ZIEHL-ABEGG DControl PKDT Series - Minimum Airflow Rate (Shutdown Active;Inactive); Reversed Control Function (Act>Set = n+)

Operating instructions Dcontrol Date 0730
TBL02_54-GB 0730 Part-No. 00153238-GB
Page 21 / 28
7.2.7 Minimum airflow rate (Minimum air shutdown active / not active)
The minimum airflow rate can be switched "ON" or "OFF" using dipswitch.
Dipswitch S1-2 OFF: Shutdown active = Without minimum airflow rate
Dipswitch S1-2 ON: Shutdown not active = With minimum airflow rate (factory setting)
When the setpoint is reached, the modulation is reduced to “0“ %, or to the set value if “Min. Speed“ is specified.
♦ If minimum air shutdown is active, when actual value = setpoint, “n-min“ is disconnected to “0“.
♦ When minimum air shutdown is inactive (factory setting) there is no disconnection, i.e. minimum ventilation is
always assured (fan does not go below “n-min“).
7.2.8 Reversed control function (Act>Set = n+)
There are T W O functions for the control´s action, switchover to the heating function is possible by means of the
internal dipswitch, the controller setting made at the factory is for the cooling function.
1. S1-1 OFF ^ increasing output voltage for increasing actual value (cooling)
2. S1-1 ON ^ increasing output voltage for decreasing actual value (heating)
Only for PKDM
Alternatively the change-over of the control function can be made by a contact at digital input D2 "Digital IN 2"!
When terminals “D2”-“D2” are bridged, the device works with the opposite function than the set with dipswitch 1 () 6
general settings).
actual value
30
°
C
Idealised schematic diagram
set value
20
°
C
heatin
g
function e.
g
. for warm-air heaters coolin
g
function e.
g
. for buildin
g
ventilation
U Motor
OFF
Act<Set =n+
Pband
100 %
Pband
ON
Act<Set =n+
Example for temperature control
actual value
10
°
C
U Motor
min s
p
eed
Hysteresis (ON / OFF) approx.
2.5 % off 100 % set value
100 %
actual value
n-min =
35
%
n-m
a
x = 1
00
%
set value
Idealised schematic diagram
Control range