Firmware V1.41 V1
08.11.2022
73/219
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Speed control
Parallel combined control
Stages combined control
The following applies for the calculation:
U
Soll
= speed controller setpoint (0..10 V)
P
Anteil
= proportional component of the controller
I
Anteil
= integral component of the controller
Offset= offset for fan speed input signal (parameter Offset, see menu 3-2-2-1)
The controller reacts directly to control errors with the P-component.
The I-component prevents permanent control errors.
If very small I-components are required, the calculation interval can be extended (default = 1 sec.) using the
Interval i
parameter. The I-component is updated every
Interval
seconds.
I
Wert
= configurable integral factor of the PI controller (parameter
i-factor
, see menu 3-2-2-1)
Interval i= time interval for the calculation of the I
Anteil
(parameter
Interval i
, see menu 3-2-2-1)
Using the parameter
Min. Drehzahl
, the minimum speed of the fan speed controller can be specified. The value
is entered in percent and refers to the 0..10 V analogue output of the controller.
In the event of exceeding a configurable tg-Max threshold (parameter
t
G
-Max / t
G
-Max.HRC.
menu 3-2-2-1), it is
assumed that there is a problem at the speed controller for the fan motors. Power supply bridging is then
activated. The speed controller for the fans is then disabled and the fans are operated directly from the mains
power supply. Switching from controlled operation to power supply bridging and back again is different for each
of the various continuous control modes (speed control, parallel combined control and stages combined
control). See also the following chapter.
In normal closed loop control (HRC not active) the setpoint
tg-Max
is used for switching to mains power
operation. In HRC mode, the parameter
tg-Max.HRC
is used for this. If HRC mode is active, switching to mains
power operation only takes place when the limit value
tg-Max.HRC
is exceeded.
If mains power operation is already active when switching to HRC mode or closed loop control, it remains active
until the actual value has again fallen below the then applicable setpoint (closed loop control or HRC mode).
After the specified setpoint has been reached, the controller switches back to closed loop operation. The power
supply bridging function can be deactivated by setting the parameter
t
G
-Max
to "—".
The parameters for the PI controller, the minimum speed and power supply bridging are only displayed if speed
control, parallel combined control or stages combined control have been set as type of control.
5.6.11 Protection of the Fan Motors / Fan Motors Base Load Rotation
Additional functions for the protection of the fan motors are implemented for the controller. In months with low
outdoor temperature when only a small part of the condenser fans is needed, it can happen that fans seize up
after long standstill time.
A long lasting standstill time can be prevented using the parameter
BaseLoadRot.F
(menu 3-7) to prevent this
seizure. If base load rotation is activated, the following additional entries are displayed on the operating screen:
1.
On time cond.
You can select between 2 operating modes:
Fan protection
If the parameter
On time cond.
is set to
N
, the switching scheme of the fans is left unchanged. Fans switch
sequentially from L1..Ln to and back from Ln..L1. The fans here that were switched off for longer than a
configurable time
Cycle time F.
(menu 3-7) are then activated again for the duration of 20 seconds.
Runtime equalisation
If the value is set to
Y
, the switching sequence for the fans is changed. The fans here are no longer loaded