VLT
®
6000 HVAC
10
MG.60.G2.02 - VLT is a registered Danfoss Trademark
PID Control Functions (42, 61-65, 68-74)
The VLT 6000 has a sophisticated built-in propor-
tional, integral, derivative (PID) controller. The PID
controller is activated by setting parameter 100,
Configuration
, to
Closed loop
through the drive’s
keypad.
The PID controller in the VLT 6000 supports two
feedback values and two setpoints. The feedback
can be received in the form of network bus signals
and/or standard 0-10 V transmitters. The 2 setpoint
controller is capable of controlling return fans based
on a fixed differential flow, secondary pumping
systems, and so on. This can be used to supple-
ment the BMS system to save on points or ca-
pacity. For details on use of the two feedback/
setpoint feature, refer to the
VLT 6000 Operating
Instructions
. Data points 43 and 44 show the status
of an FLN command to the drive.
The points PI GAIN and PI TIME are gain
parameters similar to the P and I gains in the FLN
TECs. The Danfoss PI loop is structured differently
than the Siemens loop, so there is not a one-to-one
correspondence between the gains. The following
formulas allow translation between Danfoss and
Siemens gains.
Converting from Danfoss PI gains to Siemens P and
I gains:
0.0015
0.0015
0.0015
0.0015
****
TIME
TIME
TIME
TIME
PI
PI
PI
PI
GAIN
GAIN
GAIN
GAIN
PI
PI
PI
PI
GAIN
GAIN
GAIN
GAIN
IIII
0.0015
0.0015
0.0015
0.0015
****
GAIN
GAIN
GAIN
GAIN
PI
PI
PI
PI
GAIN
GAIN
GAIN
GAIN
P
P
P
P
DANFOSS
DANFOSS
DANFOSS
DANFOSS
DANFOSS
DANFOSS
DANFOSS
DANFOSS
SIEMENS
SIEMENS
SIEMENS
SIEMENS
DANFOSS
DANFOSS
DANFOSS
DANFOSS
SIEMENS
SIEMENS
SIEMENS
SIEMENS
=
=
SIEMENS
SIEMENS
SIEMENS
SIEMENS
SIEMENS
SIEMENS
SIEMENS
SIEMENS
DANFOSS
DANFOSS
DANFOSS
DANFOSS
SIEMENS
SIEMENS
SIEMENS
SIEMENS
DANFOSS
DANFOSS
DANFOSS
DANFOSS
GAIN
GAIN
GAIN
GAIN
I
III
GAIN
GAIN
GAIN
GAIN
P
P
P
P
TIME
TIME
TIME
TIME
PI
PI
PI
PI
667
667
667
667
****
GAIN
GAIN
GAIN
GAIN
P
P
P
P
GAIN
GAIN
GAIN
GAIN
PI
PI
PI
PI
=
=
Sleep Mode (54-59)
Sleep mode automatically stops the drive when
demand is low over a period of time. When the
system demand increases, the drive restarts the
motor to reach the desired output. Sleep mode has
great energy savings potential and saves wear and
tear on equipment. Unlike a setback timer, the drive
is always available to run when a preset “wakeup”
demand is reached. See parameters 403 through
406 in the
VLT 6000 Operating Instructions
for more
detail.
Drive Control Display (80-86)
The operational status of the drive is readily available
on the FLN serial interface bus. The drive displays
various states including ready to start, waiting for
run enable, run, fault reset and stop.
Terminals 53, 54, 60 (87-89)
Two analog voltage input terminals 53 and 54 (0 to
10 VDC) and one analog current terminal 60 (0 to
20 mA) are provided for reference or feedback
signals. The applied electrical signal can be read by
data points 87 to 89 in volts and mA. This can be
very useful during commissioning to calibrate
transmitters. This can also be used to convert any
other analog transmitter in the installation into a
digital bus signal, even if the signal is not used by
the drive. In this case, the input terminal should be
programmed to
No Function
so it does not to
influence the drive’s operation.
Faults, Warnings and Alarms (90-94)
The drive displays a warning or tripped by a fault
condition. It also can retrieve the last warning or
fault trip for display. The drive can be reset through
the FLN serial bus to resume normal drive operation.
Error Status (99)
Data point 99 is implemented in the point map but is
not used in this application.
Converting from Siemens P and I gains to
Danfoss PI gains:
