VT-VRRA 1-527-20/V0

The VT-VRRA 1-527-20/V0 is an electronic amplifier card produced by Bosch Rexroth Indramat within the VT-VRPA Electric Amplifiers series. Supplied as a plug-in board, the unit conditions command signals for a proportional directional valve in automated hydraulic machinery. This function allows a higher-level controller to regulate fluid flow and pressure through electrical commands. The card is suitable for hydraulic systems that require responsive valve control from a centralized control rack.

The card accepts a differential command range of 0 to 10 V, allowing standard PLC analog outputs to drive the circuit without additional scaling hardware. Its output stage is tuned for the 4WRPH6.L-2X proportional valve, matching the coil impedance and dynamic response to support stable spool positioning. The card uses a printed circuit board format and slides into a rack or subassembly that houses the hydraulic power unit’s control electronics. Field wiring is consolidated on a 32-pin form F connector plug, which provides separate contacts for command, feedback, and supply lines while maintaining a compact arrangement. Internal processing uses an analog signal path, keeping the signal continuous between the controller and valve. The design provides one solenoid channel for single-sided valve actuation, reducing output-stage heat and simplifying control-loop adjustment.

Nominal control power is supplied at 24 VDC, which is compatible with common low-voltage control devices used in industrial enclosures. This supply arrangement allows the amplifier to operate from the same control-power distribution used by other rack-mounted electronics. With a mass of 0.36 kg, the module places little mechanical load on its card guides and supporting rack. Its plug-in arrangement also provides direct access to the connector and board when the enclosure is opened for inspection or maintenance.