
40 SEBU8219-01
Product Information Section
Product Identification Information
Parallel to Utility
When a Wye conne
cted generator is going to operate
in parallel with a utility system (infinite bus) and
when the secondary of the step-down transformer
in the utility
system is also a Wye connection, the
following may happen. The grounding of both Wye
neutrals may result in circulating currents through
the neutrals
. Also, the coordination of ground fault
protection requires an entire system study. This study
should be done by a certified, registered consultant
who is famili
ar with generator systems. The study will
determine which grounding method should be used.
i01553204
Voltage Connectio ns
SMCS Code: 4450
Three-Phase Voltage Connections
The Wye 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 with grounded neutral is being
used, a two-thirds winding pitch is recommended. If
the generator winding pitch is not two-thirds, third
harmonics will cause a high neutral current. This
current can damage the wiring, which may cause
a fire hazard. A floating neutral does not require a
two-thirds pitch winding.
Wye Configurati
on Diagrams
6 Lead Generators
g00626053
Illustration 39
Typical Wye Configuration (60 Hz, 6 Lead)
12 Lead Generators
g00637319
Illustration 40
Typical Series Wye Configuration (60 Hz, 12 Lead)
This is a typical high voltage connection.