V/F Control For Diagnostics - Siemens SINAMICS S120 Function Manual

3.1.9

V/f Control for diagnostics

Description
With V/f control, the motor is operated with an open control loop and does require
speed control or actual current sensing, for example. Operation is possible with a
small amount of motor data.
V/f control can be used to check the following:
S Motor Module
S Power cable between the Motor Module <––> motor
S Motor
S DRIVE-CLiQ cable between the Motor Module <––> motor
S Encoder and actual encoder value
The following motors can be operated with V/f control:
S Induction motors
S Synchronous motors
Caution
V/f control must only be used as a diagnostic function
(e.g. to check that the motor encoder is functioning correctly).
Note
In V/f mode, the calculated actual speed value is always displayed in r0063. The
speed of the encoder (if installed) is displayed in r0061. If an encoder is not
installed, r0061 displays "0".
Note
The operation of synchronous motors with V/f control is allowed only at up to 25 %
of the rated motor speed.
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition
Operating Modes
Servo control
3-91