8
05.01
8.10 Star–delta mode
8-298
©
Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
8.10
Star–delta mode
SIMODRIVE 611 supports the use of motors that can changeover between star/
delta configurations.
At lower speeds, the drive is operated in the star circuit configuration (high
torque) and at higher speeds, in the delta circuit configuration (high stall torque).
Changeover is also possible during operation.
The speed when changing–over from a star into a delta configuration (star to
delta operation) must lie within the stall power range for star operation (refer to
the speed–torque diagram for Y/
Δ
operation).
A star–delta changeover is only permitted below the star field–weakening
speed.
n
ratedY
n
rated
D
M
stall Y
M
ratedY
0
M
M
stall
D
M
rated
D
1
n
Y
1
n
D
n
Fig. 8-25
Speed–torque diagram for Y/
Δ
operation of induction motors
Note
If, in the delta mode, a torque lower than M
rated
is taken, an appropriately
smaller power module can be selected (as a maximum up to root 3)!
!
Warning
During the phase when changing–over from Y to
Δ
operation, no torque may be
demanded from the 1PH motor. In this case, a minimum dead time of 0.5 s
must be taken into account for contactor changeover times, safety margins,
de–magnetizing and magnetizing operations.
The star–delta operation of synchronous motors with 611D modules is used to
extend the speed range.
The speed range selection may be changed only in the stopped state.
Application
8 Important Circuit Information
05.08