Carel srl: pCO Stage Controller
page 12
The parameter is visible only when the presence of the inverter on the device no.1/valve has been selected
(parameter P20). If the parameter SR4 is 1, the minimum aperture of the device 1/valve inverter (parameter Sr3) is
applied even if in case of alarm presence on this device or when (if P14=0) compressor 1 is Off. Only when the unit
is Off the output of the inverter/valve remains 0 in all cases.
SH1, SH2 - alarm threshold of high
It represents the threshold of high of the probe 1 and 2 respectively. When the value detected by the probe exceeds
the selected value the alarm is activated.
SL1, SL2 - alarm threshold of low
It represents the threshold of low of the probe 1 and 2 respectively. When the value detected by the probe falls
below the selected value the alarm is activated.
SC, dC, dt - set point, differential and compensation delta. See parameter P23.
P1, P24 - type of probes
The parameters makes it possible to specify the type of probes being used. The following selections are available.
0
probe is absent;
1
active temperature probe (-1V dc ÷ 1V dc);
2
temperature NTC probe;
3
pressure Keller probe 4-20 mA (Keller).
Depending on the selection it is necessary to connect the probes to the analog input B1 and B2 (passive
temperature probes) or B5 and B6 (pressure probes or temperature probes of the active type).
P2, P25 - probe lower range
These parameters are necessary when non-Carel probes have been selected (Keller probes or 4-20 mA probes).
They represent the lower operating limit of the respective probes. For instance, to the 4mA could correspond the 0
bar value, and so the 0 value must be attributed to the parameter.
P3, P26 - probe upper range
These parameters are necessary only when non-Carel probes have been selected (Keller probes or 4-20 m/A
probes). They represent the upper operating limit of the respective probes. For instance, to the 20 mA could
correspond the value of 30 bar, and so the value “30” must be attributed to the parameter.
P4 - probe 1 device number
The parameter represents the number of devices controlled by the probe 1 (except possible voltage control). The
device number may range from 0 to 11. When 11 devices are selected, it is not possible to connect any device to the
secondary circuit (except the fan inverter).
P5 - number of devices operating with probe 1 out of order
When occurring the alarm of broken or not connected probe 1 (AL14), the parameter P5 indicates the minimum
number of the circuit devices which are On.
P6 - number of voltage regulation
If the devices controlled by the probe 1 are compressors, it is possible to select the presence or not of one, two or
three stages of voltage regulation. If up to 5 compressors have been selected (P4=5), it is possible to use only one
stage of voltage regulation; while if up to 3 compressors have been selected (P4=3), it is possible to use 2 stage of
voltage regulation; while if up to 2 compressors have been selected (P4=2), it is possible to use 3 stage of voltage
regulation. This parameter is displayed only if P1>0 and P4>0 and if the functions “Device 1 Inverter” and “Neutral
Zone” have been not enabled at the same time (P14=0 and P20=1). Therefore the parameter is displayed in the
following cases: P1>0, P4>0, P14=0, P20=0; P1>0, P4>0, P14=1, P20=1.
P7 - logic of the voltage regulations
When voltage regulations are used, through this parameter it is possible to choose the operation logic of the outputs
dedicated to the voltage regulations (normally excited or normally deenergized).
P8 - minimum time between the turning on of successive voltage regulations of the same compressor.
It sets the minimum time needed between two successive voltage regulations, or between the starting of the
compressor and the respective voltage regulation. The parameter is present only if the regulations have been selected
(P6>0).
P9 - logic of the voltage regulations turning on - full or partial
FULL: the ON sequence is COMP.1
→
PARZ.1
→
COMP2
→
PARZ.2 etc...While the OFF sequence is PARZ.2
→
COMP2
→
PARZ.1
→
COMP.1
PARTIAL:in the ON sequence the partializations will be activated as soon as all the compressors are On. In the OFF
sequence the compressors are turned Off when the all partializations are already Off.
P10 - turning on minimum time of the probe 1 devices
It sets the turning on minimum time of the circuit 1 devices. As a consequence, when all the circuit devices have been
activated, they must remain oN for the same lenght of time as the one selected by the above-mentioned parameter.
ON
OFF
P10
ON
OFF
request
device
Fig. 7
P11 - turning off minimum time of the probe 1 devices