ABB DCS550 - Connecting the Power Cables; IT (Ungrounded) Systems; Power Connections; Supply Voltage

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Electrical installation
3ADW000379R0501 DCS550 Manual e e
Power connections
IT (ungrounded) systems
Don’t use EMC filters in IT systems:
The screen winding of an existing dedicated transformers
must be
grounded:
For installations without low voltage switch (e.g. contactor, air-
circuit
-breaker) use an overvoltage protection on the
secondary side of the mains transformer.
The voltage shift of the isolated supply must not be larger than
the voltage
shift in case on an earth fault:
Supply voltage
Check voltage levels of:
− auxiliary voltage (X99 on SDCS-PIN-F),
− cooling fan terminals and
− mains voltage connected to U1, V1, W1.
Connecting the power cables
Check:
− Grounding and screening of power cables see chapter Cabling
.
− Cross sectional areas and tightening torques of power cable, see chapter Cross-sectional areas -
Tightening torques.
Mains filter
V
U1
V1
W1
SA_550_003_netzanschl_a.ai
Voltage shift in
case of earth fault
Earth fault