SIRIUS 3RT2 contactors/contactor assemblies 
  2.4 Configuration 
SIRIUS Innovations 
System Manual, 01/2011, A8E56203870002-03 
139 
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1  Rotating field 
2  Rotor's overtravel during the current-free phase 
Figure 2-14  Phasor diagram for motor phase connections made according to the previous diagram 
results in a high switchover current peak 
Changing the direction of rotation from clockwise to counterclockwise  
 
NOTICE 
 
In order to set the motor to counterclockwise rotation, it is not simply a case of swapping 
over two phases at any location. This would result in the same conditions as those 
described for clockwise rotation.  
 
The wiring must be performed as follows in order to keep the switchover current peak which 
occurs on switching from star (wye) to delta as low as possible here too: 
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Figure 2-15  Correct connection of motor phases for counterclockwise motor rotation 
Table 2- 15  Device sizing during normal starting 
Star contactor  Line and delta contactor  Overload relay 
I
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 motor x 0.33  I
e
 motor x 0.58  I
e
 motor x 0.58 
 
 
 
 
Note 
If two phases are swapped over in the network in order to change the direction of rotation, 
the circuit is automatically changed/reversed from the most favorable to the least favorable.