Page 24 - Linde - HPR-02 Self regulating pump for open loop operation

Controllers. E1L. Load Sensing with electric override

In addition to the load sensing function, the HPR-02 E1L offers an electric override for mode selection and power limit regulation
(underspeed control). The integration of all functions in the pump controller enables direct signal transfer without delays. The
controller-specific data are independent of the nominal pump size.

In the event of an electric override of the LS-signal, a pressure reducing valve is activated via the proportional solenoid. The
control pressure generated in this way acts proportionally against the LS-spring, and the effect of the ∆p LS signal is modulated
accordingly. This causes the pump to swash back, thereby reducing its output. The function between control current (l) at the
control solenoid and the associated ∆p LS value is shown in the diagram. At the port "A", the control pressure can be picked up and
forwarded to an H1L controller at another HPR pump, which follows the first pump with the E1L controller (master-slave-operation).

∆p LS-reduction E1L-controller

4
3

2
∆p LS [bar] 1

control current [mA] at 24V

control current [mA] at 12V

1 16 bar ∆p setting
2 20 bar ∆p setting
3 25 bar ∆p setting
4 28 bar ∆p setting

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