PID Closed Loop menu for VTZ Compressor Drive
Parameter Nº
Par. Description
Default
For PID, change to
Comment
01-00
Configuration Mode
Speed Open
Loop
Process
Allows the drive to receive a feedback from the refri-
geration system, typically pressure or temperature.
In the following it is assumed pressure feedback is
used.Hence, the input frequency to the compressor
can be adjusted according to de cooling demand.
03-01
Reference / Feedback Unit
rpm
Bar or psi
The feedback (suction pressure) can be displayed on
the LCP in its appropriate unit.
03-02
Min. Reference
2100 rpm
-1 [Bar] (-100 if SLC is used)
Sets the minimum range for the pressure transmitter
03-03
Max. Reference
5400 rpm
12 [Bar] (100 if SLC is used)
Sets the maximum range for the pressure transmit-
ter
03-10
Preset reference
0
Not necessary to change
Value will be added to the speed reference or to the
set point for the PID control (closed loop)
03-13
Reference site
linked to Hand
(local) / Auto
(remote)
Select Local or Remote
From where the operator will control the Frequency
Converter. To use a local reference adjusted locally
on the Drive select «local». To apply an external refe-
rence select «Remote». To use SLC it is always nee-
ded to push «Auto On»
03-15
Reference resource 1
Input 53
Leave as Input 53 or set to
«No function»
If PID set point is modified via external reference:
Leave as Input 53. If set point is fixed and set locally
in Drive: Set to «No function»
06-10
Terminal 53 Low Voltage
0
No change
Minimum value in Volts for the reference signal. Only
relevant if external reference is used (input 53 selec-
ted in 3-15)
06-11
Terminal 53 High Voltage
10
No change
Maximum value in Volts for the reference signal.
Only relevant if external reference is used (input 53
selected in 3-15)
06-14
Terminal 53 Low Reference /
Feedb. value
2100
E.g. 1 [Bar]
Only relevant if external reference is used (input 53
selected in 3-15)
06-15
Terminal 53 High ref / Feed. value 5400
E.g. 5 [Bar]
Only relevant if external reference is used (input 53
selected in 3-15
06-20
Terminal 54 Low Voltage
1V
Minimum value in V for the
pressure transmitter’s range
Depends on output from the feedback device. Nor-
mally no changes are needed
06-21
Terminal 54 High Voltage
5V
Maximum value in V for the
pressure transmitter’s range
Depends on output from the feedback device. Nor-
mally no changes are needed
06-22
Terminal 54 Low Current (only
visible if switch set to I)
4
Minimum value in mA for
the pressure transmitter’s
range
Depends on output from the feedback device. Nor-
mally no changes are needed
06-23
Terminal 54 High Current (only
visible if switch set to I)
20
Maximum value in mA for
the pressure transmitter’s
range
Depends on output from the feedback device. Nor-
mally no changes are needed
06-24
Terminal 54 Low ref / Feedb. value -1
Value according to transmit-
ter
Min value for range in Bar of pressure transmitter
06-25
Terminal 54 High ref / Feedb.
value
9
Value according to transmit-
ter
Min value for range in Bar of pressure transmitter
07-20
Process CL Feedback Input
resource
Analog Input 54 If input 54 is used for trans-
mitter no change is needed
Selects which input signal is used for PID-Closed
loop control
07-33
Process PID Gain
2
According to system
Proportional gain of PID. Default values suitable for
most systems for suction pressure control
07-34
Process PID Integration time (ms)
9000 ms
According to system
Integral time of PID in ms. Default valus suitable for
most systems for suction pressure control
SLC
Pres Anti-short cycling
function
Optional
feature
Only active if 13-00 set to On
13-00
Smart Logic Controller On/Off
Off
Set only to On if pressostat fu anti short
cycling are to be active
13-12.0
Comparator 0 (=cut-in pressure
value)
3 Bar
Set desired start pressure
Pressostat function
13-12.1
Comparator 1 (=cut-out pressure
value)
1 Bar
Set desired stop pressure
Pressostat function
13-20.0
Timer 0 (Start-to-Start timer)
5 min
Set desired time from start
to start
Anti-short cycling function, 5 min = 12 starts per
hour allowed
13-20.1
Timer 1 (Minimum Run-time)
0 min
Set desired minimum run-
ning time
Compressor will run for 1 min. before stopping
* SLC: Smart Logic Controller
Instructions
AN000086420674en-000201 | 23
© Danfoss | DCS (CC) | 2019.04
