Description
Bosch Rexroth VT3024 | Proportional Valve Amplifier | Hydraulic Control
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product type | Electrical amplifier for proportional valves |
| Series | 3X |
| Supply voltage | 24 VDC, +60% / −5% |
| Supply operating range | 22–39 VDC |
| Power consumption | <1 A with load current |
| Command input | 0 to ±10 V differential |
| Command input resistance | 100 kΩ |
| Controlled voltage | ±9 V ±1%, 50 mA externally loadable |
| Solenoid output current | Maximum 800 mA |
| Bias current | 20 mA ±25% |
| Output-stage frequency | 170 Hz ±10% |
| Ramp-time setting | Approximately 30 ms to 1 s or 5 s |
| Connection | 32-pin DIN 41612 Type D terminal strip |
| Card size | 100 × 160 mm Euro-card |
| Front-panel dimensions | 3 HE; 128.4 mm high |
| Operating temperature | 0 to 50°C |
| Storage temperature | −25 to 85°C |
| Weight | Approximately 0.13 kg |
The values above come from the Bosch Rexroth VT3024 technical documentation. The manual specifies 24 VDC operation, ±10 V differential command input, dual pulsed-current outputs, and an 800 mA maximum solenoid current.
Product Introduction
The Bosch Rexroth VT3024 is an electrical amplifier used to control proportional hydraulic valves without electrical position feedback. Its intended valve applications include pilot-operated proportional directional valves such as 4WRZ and direct-operated proportional pressure valves including DBEP6 and 3DREP6.
The card combines differential command processing, a ramp generator, step-function generation, and two pulsed-current output stages. A positive command controls solenoid B while a negative command controls solenoid A, allowing the card to handle bidirectional proportional valve control from a single command signal.
VT3024
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
Legacy hydraulic machines often depend on a dedicated proportional amplifier rather than generating the required solenoid current directly from a PLC analog output. Replacing the VT3024 with a generic analog output card can therefore produce incorrect valve response, insufficient current, or unstable movement.
Typical Applications
- Proportional directional valve control — Used with compatible pilot-operated hydraulic valves such as the 4WRZ family.
- Pressure regulation — Suitable for specified proportional pressure valves including DBEP6 and 3DREP6.
- Machine-tool hydraulics — Useful where controlled hydraulic movement depends on ramped proportional current.
- Legacy hydraulic automation — Appropriate for machines retaining the original Rexroth amplifier/card-holder architecture.
Technical Pitfalls to Avoid
- Do not treat VT3024 as a normal 0–20 mA analog output. Its principal command input is a 0 to ±10 V differential input, while the valve outputs are current-controlled stages capable of up to 800 mA.
- Check the command polarity before commissioning. Bosch Rexroth specifies positive command value for solenoid B and negative command value for solenoid A. Reversing this relationship can produce the opposite hydraulic movement.
- Pay attention to the M0 reference. The documentation states that measuring zero is raised by +9 V relative to the 0 V operating supply and must not be connected directly to the 0 V operating supply. This is an easy mistake when troubleshooting with a modern PLC or test instrument.
- Do not install or remove the card while powered. The Rexroth documentation explicitly requires the amplifier card to be plugged in or unplugged only with power switched off.
- Verify the exact suffix. VT3024-3X is the documented Series 3X family, but field inventories also contain variants such as -S34 and -S35-R1. A replacement should be matched against the complete card marking, jumper configuration, and machine schematic rather than the base number alone. Current inventory records identify -S34 as a proportional amplifier card with ramp adjustment, while the Rexroth manual documents the broader -3X architecture.
Related Products
- VT3002-2X/32 — Single-card holder specified for the ; it does not provide the amplifier function itself.
- VT19083-1X — Associated NE30 power supply, converting 115/230 VAC to 24 VDC for the card system.
- VT3006 — Another Rexroth proportional amplifier family used in hydraulic valve control; application and electrical characteristics must be checked before considering substitution.
- VT3013 — Earlier Rexroth amplifier-card family appearing in legacy hydraulic control inventories.
- VT3014 — Legacy proportional amplifier family with different application/configuration characteristics.
- VT5003 — Rexroth proportional amplifier family; not a drop-in replacement simply because the function appears similar.
- VT5011 — Another Rexroth proportional amplifier family used for valve control; complete ordering code is required for compatibility assessment.
Procurement Note
For a replacement, the complete part marking is more important than the base model number. Confirm the Series 3X designation, suffix, jumper positions, card holder, valve type, solenoid resistance, command-voltage arrangement, and machine wiring before approving a substitute. The Rexroth manual specifically notes that the maximum solenoid current for a 19.5 Ω solenoid across its full temperature range requires at least 28 VDC, despite the nominal 24 VDC supply designation.
