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Beschikbare talen
Beschikbare talen
8.16
Regulating the rated current of the pumps (Imax), Set point (SP) and differential restarting pressure (DP)
With a straight tip screwdriver, position the indices in the centre of the graduated scales, as shown in Figure 53, so that:
Imax indicates the rated current of the installed pumps, which you can find on the pump data plate.
•
SP indicates the desired set point pressure.
•
DP is the pressure variation, in percentage of the set point, necessary to restart the pumps.
•
Attention, the differential restarting pressure is calculated as SP * DP. If the set point is 4 bar and DP is 50%, the
pressure differential RP is 2 bar.
8.17
System operation
Pressure switches:
The operating logic is the following:
Pressure switch connected to input B starts and stops Pump 1.
•
Pressure switch connected to input C starts and stops Pump 2.
•
P1
P2
Pressure sensor:
RP is the pressure differential, and indicates the pressure variation around the Set Point for which the pumps are switched on. In
systems with a display it is set directly. In systems without a display, DP is set as a percentage of the Set Point. RP = SP*DP. For
further information see Figures 54 and 55.
The operating logic is the following:
The first pump starts when the pressure falls below the Set Point and it stops when it reaches the Set Point pressure + RP.
•
The second pump starts when the pressure falls below the Set Point minus RP, or 2% of the Set Point if vessels over 100
•
litres are used. It stops when the set point pressure + RP is reached in the system.
Pumps
P1
P2
Pumps
P1
P2
Attention: If DIP SWITCH configuration is used, the differential restarting pressure is calculated as SP * DP. If
the set point is 4 bar and DP is 50%, the restarting pressure RP is 2 bar.
The names pump P1 and P2 are only indicative. If exchange mode is activated, the pumps P1 and P2 are
alternated as specified in the exchange mode.
The two pumps will always be started alternately with a minimum interval of 2 seconds from each other.
Example of Regulation with Standard expansion vessel and Regulation with additional expansion vessel:
SP= 4 bar
RP = 2 bar Attention: if DP is set (with the trimmers) RP=SP*DP
Figure 53: Regulating the rated current SP and DP
Pressure boosting operation with pressure switches
Start
Pressure switch B = CLOSED
Pressure switch C = CLOSED
Table 11: Pressure boosting operation with pressure switches
Pressure boosting operation standard vessel < 100 litres
Start
System pressure <= SP
System pressure <= SP – RP
Table 12: Pressure boosting operation standard vessel < 100 litres
Operation with additional expansion vessel > 100 litres
Start
System pressure <= SP
System pressure <= SP – 2%
Table 13: Operation with additional expansion vessel > 100 litres
ENGLISH
98
Stop
Pressure switch B = OPEN
Pressure switch C = OPEN
Stop
System pressure => SP+RP
System pressure => SP+RP
Stop
System pressure => SP+RP
System pressure => SP+RP
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