Encoder Adjustment In Operation - Siemens SINAMICS S120 Function Manual

Vector control
4.18 Instructions for commissioning permanent-magnet synchronous motors
4.18.1

Encoder adjustment in operation

This function can only be used for permanent-magnet synchronous motors operating in the
"vector control" mode. You can use this function to readjust encoders that have been
replaced in operation. The encoders can be adjusted within a motor line-up. The adjustment
is also possible when coupled to the load.
Adjusting a new encoder
1. After mounting the encoder, set p1990 = 3 to select a new adjustment.
2. Enable the pulses.
3. In this case, specify a setpoint.
The encoder module checks the consistency of the encoder pulses and zero mark. With this
procedure, you can achieve an accuracy of approx. ±15° electrical. This accuracy is
sufficient for starting with maximum 95% rated torque. A fine calibration/adjustment is
required for higher starting torques.
If, after two motor revolutions, a zero mark has not been detected, the drive switches off with
fault F07970.
Fine adjustment
1. The fine adjustment is started when the motor rotates with p1905 = 90.
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The encoder adjustment is automatically selected when switching on the next time.
The pole position identification determines the offset.
If the zero mark position of the encoder is not known you are prompted to specify a
setpoint to start the drive.
The drive then starts with the specified setpoint.
The zero mark position of the encoder is determined.
The pulse inhibit is set.
The commutation angle offset is determined from the offset and position of the zero mark.
The commutation angle offset is written automatically to parameter p0431.
p1990 = 0 is set automatically at the end of the adjustment and the result saved to the
RAM.
The measurement takes approx.1 minute. The actual steps of the fine encoder
adjustment are displayed using alarm A07976. During the measurement, the difference
between the encoder and the EMF model is determined. The fine adjustment can also be
carried out in no-load operation (idle operation).
Function Manual, (FH1), 01/2013, 6SL3097-4AB00-0BP3
Drive functions