Constant Speeds/Frequencies; Critical Speeds/Frequencies; Frequency Reference Selection; Frequency Reference Modification - ABB ACS280 Firmware Manual

38 Program features
Settings and diagnostics
• Speed reference ramping - Parameters
23.33 Shape time 2
• Torque reference ramping - Parameters
Torque ramp up time
• Frequency reference ramping - Parameters
Frequency scaling
• Jogging - Parameters
• Motor potentiometer - Parameter
• Emergency stop ("Off3" mode) - Parameter
Events: -

Constant speeds/frequencies


Constant speeds and frequencies are predefined references that can be quickly
activated, for example, through digital inputs. It is possible to define up to 7
speeds for speed control and 7 constant frequencies for frequency control.
WARNING! Speeds and frequencies override the normal reference
irrespective of where the reference is coming from.
Settings and diagnostics
Parameter groups
chain
.
Events: -


Critical speeds/frequencies

Critical speeds (sometimes called "skip speeds") can be predefined for
applications where it is necessary to avoid certain motor speeds or speed
ranges because of, for example, mechanical resonance problems.
The critical speeds function prevents the reference from dwelling within a
critical band for extended times. When a changing reference enters a critical
range, the output of the function freezes until the reference exits the range. Any
instant change in the output is smoothed out by the ramping function further in
the reference chain.
When the drive is limiting the allowed output speeds/frequencies, it limits to
the absolutely lowest critical speed (critical speed low or critical frequency low)
when accelerating from standstill, unless the speed reference is over the upper
critical speed/ frequency limit.
46.01 Speed scaling
and
26.19 Torque ramp down time
and
.
23.20 Acc time jogging
22 Speed reference selection
23.11 23.15
... ,
.
01.30 Nominal torque scale
28.71 28.75
...
23.21 Dec time jogging
and
22.75 Motor potentiometer ramp time
23.23 Emergency stop time
28 Frequency reference
and
23.32 Shape time 1
26.18
,
.
46.02
and
,
.
.
.