System Operation; Pressure Switches; Pressure Sensor; Table 2: Pressure Boosting Operation With Pressure Switches - DAB E.Box Plus Instrucciones De Instalación Y Mantenimiento

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
P1
P2

The first pump starts when the pressure falls below the Set Point and it stops when it reaches the Set Point
pressure + differential restarting pressure.

The second pump starts when the pressure falls below the Set Point minus half the differential restarting
pressure, or 2% of the Set Point if vessels over 100 litres are used. It stops when the pressure in the system
reaches the Set Point pressure + differential restarting pressure.
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 indications 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
Figura 17: Regulation with expansion vessel < 100 litres
Pressure boosting operation with pressure switches
Start
Pressure switch
CLOSED
Pressure switch
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
System pressure <= SP
System pressure <= SP – 2%
Table 4: Operation with additional expansion vessel > 100 litres
ENGLISH
Stop
B = Pressure switch B = OPEN
C = Pressure switch C = OPEN
System pressure => SP+RP
System pressure => SP+RP
System pressure => SP+RP
System pressure => SP+RP
Figura 18: Regulation with expansion vessel > 100 litres
83
Stop
Stop