2 Engineering
2.11 Three-phase motor
DC1 Variable Frequency Drive 04/16 MN04020003Z-EN www.eaton.com 55
2.11.2 Circuit types with three-phase motors
A three-phase motor’s stator winding can be connected in a star connection 
or delta circuit as per the mains voltage (U
LN
 = output voltage U
2
) and the 
rated operational data on the motor’s nameplate (rating plate).
Figure 20: Example of a motor rating plate
Figure 21: Configuration types:
Star-connected circuit (left), Delta circuit (right)
Examples based on figures 20 and 21
Motor in star connection,
mains voltage: three-phase 400 V; output voltage: three-phase 400 V
 DC1-342D2…
Motor in delta circuit,
mains voltage: single-phase 230 V; output voltage: three-phase 230 V
 DC1-124D3…
Motor connection
DC1 variable 
frequency drive
according to
IEC
according to
UL
U U1 (-U2) T1 (-T4)
V
V1 (-V2) T2 (-T5)
CO
W1 (-W2) T3 (-T6)