[132]
lb/h
[140]
ft/s
[141]
ft/min
[145]
ft
[160]
°F
[170]
psi
[171]
lb/in
2
[172]
in WG
[173]
ft WG
[174]
in Hg
[180]
HP
This parameter determines the unit that is used for the setpoint reference and feedback that the
PID controller will use for controlling the output frequency of the adjustable frequency drive.
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*).
20-81 PID Normal/Inverse Control
Option:
Function:
[0] *
Normal
[1]
Inverse
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.
Inverse
[1] causes the adjustable frequency drive’s output frequency to increase when the feedback
is greater than the setpoint reference.
20-82 PID Start Speed [RPM]
Range:
Function:
Application
dependent*
[Application dependant]
When the adjustable frequency drive is first started, it initially ramps up to this output speed in
open-loop mode, following the active ramp-up time. When the output speed programmed here is
reached, the adjustable frequency drive will automatically switch to closed-loop mode and the PID
controller will begin to function. This is useful in applications in which the driven load must first
quickly accelerate to a minimum speed when it is started.
NOTE!
This parameter will only be visible if par. 0-02
Motor Speed Unit
is set to [0], RPM.
VLT AQUA Low Harmonic Drive Instruction
Manual
6 How to Program the Low Harmonic Drive
MG.20.T1.22 - VLT
®
is a registered Danfoss trademark
6-33
6