RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Commissioning |
Pressure and flow control system SYDFE1 series 2X, 3X
67/96
8.1.8 Bleeding the pre-load valve
WARNING
Case interior under high pressure!
Risk of injury! Loosening the screw too far can cause parts and jets of hydraulic
fluid to be ejected.
▶ Do not turn the bleed screw out too far (max. 2 turns)!
If a pump unit is operated with a pre-load valve, this valve has to be air-bled
for the initial start-up, provided that the pump does not deliver and aspire oil.
Bleeding is not required, when the pump displaces oil. Bleed the pump while the
system is running at low operating pressure. To this end, loosen the screw (see
Figure below) by a maximum of 2 turns and wait until bubble-free oil flows out.
Then, re-tighten the screw.
Bleed screw
Fig. 32: Bleeding the pre-load valve
8.1.9 Adjusting the operating pressure
The operating pressure is the pressure level that the pump system is to generate
as maximum value in the system. The control electronics converts the signal level
of the pressure transducer connected to the pump system into the normalized
level of 0...10 V and passes this actual pressure value on to the pressure
controller. The converted actual pressure value can be measured at test jack 2.
Depending on the signal output of the pressure transducer, the signal adjustment
(switch S2) of the control electronics must be preset.
The factory setting of signal adjustment is configured to the signal range of 0…+10
V.
Some examples:
• 4...20 mA is converted into 0...10 V
• 1...10 V is converted into 0...10 V
The pressure controller of the VT 5041-3X compares the level at the command
value input (0...10 V; test jack 1) with the converted actual pressure value (0...10
V; test jack 2).
If the measuring range of the pressure transducer does not correspond to
the operating pressure, it is not the operating pressure value that is used for
