ABB DCS880 series - IT (Ungrounded) Systems; Supply Voltage; Connecting the Power Cables

Electrical installation
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3ADW000462R0401 DCS880 Hardware manual e d
IT (ungrounded) systems
Don’t use EMC filters in IT systems.
The screen winding of existing dedicated transformers must be grounded.
For installation 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 supply voltages of:
Auxiliary voltage XAUX (X99) on SDCS-PIN-H01 /
SDCS-POW-H01
Cooling fan Terminals
Mains voltage for field circuit U1, V1, W1 (if used)
Mains voltage for armature circuit U1, V1, W1
Connecting the power cables
Check:
Grounding and screening of power cables see manual Technical guide
.
Cross sectional areas and tightening torques of power cable see chapter
Cross-sectional areas - Tightening torques
.
V
U1
V1
W1
SA_550_003_netzanschl_a.ai
Voltage shift in
case of earth fault
Earth fault