Bosch Rexroth VT-VPCD Series Operating Instructions Manual page 16

16/60 About this product
B A
MB MA
E
U M1 R5R6R7
Pump combinations
(master/slave)
Bosch Rexroth AG, VT-VPCD, RE 30028-B/09.13
Hyquip Limited New Brunswick Street Horwich Bolton Lancashire BL6 7JB UK
Company Registered in England No: 4167649 VAT Registration No: 732 5692 25 BS EN ISO 9001:2008 No: LRQ 0964389
T P
b a
b B A a
K3 K2 T R(L) R4 R3 R2 M2
Fig. 2: Pump control in the closed circuit with connection of the swivel angle transducer
Optionally, a by-pass valve Z4WEH (WB152) (4/2 directional shut-off valve) can be
installed additionally between the sandwich plate and the proportional valve.
The by-pass circuit does not feature an emergency stop function! The by-pass
circuit serves for adjustment and setting purposes in the de-pressurized zero
position, but without a defined return during high-pressure operation.
When several pumps deliver fluid into a system, they have to be connected in
parallel. If pressure control is to be activated for them, it is useful to apply the
master/slave principle. To this end, one pump is used as master, and all the other
pumps are hooked up as slaves. One pressure transducer can be connected to
several control electronics. In the case of pressure sensors with current interface,
the resulting load impedance must be taken into account (load impedance per
control electronics 100 Ω). The voltage drop across an input is 3.5 V at 20 mA and
1.7 V at 4 mA. The master board realizes closed-loop swivel angle control as well as
closed-loop pressure control and power limitation. For this, the swivel angle,
pressure and power command values have to be provided accordingly.
The swivel angle command value (b2) of all slave boards is to be connected to the
output (d32) of the master board.
For master/slave operation, the swivel angle command value (b4) of all slave boards
must be connected to the output (b28) of the master board.
The pressure controller must then only be adapted on the master board. The slave
boards are always operated using the resulting command value of the master board.
+44 (0)1204 699 959
enquiries@hyquip.co.uk
www.hyquip.co.uk/web/index
Short-circuit valve, optional
(+)
CLOCKWISE direction of rotation
Rkv
COUNTER-CLOCKWISE direction of rotation
Rkv
S
U
Sp
P
Sp
P