Siemens SINAMICS G120 Operating Instructions Manual page 37

Components for United States / Canadian installations (UL/CSA)
In order that the system is UL/CSA-compliant, use UL/CSA-certified J-type fuses, overload
circuit-breakers or intrinsically safe motor protection devices. For each frame size A to C use
class 1 75° C copper wire only.
Install the converter with any external recommended suppressor with the following features:
● Surge-protective devices; device shall be a Listed Surge-protective device (Category
● Rated nominal voltage 480/277 V
● Clamping voltage V
● Suitable for Type 1 or Type 2 SPD application.
● Clamping shall be provided between phases and also between phase and ground.
Star connection and delta connection
With SIEMENS motors, you will see a
diagram of both connection types on the
inside of the cover of the terminal box:
 Star connection (Y)
 Delta connection (Δ)
The motor rating plate provides information
about the correct connection data.
Examples for operating the inverter and motor on a 400 V line supply
Assumption: The motor rating plate states 230/400 V Δ/Y.
Case 1: A motor is normally operated between standstill and its rated speed (i.e. a speed
corresponding to the line frequency). In this case, you need to connect the motor in Y.
Operating the motor above its rated speed is only possible in field weakening, i.e. the motor
torque available is reduced above the rated speed.
Case 2: If you want to operate the motor with the "87 Hz characteristic", you need to connect
the motor in Δ.
With the 87 Hz characteristic, the motor's power output increases. The 87 Hz characteristic
is mainly used with geared motors.
SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB
code VZCA and VZCA7).
= 2000 V, I
PR
, 50/60 Hz, 3-phase.
AC
= 3 kA min, MCOV = 550 V
N
Installing
4.6 Connecting the converter
, SCCR = 40 kA.
AC
35