fig.2:
Calculating the step time
Example: Process value = 8 The step time is derived as shown and is 75 secs.
PV
Process value (= 8)
SP
Setpoint (=6)
NZ
Neutral Zone (=2)
PZ
Proportional Zone (=6)
CPZ
Correction P Zone (=0.5)
t1
Camin (=50)
t2
Camax (=100)
t3
Capacity -max (=60)
t4
Capacity -min (=30)
1.2
Explanation of the parameters of sequence control options
Operation mode
Master/
Slave/ Off
One compressor must be chosen as Master and the other compres-
sors as Slaves. "off" means not under sequence control.
Sequence number
1 to 9
Each compressor must have a different number.
Minimum
1
%
Compressor must be able to reach this capacity, sequence control
may force compressor to hold this capacity.
Part load
1
%
Compressor must be able to reach this capacity, sequence control
may force compressor towards part load and to hold this capacity.
For screw compressors with Vi, the value for the part-load should be
set not higher than 70%.
Maximum
1
%
Compressor must be able to reach this capacity, sequence control
may force compressor towards maximum and to hold this capacity.
Parameters
Operating Manual | Sequence Control for Packages
GSC TP
12
GEA Refrigeration Germany GmbH | E_301510_2 | Generated 17.12.2014