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Entry type: FAQ Entry ID: 25220071, Entry date: 08/12/2015

MICROMASTER 4 (MM4), SINAMICS G110/ G120: Most standard power supply types (power supply systems).

  • Entry
  • Associated product(s)
This FAQ applies to the SINAMICS G110/G120 and MICROMASTER 4 inverters.

Which power supply systems are available and which systems are permissible for use with inverters?

Most standard power supply types found in the world fall into three categories. These categories
relate to the International standard in IEC 60364. IEC 60364 distinguishes between the three
different earthing arrangements TN, TT and IT.

These codes are determined by the following table:

The first letter indicates the connection between earth and the power-supply equipment
(generator or transformer):

T = Direct connection of a point with earth (taken from French for earth: Terre)
I = No point is connected with earth. This may also be a high impedance connection

The second letter indicates the connection between earth and the electrical device being

T = Direct connection with earth. Independent of any other earth connection in the supply system.
N = Connection to earth via the supply network.

The third and fourth letters signifies the location of the earth conductor:

S = Neutral and earth are separate.
C = Neutral and earth are combined into a single conductor

 For MM4 and G110/G120 the following applies:

  • The drive inverters can be operated on all three line supply systems (TN, TT, IT)
  • Only permanently connected line supply connections are permitted
  • Drive inverters must always be earthed- both through the cable as well as through the frame/ chassis
  • Every drive inverter must be separately fused as the fuses are used in this case cable protection
  • Only type B r.c.c.b's (residual-current circuit breaker) may be used (one r.c.c.b. for each drive inverter)

Further information please find in the attached PDF- file:   pdf_power_supply_types_en_v1.pdf (342,0 KB) 

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