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Beschikbare talen
Beschikbare talen
5.13
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, shown in Figure 16 Regulating: Imax, SP and
DP, 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.
5.14
System operation
Pressure switches:
The operating logic is the following:
P1
P2
Pressure switch connected to input B starts and stops Pump 1
•
Pressure switch connected to input C starts and stops Pump 2
•
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 Figure 17 and Figure 18.
The operating logic is the following:
Pumps
P1
P2
Pumps
Figure 15: Enabling P1 and P2.
Figure 16: Regulating: Imax, SP and DP
Pressure boosting operation with pressure switches
Start
Pressure switch B = CLOSED
Pressure switch C = CLOSED
Table 2: Pressure boosting operation with pressure switches
Pressure boosting operation standard vessel < 100 litres
Start
System pressure <= SP
System pressure <= SP – RP/2
Table 3: Pressure boosting operation standard vessel < 100 litres
Operation with additional expansion vessel > 100 litres
Start
ENGLISH
Stop
Pressure switch B = OPEN
Pressure switch C = OPEN
System pressure => SP+RP
System pressure => SP+RP
77
Stop
Stop
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