Ramp 1; Relative Scaling Reference Source - Danfoss VLT FC 51 Series Programming Manual

VLT Micro Drive FC 51
[2]
[11]
[21]

3-18 Relative Scaling Reference Source

Option:
*
[0]
[1]
[2]
[8]
[11]
[21]

4.4.4. 3-4* Ramp 1

A linear ramp is characterized by ramping up at a constant speed until the desired motor speed
has been reached. Some overshoot may be experienced when reaching speed, which may cause
speed jerks for a short while before stabilizing.
An S-ramp accelerates more smoothly thus compensating for jerks when the speed is reached.
See the below figure for a comparison of the two ramp types.
Ramp Times:
Ramp up: Acceleration time. From 0 to nominal motor frequency (par. 1-23).
Ramp down: Deceleration time. From nominal motor frequency (par. 1-23) to 0.
Limitation:
Too short ramp up time can result in Torque limit warning (W12) and/or DC over voltage warning
(W7). Ramping is stopped when the frequency converter has reached Torque limit motor mode
(par. 4-16).
Too short ramp down time can result in Torque limit warning (W12) and/or DC over voltage
warning (W7). Ramping is stopped when the frequency converter reaches the Torque limit gen-
erator mode (par. 4-17) and/or the internal DC over voltage limit.
Analog Input 60 Use signals from analog input 60 as reference.
* Local Bus Ref. Use signals from local bus as reference.
LCP Potentiometer Use signals from LCP potentiometer as reference.
Function:
Select the source for a variable value to be added to the fixed
value defined in par. 3-14,
No Function The function is disabled
Analog Input 53 Select analog input 53 as relative scaling reference source.
Analog Input 54 Select analog input 54 as relative scaling reference source.
Pulse Input 33 Select pulse input 33 as relative scaling reference source.
Local Bus Ref. Select local bus ref. as relative scaling reference source.
LCP Potentiometer Select LCP potentiometer as relative scaling reference source.
MG.02.C2.02 - VLT ® is a registered Danfoss trademark
4. Parameter Descriptions
Preset Relative Reference
.
4
33