-phase power, the voltages will be 208 Volts between the high phase and neutral and 240 Volts between either one of the low phases and neutral.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 Configuration Diagrams
6 Lead Generators
Illustration 8 g00626132
Single-Phase Voltage Diagram with 6 Lead Wye Configuration
10 Lead Generators
Illustration 9 g00626133
Single-Phase Voltage Diagram with 10 Lead Wye Configuration (for 3306B and 3406C generator sets only)
12 Lead Generators
Illustration 10 g00637321
Single-Phase Voltage Diagram with 12 Lead Wye Configuration (for 3406E, 3412C and 3500 series generator sets only)
Delta Configuration Diagrams
6 Lead Generators
Illustration 11 g00626135
Single-Phase Voltage Diagram with 6 Lead Delta Configuration
12 Lead Generators
Illustration 12 g00626136
Single-Phase Voltage Diagram with 12 Lead Delta Configuration