ABB ACS850 series, Firmware Manual

Page: 50 / 260

50 Program features
Settings
Parameter group 36 Timed functions (page 162 ).
User load curve
The drive output can be limited by defining a user load curve. In practice, the user
load curve consists of an overload and an underload curve, even though neither is
compulsory. Each curve is formed by five points that represent output current or
torque as a function of frequency.
An alarm or fault can be set up to occur when the curve is exceeded. The upper
boundary (overload curve) can also be used as a torque or current limiter.
Settings
Parameter group 34 User load curve (page 154 ).
User U/f curve
The user can define a custom U/f curve (output voltage as a function of frequency).
The curve can be used in special applications where linear and quadratic U/f ratios
are not adequate (e.g. when motor break-away torque needs to be boosted).
Note: Each user-defined point defined must have a higher frequency and higher
voltage than the previous point.
WARNING! High voltage at low frequencies may result in poor performance
or motor damage due to overheating.
Settings
Parameter group 38 Flux ref (page 167 ).