Operation Of The Line Connection Components Via An Isolating Transformer - Siemens SINAMICS S120 Equipment Manual

Line Connection Booksize
2.2 Line connection variations
2.2.4

Operation of the line connection components via an isolating transformer

The isolating transformer converts the network configuration of the system (e.g. IT/TT
system) to a TN system. Additional voltage adaptation to the permissible voltage tolerance
range is possible.
An isolating transformer must be used in the following cases:
• The line voltage is higher than 480 V 3AC + 10%. The voltage must be reduced to a
• The motors are not approved for use in IT/TT systems.
• A residual-current circuit-breaker is required.
• The installation altitude is higher than 2000 m.
• A line filter is envisaged in an IT/TT system.
Figure 2-5
2-6
permissible line connection voltage via an isolating transformer with a suitable
transformation ratio.
L1
L2
L3
PE
Fuses
Isolating
transformer
Fuses
Line
contactor
Line filter
(optional)
Line reactor
Line module
Isolating transformer
N
U1 V1 W1
DCP DCN
Equipment Manual, (GH2), 04.2004 Edition, 6SL3097-2AC00-0BP0
Further
loads
netz_trenntrafo.vsd
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