Danfoss VLT User Manual

20-21 Setpoint 1
Range: Function:
0.000 Proc-
essCtrlU-
nit*
[-999999.999 - 999999.999 Proc-
essCtrlUnit]
Setpoint 1 is used in closed-loop mode to enter a setpoint reference that is used by the adjustable
frequency drive’s PID controller. See the description of par.20-20
Feedback Function .
NOTE!
Setpoint reference entered here is added to any other references that are enabled
(see par. group 3-1*).
20-22 Setpoint 2
Range: Function:
0.000 Proc-
essCtrlU-
nit*
[-999999.999 - 999999.999 Proc-
essCtrlUnit]
Setpoint 2 is used in closed-loop mode to enter a setpoint reference that may be used by the ad-
justable frequency drive’s PID controller. See the description of
Feedback Function , par.
20-20
Feedback Function .
NOTE!
The setpoint reference entered here is added to any
other references that are enabled (see par. group
3-1*).
20-81 PID Normal/ Inverse Control
Option: Function:
[0] * Normal Normal [0] causes the adjustable frequency drive’s output frequency to decrease when the feedback
is greater than the setpoint reference. This is common for pressure-controlled supply fan and pump
applications.
[1] Inverse
Inverse [1] causes the adjustable frequency drive’s output frequency to increase when the feedback
is greater than the setpoint reference. This is common for temperature-controlled cooling applica-
tions, such as cooling towers.
20-93 PID Proportional Gain
Range: Function:
0.50 N/A* [0.00 - 10.00 N/A]
If (Error x Gain) jumps with a value equal to what is set in par. 20-14
Maximum Reference/Feedb. , the PID controller will try to change the output speed
equal to what is set in par.4-13
Motor Speed High Limit [RPM] /par.4-14 Motor Speed High Limit [Hz] but in practice of course limited by this setting.
The proportional band (error causing output to change from 0%–100%) can be calculated by means of the formula:
(
1
Proportional Gain
)
×
(
Max Reference
)
NOTE!
Always set the desired for par. 20-14
Maximum Reference/Feedb. before setting the values for the PID controller in par. group 20-9*.
6 How to program the adjustable frequency
drive
VLT
®
HVAC Drive Instruction Manual
6-48 MG.11.A9.22 - VLT
®
is a registered Danfoss trademark
6

Danfoss VLT Specifications

General

Frequency	50/60 Hz
Enclosure	IP20, IP21, IP55, IP66
Series	VLT
Control Technique	Flux Vector Control
Output Voltage	0-Vinput
Control Method	Fieldbus
Communication Interface	PROFIBUS, CANopen
Protection Features	Overload, Overvoltage, Undervoltage, Short Circuit, Ground Fault
Cooling Method	Liquid Cooled
Storage Temperature	-25°C to +70°C
Relative Humidity	5-95% non-condensing
Altitude	Up to 1000m (3280ft) without derating, up to 4000m (13120ft) with derating
Operating Temperature	-10°C to +50°C (14°F to 122°F)