Drive System/Coil Selection - Siemens SIRIUS 3RT Series System Manual

Application area
Contactor assemblies
Operation of a motor in
two directions of
rotation
(3RA23 reversing
contactor assembly)
Starting three-phase
motors with reduced
starting current peaks
(3RA24 contactor
assembly for star-delta
(wye-delta) start)
2.4.2

Drive system/Coil selection

The 3RT2 power contactors and 3RH2 contactor relays can be supplied with drives for all
standard AC and DC coil voltages. In addition, 3RT2 power contactors of size S0 are
available with electronic UC drives, which feature an extended operating range (helping to
reduce variance) and have lower closing and holding powers, which enable less power to be
consumed in the control cabinet. The UC drive can be operated with either AC or DC
voltage. This is facilitated by control electronics with an upstream DC drive.
AC and DC drives
Control voltage AC control or DC control
Operating range 0.8 to 1.1 x U
Coil surge Optional (integrated in coupling relays)
suppressor
24 V
Preferred 
voltages
110 V

220/230 V

30 versions for AC control
Reduced variance 
15 versions for DC control

Coil power : AC coil
3)
Switch-on 65 VA
 
Holding 8.5 VA
 
For further details, refer to the chapter titled "Technical data".
1)
At 280 V: high limit = 1.1 x U
2)
Example: contactor (size S0), 7.5 kW, 24 V.
3)
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
Description and suitable contactor versions
Contactor assembly for operation of a three-phase motor in two directions of rotation.
3RA23 reversing contactor assemblies

Contactor assembly for reducing the starting current and starting torque when starting three-
phase motors.
3RA24 contactor assemblies for star-delta (wye-delta) start

S 1)
DC coil
5.9 W

5.9 W

.
S
SIRIUS 3RT2 contactors/contactor assemblies
Electronic drive (UC drive)
UC control
0.7 to 1.3 x U
S
Integrated
21 to 28 V

95 to 130 V

200 to 280 V

3 versions for the entire AC/DC range
AC mode
6.5 VA

1.26 VA

2.4 Configuration
2)
DC mode
6.7 W

0.8 W

117