Creep Speed - Siemens SIRIUS 3RW55 Manual

7.6

Creep speed

Operating principle
The creep speed function enables the motor to be controlled at low speed in both directions
during operation. The result of this function, however, is that only a reduced torque can be
generated in the motor. Due to possible heat rise of the motor, this function is not suitable for
continuous operation and the use of a measuring sensor (thermoclick or PTC thermistors
type A) is advisable. Furthermore, the creep speed causes mechanical vibrations, which can
reduce the lifetime of the bearings. The creep speed function is active for as long as the
"Creep speed" control command is set.
Application
● In applications with a low counter-torque, e.g. positioning of machine tools.
Parameters
Parameters
Creep speed factor
Creep speed torque
SIRIUS 3RW55 soft starter
Manual, 08/2018, A5E35630887002A/RS-AB/002
Description
Counter-clockwise rotation / Clockwise rotation
The speed is reduced by the creep speed factor, in other words the
rotational speed in creep mode is the quotient derived from rated speed
and creep speed factor.
The creep speed function operates ideally at a creep speed factor of
7 ... 9.
Factory setting: 7
•
Setting range: 3 ... 21
•
Increment: 1
•
Counter-clockwise rotation / Clockwise rotation
The torque generated in the motor is influenced with the creep speed
torque. The maximum torque that can be generated depends on the
selected creep speed. 100 % creep speed torque corresponds to
approximately 30 % of the rated motor torque.
Factory setting: 50%
•
Setting range: 20 ... 100%
•
Increment: 5%
•
Functions
7.6 Creep speed
115