Siemens SINAMICS G220 - Page 450

Parameter p1821 can only be adjusted during commissioning.
NOTICE
Damage to the motor caused by unregulated acceleration
When using an external actual speed value for the speed controller via p1440, positive
feedback can occur in the closed-loop speed control when the direction is reversed, which can
cause the motor to accelerate up to its limit speed and su󹪜er damage as a result.
• When reversing the direction of the motor, also change the polarity of the external actual
speed value.
Description of function
Parameters p1820 and p1821 change the direction of rotation of the motor without the motor
power connections having to be swapped.
Parameter p1820 changes the output phase sequence in the converter. This reverses the
rotating 󹪝eld of the motor. When using an encoderless motor, it is su󹪟cient to change
p1820. When operating a motor with an encoder, the encoder signal must also be inverted,
forexample using p0410.
Parameter p1821 also changes the direction of rotation of the motor, in its case by changing
the output phase sequence of the converter. p1821 inverts the encoder signal like p1820.
The direction reversal can be detected with reference to the motor direction of rotation and
via the phase-to-neutral voltage r0089. The speed setpoint and actual value, the torque
setpoint and actual value and the relative position change remain unchanged. The absolute
position reference is lost on reversal.
Parameters
The following list contains the parameters of the "Direction reversal without changing the
setpoint" function.
Number Name Unit
r0069[0...8] Phase current actual value [A]
r0089[0...2] Actual phase voltage (motor) [V]
p1820[0...n] Reverse the output phase sequence 
p1821[0...n] Direction of rotation 
p1959[0...n].0...14 Rotating measurement con󹪝guration 
Functions
14.9Setpoint channel
SINAMICS G220 converter
448 Operating Instructions, 04/2024, FW V6.2, A5E51781573B AB