FCP manual
Code +030220391 – rel 1.2 25/03/08
16
6.5 Cut-off function
When the output of the controller decreases until reaching the minimum value set, the output is forced to zero and remains at this value until the conditions require an
output value that is greater than or equal to the minimum value set.
OUT
CUT-OFF Off
max
min
setp
100%
100%
OUT
CUT-OFF On
max
min
setp
100%
100%
hyst
Fig. 6.b
The change from the minimum output to zero output and vice-versa is performed using an hysteresis, so as to avoid unwanted fluctuations. The hysteresis can be
set by parameter (default 2% of the operating range of the probes)
By default the function is associated with the position of dipswitch 4.
Dipswitch Function
OFF: function disabled (default) Dip4 enable the function selected by par. DIP4 (default Cut-
off)
ON: function enabled
Table 6.a.or
The status of dipswitch 4 has priority over the parameter that enables the associated function.
Associated parameters
par. Spv Modb range def uom description
ECOF D3 3 0/1 0 1 Cut-off function 0=disabled 1=enabled
COFH I12 112 2 to 100 2 1% Cut-off activation hysteresis
DIP4 I20 120 0 to 8 1 1 Function associated with dipswitch 4 0=no function
1=Cut-off
2=Speed-up
3=Output saturation
4=Long impulse phase control
5=Reverse mode
6=Slave mode 1
7=Slave mode 2
8=Slave mode 3
Table 6.a.p
6.6 Output saturation function
If the maximum output set is less than the maximum possible (100% is equivalent to the full mains voltage), when the control output increases until reaching the maximum
value set, the output is forced to the maximum possible and remains there until the conditions require an output value that is less than or equal to the maximum value set.
The change from the maximum output set to maximum output possible and vice-versa is performed using an hysteresis, so as to avoid unwanted fluctuations. The
hysteresis is 2% of the operating range of the probes. By default the function is disabled (alternatively, its status can be set using dipswitch 4).
OUT
SATMAX Off
max
min
setp
100%
100%
OUT
SATMAX On
max
min
setp
100%
100%
Fig. 6.c
Associated parameters
par. Spv Modb range def uom description
ESMX D4 4 0/1 0 1 Saturation function 0=disabled 1=enabled
Table 6.a.q
6.7 Speed-up function
When the output of the controller changes from zero to value greater than or equal to the minimum value set, the output is forced to the maximum value possible for a
time set by parameter (default 2 seconds). At the end of this time, the output returns to the required value, following the set ramp. The function has the purpose of
overcoming the inertia of the fans, allowing them to operate at low speeds that otherwise would not be possible when starting from standstill. By default the function is
enabled (alternatively, its status can be set using dipswitch 4).
Associated parameters
par. Spv Modb range def uom description
SUPT I13 113 1 to 5 2 1sec Speed-up duration
STEP I24 124 0 to 10 1 1sec Output ramp (minimum time for variation from 0% to 100%)
ESUP D2 2 0/1 1 1 Function Speed-up 0=disabled 1=enabled
Table 6.a.r
6.8 Outside temperature compensation (feedforward function)
The operation of the controller can be modified according to the temperature measured by probe B3, proportionally increasing the minimum output value set. This
function is especially useful when probes B1 and B2 measure temperature values because, as temperature probes are intrinsically slower to respond than pressure
probes, it brings forward the effects of any changes in the outside temperature, increasing the output as the outside temperature increases.