ABB ACS880-04XT - Page 53

ESP program features 53
The action (none, warning or fault) taken when the signal exits the allowed operation
area can be selected separately for overload and underload conditions (parameters
79.19 and 79.49 respectively). Each condition also has an optional timer to delay the
selected action (79.18 and 79.48).
The diagram below illustrates various underload protection scenarios and possible
responses.
The diagram below illustrates various overload protection scenarios and possible
responses.
Warning + Shutdown
Underload warning
Fault
Load signal / Limit
Reference
Underload delay
Underload act
Underload recovery active
Underload boost active
Underload drop active
Warning
Fault
Shutdown
Delay
time
Delay
time
Delay
time
Load signal / Limit
Reference
Overload delay
Overload act
Warning
Fault
Shutdown
Overload safe speed active
Delay
time
Delay
time
Delay
time
Warning + Shutdown
Overload warning
Fault