User Load Curve - ABB ACS580 Firmware Manual

98 Program features
The function is also available for scalar motor control with a frequency reference. The
input of the function is shown by
Example
A fan has vibrations in the range of 540...690 rpm and 1380...1560 rpm. To make the
drive avoid these speed ranges,
• the critical speeds function by turning on bit 0 of parameter
function, and
• set the critical speed ranges as in the figure below.
22.01 Speed ref unlimited
(output of function)
1560
1380
690
540
Settings
• Critical speeds: parameters
• Critical frequencies: parameters


User load curve

The User load curve provides a supervisory function that monitors an input signal as
a function of frequency or speed, and load. It shows the status of the monitored signal
and can give a warning or fault based on the violation of a user defined profile.
The user load curve consists of an overload and an underload curve, or just one of
them. Each curve is formed by five points that represent the monitored signal as a
function of frequency or speed.
In the example below, the user load curve is constructed from the motor nominal
torque to which a 10% margin is added and subtracted. The margin curves define a
28.96 Frequency ref act
(rpm)
1 2 3 4
22.51...22.57
28.51...28.57
7.
1 Par. 22.52
2 Par. 22.53
3 Par. 22.54
4 Par. 22.55
22.87 Speed reference act 7
(input of function)
(page 210)
(page 233).
22.51 Critical speed
= 540 rpm
= 690 rpm
= 1380 rpm
= 1560 rpm
(rpm)