Siemens SINAMICS S110 Manual page 62

Mains connection and line-side power components
3.9 Line connection variants
Danger to life due to electric shock if isolating transformer is omitted
To implement safe electrical separation, an isolating transformer must be used with high
voltages. Otherwise, there is a danger to life.
• Install an isolating transformer for voltages of > 3-phase 480 V AC +10% or 240 V AC
Note
Line connection of motors
In combination with the drive system, the motors are generally approved for operation in TN
and TT systems with grounded neutral point and in IT systems.
In use in 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
to protect the motor insulation from continuous excessive stress.
62
WARNING
+10%.
SINAMICS S110
Manual, 07/2015, 6SL3097-4AC10-0BP5