Slip Detection - ABB ACS880 Firmware Manual

Slip detection

To protect a torque limiter (for example, a slip clutch), it is possible to automatically
apply a reduced (or zero) speed reference whenever slippage is detected. Slip
detection can be based on the difference of chain speed on either side of the torque
limiter, or an external slip-detection switch.
Note: This function works only in the winch mode (EXT2).
Encoder
FEN-xx
When parameter 78.04 Slip detection mode
on the comparison of drive speed, drive torque and chain speed (measured by an
encoder) with the supervision limits. The new reference (protection speed) is applied
after a predefined delay (parameter
In practice, the protection speed is often set to zero if the clutch cannot re-engage
until the motor is stopped.
After the function is activated, the protection speed is active until the user reference
signal reverts to zero.
When parameter 78.04 Slip detection mode
detection, slip detection is based on an external slip-detection switch connected, for
example, to a digital input. The state of the input is read through the pointer
parameter. When the source of the pointer switches On, the drive waits for the slip
delay time to elapse, and then applies the protection speed.
Settings and diagnostics
Parameter group 78 Slip detection
Events: -
DI
Drive
is set to Internal, slip detection is based
78.09 Activation delay
is set to parameter
on page 501.
Winch program features 75
Torque limiter with
slip-detection switch
Motor
time).
78.11 Slip external