Xylem GOULDS Aquavar SPD Serie Instrucciones De Instalación, Operación Y Mantenimiento página 10

Power Supply and Wiring
Section 6
(continued)
Delta/Delta with grounded leg
Another common configuration providing voltage rebalancing with no phase shift between input and output.
Again, depending on the output connections from the drive to motor, the grounded neutral may be a path for
common mode current caused by the drive output.
Ungrounded secondary
Grounding of the transformer secondary is essential to the safety of personnel as well as the safe operation
of the drive. Leaving the secondary floating can permit dangerously high voltages between the chassis of the
drive and the internal power structure components. In many cases this voltage could exceed the rating of the
EMC filter and input MOV protection devices of the drive causing a catastrophic failure. In all cases, the input
power to the drive should be referenced to ground. If the transformer can not be grounded, then an isolation
transformer must be installed with the secondary of the transformer grounded.
Warning
If a power system with an ungrounded secondary is used, the line to ground EMC filter
WARNING
components and line to ground MOV protection must be disconnected or damage to
Hazardous
voltage
the controller can result.
To remove the line to ground EMC filter components, locate the jumper shown below. The jumper is on the left
hand side of the controller on the main board. Move to the disconnected position shown below.
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