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Siemens AG
Entry type: Product note Entry ID: 50596944, Entry date: 06/15/2011

Configuring information for motors for operation on TN, TT, IT supply systems

  • Entry
  • Associated product(s)
1FE, 1FT, 1FK, 1FN, 1FW, 1PH, 1PM motors in conjunction with the SINUMERIK control system and the SINAMICS S120 drive system can be generally operated on TN and TT supply systems with a grounded neutral and IT supply systems.

For operation on IT supply systems, a monitoring device must signal the first fault that occurs between an active part and ground. According to IEC 60364-41, it is recommended that the first fault is removed as quickly as possible.

For line supplies with grounded phase conductor, an isolating transformer with grounded neutral point (secondary) should be connected between the line supply and drive system, in order to prevent the motor insulation from being inadmissibly stressed. TT supply systems generally have a grounded phase conductor, so that in this case an isolating transformer must be used.