ABB ACS 800 Series, Firmware Manual

Page: 311 / 340

Adaptive Programming examples for crane control
311
Slack rope torque detection
Using Adaptive Programming (AP), you can create a function for detecting slackness
of the ropes on the drum. The slack rope detection is done by monitoring the actual
motor torque and comparing it with a slack-rope-detection torque level. When the
actual torque of the motor falls below the defined level and the slack rope detection
delay has passed, the drive trips on "SLACK FLT".
The function starts to monitor the motor actual torque:
• after the drive has started running,
• the motor has magnetised and
• the speed reference ramp has exceeded 1% of the maximum/minimum speed
limit.
Create an AP file for slack rope torque detection according to the following example.
In the example:
• Par. 84.06 defines the Slack-rope-detection bit input that is used to activate the
Slack rope detection function. The Slack-rope-detection bit is, by default, set to
digital input DI6 (Actual signal 01.17 bit 5).
• Parameter settings:
• User par. 85.01 defines the lack-rope-detection torque level as % of the motor
nominal torque. When the actual motor torque is lower than the value defined in
this parameter, a slack rope is detected. If this condition lasts for a period longer
than the time defined in par 85.02 SLACK ROPE DETECTION DELAY, the drive
trips on "SLACK FLT".
• User par. 85.01 has a scaling of 100. For example, if a torque level of 50% has to
be set, the value entered in this parameter must be 5000. The default for Slack-
rope-detection torque level is set to 50% (par. 85.01 = 50000).
• Par. 85.02 defines the delay time in milliseconds. The default for Slack-rope-
detection delay is set to 2000 ms.
Bit value Description
1 Slack rope detection function is enabled.
0 Slack rope detection function is disabled.