ABB ACS880 User Manual page 19

Safely-limited speed without the encoder interface (option +q966) for multidrives

Hide thumbs Also See for ACS880:

Table of Contents

The user or a PLC de-energizes the applicable digital inputs of the FSO module. This

activates the SLS request. The FSO module starts a counter for time (B).

After the safety function response time (A), the inverter unit starts to decelerate the

motor according to the user-defined deceleration ramp. The FSO module starts SLS

monitoring and energizes the digital output that indicates the SLS status when the motor

speed is in the middle of the SLS1 trip limit and the SLS1 limit.

The actual motor speed reaches the SLS1 limit positive. The inverter unit limits the

motor speed reference so that the motor speed stays at or below the SLS1 limit positive.

The FSO module monitors the actual motor speed. If the motor speed goes above the

SLS1 trip limit positive (D), the FSO module activates the SSE function (refer to section

SLS with speed below the monitored speed (page

(3b) Time (B) has elapsed. The FSO module starts SLS monitoring (if not already

started).

Note: If the motor speed is not below the SLS monitoring limit after time B has elapsed,

the FSO module activates the SSE function. Depending on SSE function parameter

settings, the motor either coasts to a stop ("Immediate STO") or ramps down to zero

speed ("Emergency ramp"). For more information, refer to section

SSE function (page 36)

The user or a PLC energizes the applicable digital inputs of the FSO module. This

deactivates the SLS request.

The FSO module acknowledges the SLS function automatically. This is set to be

automatic by an FSO parameter (SLSx.02), and no external acknowledgement input

is used. The FSO module stops SLS monitoring and de-energizes the digital output

that indicates the SLS status. The inverter unit returns to normal operation and starts

to follow its ordinary speed reference. The inverter unit accelerates the motor to the

desired speed along its acceleration ramp (inverter unit parameter).

Normal operation continues.

and the FSO module user's manual.

Option description 19

17)).

Parameters for the

Table of Contents