84 Program features
Settings and diagnostics
Parameters common to motor thermal protection and motor overload protection:
…
(page
).
Parameters specific to motor overload protection:
(page
(page
Thermal protection of motor cable
The control program contains a thermal protection function for the motor cable. This
function should be used, for example, when the nominal current of the drive exceeds
the current-carrying capacity of the motor cable.
The program calculates the temperature of the cable on the basis of the following
data:
• Measured output current (parameter
)
• Nominal continuous current rating of the cable, specified by
, and
• Thermal time constant of the cable, specified by
When the calculated temperature of the cable reaches 102% of the rated maximum,
a warning (
) is given. The drive trips on a fault (
) when 106% is reached.
Settings
(page
).
User load curve
The user load curve provides a function that monitors an input signal (eg. motor
torque or motor current) as a function of drive output speed or frequency. The
function includes both high limit (overload) and low limit (underload) monitoring.
Overload monitoring can, for example, be used to detect a pump becoming clogged
or a saw blade hitting a knot. Underload monitoring can detect the load being lost, for
example because of the snapping of a transmission belt.
The monitoring is effective within a motor speed and/or frequency range. The
frequency range is used with a frequency reference in scalar motor control mode;
otherwise, the speed range is used. The range is defined by five speed (parameters
) or frequency (
) values. The values are positive, but the
monitoring is symmetrically active in the negative direction as the sign of the
monitored signal is ignored. Outside the speed/frequency range, the monitoring is
disabled.
An underload (
) and overload (
…
) limit is set for each of the
five speed or frequency points. Between these points, the limits are interpolated
linearly to form overload and underload curves.
Summary of Contents for ACS880-x04
Page 1: ... ABB INDUSTRIAL DRIVES ACS880 primary control program Firmware manual ...
Page 4: ......
Page 18: ...18 Using the control panel ...
Page 24: ...24 Control locations and operating modes ...
Page 112: ...112 Application macros ...
Page 496: ...496 Additional parameter data ...
Page 544: ...544 Fault tracing ...
Page 602: ...602 Control chain diagrams ...