Methods Of Line Connection - Siemens SINAMICS S120 Equipment Manual

Mains connection and line-side power components
4.8 Line connection variants
NOTICE
Damage of the drive line-up when operating on an IT system without a motor reactor
If the drive unit is operated without a motor reactor in an IT system, a ground fault on the
motor side of the Power Modules can cause damage to the drive line-up or trip the
overcurrent protective equipment.
• We recommend that a motor reactor is used to provide better protection.
4.8.2

Methods of line connection

A distinction is made between the following line connection types:
● Line connection components to be directly connected to the line supply
● Operation of the line connection components via an autotransformer
● Operation of the line connection components via an isolating transformer
Electric shock if an isolating transformer is not used
To implement safe electrical separation, an isolating transformer must be used with high
voltages. Otherwise, there is a danger to life.
• For voltages > 3 AC 690 V, > 3 AC 480 V +10 % or 1 AC 240 V + 10 %, install an
Note
Line connection of motors
In combination with the drive system, the motors are generally approved for operation on TN
and TT systems with grounded neutral point and on IT systems.
In use on IT systems, the occurrence of a first fault between a live part and ground must be
signaled by a monitoring device. The first fault must be removed as quickly as possible to
minimize temporary overload of the motor insulation.
In all other systems, except TN and TT systems with grounded neutral point and IT systems,
such as systems with a grounded line conductor, an isolating transformer with grounded
neutral point (secondary side) must be connected between the supply and the drive system
in order to protect the motor insulation from continuous excessive stress.
70
WARNING
isolating transformer.
Manual, 06/2019, 6SL3097-5AL00-0BP1
AC Drive