Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | Rexroth LT304 |
| Manufacturer | Bosch Rexroth (Indramat) |
| Product Type | Control Card / Servo Amplifier |
| Part Number | 0-608-750-085 |
| Supported System | Indramat System 300 |
| Function | Axis Control, Amplification, and Communication |
| Mounting | Standard System 300 Backplane Slot |
| Operating Temp | 0°C to 55°C (32°F to 131°F) |
| Diagnostics | LED Status Indicators |
| Origin | Germany |
Product Introduction
Rexroth LT304 serves as a critical control and amplification module within legacy Indramat System 300 architectures. It integrates servo amplification and control logic directly onto the backplane, allowing multi-axis motion control without requiring separate external drive units.Unlike generic replacement boards, the Rexroth LT304 handles precise motor commutation and feedback processing at the hardware level. Field experience shows these boards often fail due to aging electrolytic capacitors or degraded power transistors; our testing specifically targets power rail stability and signal integrity to prevent unexpected axis faults after installation.
Installation & Configuration Guide
Preparation (10 min)
- ⚠️ SAFETY: Lockout/Tagout the System 300 rack power. Wait 5 minutes for DC bus capacitors to fully discharge. Verify 0 VDC at the slot before touching connectors.
- Photo Record: Take a high-resolution photo of the existing Rexroth LT304 label. Focus on the part number
0-608-750-085and any hardware revision codes. (I once swapped a board assuming identical part numbers meant identical firmware, and the axis tuning parameters caused a runaway motor. Don’t be me.) - ESD Check: Wear a grounded wrist strap. The analog circuitry is highly sensitive to static discharge.
Removal (5–10 min)
- Loosen the top and bottom ejector screws evenly.
- Pull the module straight out. Do not rock it. Rocking bends backplane pins.
- Inspect the backplane connector for burnt pins or green corrosion. Clean with contact cleaner if needed.
Installation (10 min)
- Align the Rexroth LT304 with the slot guides. Ensure the ejector levers are fully open before insertion.
- Push firmly until the module seats. Tighten ejector screws to 0.5 Nm. (Overtightening strips the threads; undertightening causes vibration faults.)
- Verify no adjacent modules are displaced.
Power-On & Test (10 min)
- Restore backplane power.
- Observe LEDs: PWR (Green), RUN (Green), FAULT (Off).
- If FAULT blinks red: Check hardware revision and axis tuning parameters. Mismatched hardware is the #1 cause of post-install failures.
- Run a manual jog test at 10% speed to verify feedback polarity and motor commutation.
Troubleshooting Quick Reference
| Symptom | Probable Cause | Action |
|---|---|---|
| PWR Off, No LEDs | Backplane fuse blown or slot damage | Measure slot voltage. Inspect backplane pins for shorts. |
| FAULT LED Solid Red | Hardware mismatch or internal short | Verify part number 0-608-750-085. Check motor cables for shorts. |
| RUN Blinking, No Motion | Feedback loss or tuning error | Check resolver/encoder cabling. Verify axis tuning parameters. |
| Intermittent Axis Faults | Power line noise or aging capacitors | Check DC bus ripple. Replace if >15 years old. |
| Controller “Slot Fault” | Backplane connector damage | Inspect module edge connector for bent/missing pins. |
Dimensions, Mounting & Wiring Notes
- Form Factor: Standard Indramat System 300 Module
- Mounting: Vertical backplane insertion, secured by top/bottom ejector screws
- Wiring: No external field wiring. Motor power and feedback connect to dedicated System 300 terminal blocks.
- Clearance: Maintain 10 mm (0.4 in) clearance above/below for airflow.
- Connector: Custom System 300 DIN-style backplane connector
FAQ
Can I use a newer Rexroth LT304 revision in my old rack?
Maybe. Hardware revisions must match exactly for System 300 compatibility. Always verify the full part number 0-608-750-085 and any revision suffix against your existing board.I pulled the old board and lost the label. What now?
Do not guess. Check the controller’s online diagnostics; System 300 typically reports the expected module type. If the slot reads “Unknown,” you must power down and inspect the backplane for physical damage before installing a new unit.Is this module new or refurbished?
We sell both. “New Surplus” is factory-sealed but may be 10+ years old. “Refurbished” units undergo full capacitor replacement and 24-hour load testing. For critical motion control, I recommend Refurbished over aged New Surplus.Why does my Rexroth LT304 fail every 2 years?
Power quality or thermal stress. These boards are sensitive to DC bus voltage spikes and poor cabinet cooling. Install line reactors on motor drives and verify cabinet fans are operational. Replacing the module without fixing the environment is just buying a spare part.Do you have the tuning software for this?
The Rexroth LT304 uses legacy Indramat tuning tools. Configuration is typically done via Indraworks or System 300 diagnostic software. Contact support if you need the specific parameter set for your motor type.What’s the lead time on these?
Stock fluctuates weekly due to market harvesting. Current status is listed on the product page. If out of stock, we can source from certified partners in 3–5 days. Never accept “2 weeks” from a broker without a written guarantee.
