Functions
WE
Configuration
Operating action Y1
OFF
Fb21
Parameters
WE
Range of values
K
P
Heating coil
0.5
0.1 to 99.9
T
N
Heating coil
60 sec 1 to 999 sec
T
V
Heating coil
– – –
– – – to 999 sec
5.4.2 Mixed air chamber
Mixed air chamber in sequential operation
The mixed air chamber is controlled from the Y2 output which can be adapted to the dynam-
ics of the mixed air chamber by means of the parameters
K
p
Mixed air chamber, T
N
Mixed
air chamber and T
v
Mixed air chamber. The parameter Minimum outdoor air rate guaran-
tees an minimum proportion of outdoor air. The operating action of the control output Y2
can be reversed. The default setting is an outdoor air rate of 0 to 100 % which corresponds
to a control signal of 0 to 10 V. By activating Fb22, the operating action is reversed: the out-
door air rate 0 to 100 % then corresponds to 10 to 0 V. On feedforwarding the outdoor
temperature, the
summer time operation
function is taken into account (–> section 6.10.3).
By additionally feedforwarding the exhaust air temperature, the
automatic reversal of the
operating action
takes effect.
If the operating action of the control output Y2 is automatically reversed due to changing
temperatures, while the control is in the sequence range Y1 or Y3, the mixed air chamber is
then reversed with a constant changing rate of 15 % per minute. If there is a considerable
difference in temperature between exhaust air and extract air due to the heat given off by
the fan, the extract air temperature can also be selected as the measured variable in place of
the exhaust air temperature.
Note:
The proportion of outdoor air can be suppressed during the warm-up phase with Fb43 = ON.
Functions
WE
Configuration
Sensor F7, mixed air or extract air
temperature
Fb7 = ON,
option:
SEQ (with extract air sensor)
Fb7 = OFF,
option
:
SEQ (without extract air sensor)
Operating action Y2
OFF
Fb22
Circ. air mode after system start-up
OFF
Fb43 (not with supply air control)
EB 5477 EN
45
Control methods and system components