Bosch Rexroth RKP-PQ Hydraulic Amplifier Card

Bosch Rexroth RKP-PQ Hydraulic Pump Amplifier Card — Stop the Bleeding. Ship Today.

Every hour your hydraulic press, injection molder, or rolling mill sits idle, you’re burning money. The Bosch Rexroth RKP-PQ is the dual-channel pressure/flow amplifier card that drives the variable-displacement RKP radial piston pump — and when it fails, nothing downstream works. We stock it in Xiamen. We ship it today. DHL Express to your dock in 24–72 hours depending on your region. No waiting on factory lead times. No broker runaround.

This is not a generic substitute. This is the genuine Bosch Rexroth RKP-PQ, sourced from verified OEM channels, inspected before dispatch, and backed by a 90-day replacement guarantee. If your line is down, this is the call you make.

URGENT REQUIREMENT? Contact: [email protected] | WhatsApp: +86 18359268345

Quick Technical Datasheet

Troubleshooting & Replacement Tips

Common failure signatures for the RKP-PQ card:

• Pump output pressure collapses to zero or max-rails — The pressure channel’s output transistor has failed open or shorted. Measure solenoid coil resistance at the pump (typically 20–40 Ω). If coil is intact, the card is the culprit.
• Flow setpoint ignored — pump runs at fixed displacement — Flow channel command input stage failure. Check the 4–20 mA or ±10 V signal at the card terminal first. If signal is present and correct, the card’s DAC or output driver is gone.
• Erratic pressure hunting / oscillation — Before condemning the card, check dither frequency and amplitude trimmers. Incorrect dither settings cause valve hysteresis issues that mimic card failure. If trimmer adjustment doesn’t stabilize, the card’s internal reference is drifting — replace it.
• Enable input active but no solenoid current — Internal enable relay or optocoupler failure. Verify 24 V supply is within ±10%. Undervoltage lockout trips at approximately 20 V.
• Fault LED lit, no output — Check for short circuit on solenoid wiring. The card has overcurrent protection; a wiring fault will latch the output off. Clear the fault by cycling 24 V power after fixing the wiring.

Step-by-step replacement procedure:

1. Document current potentiometer positions — Before pulling the old card, photograph or record all trimmer settings (ramp up, ramp down, dither frequency, dither amplitude, gain). These are machine-specific and not stored digitally.
2. De-energize and lock out — Isolate 24 V DC supply. Confirm zero voltage at card terminals. Hydraulic pressure should be at zero before disconnecting solenoid wiring.
3. Label all wiring — The RKP-PQ terminal block is removable on most variants. If yours is not, photograph the wiring before removal. Pay attention to command signal polarity — reversed ±10 V will drive the pump to max displacement on power-up.
4. Jumper configuration check — The new card ships in a default jumper state (typically voltage input mode). Verify your machine uses voltage or current command and set jumpers accordingly before installation. Refer to Rexroth datasheet RE 30028 for jumper map.
5. Restore trimmer settings — Transfer your documented settings to the new card before power-up. Start with ramp times at maximum (slowest) and tighten from there during commissioning.
6. Power-up sequence — Apply 24 V with command signal at zero. Confirm enable input is active. Slowly increase command signal while monitoring pump pressure and flow. Adjust gain trimmer if response is sluggish or oscillatory.
7. Dither optimization — Set dither frequency to 100–200 Hz range as a starting point. Increase amplitude until valve hysteresis is eliminated without causing audible buzz in the pump. Lock trimmers with nail varnish once optimized.

Configuration notes specific to RKP-PQ: Unlike some Rexroth amplifier cards, the RKP-PQ does not support fieldbus parameterization — all settings are hardware-only via on-board trimmers and jumpers. There is no firmware to flash and no address switch to set. This is both its strength (no software dependency) and its limitation (no remote diagnostics). Keep a spare card pre-configured to your machine’s settings to cut future downtime to under 15 minutes.

Reliability in Harsh Conditions

The RKP-PQ was designed for the floor, not the lab. Bosch Rexroth’s industrial amplifier cards are validated against the conditions that actually kill electronics in hydraulic control panels:

• Vibration — Tested to IEC 60068-2-6 sinusoidal vibration profiles. The PCB uses conformal coating and through-hole components in critical signal paths to resist solder joint fatigue from continuous machine vibration. Surface-mount components are selected for vibration-rated packages.
• Thermal cycling — Hydraulic control panels routinely swing from cold-start ambient (as low as −10 °C in unheated facilities) to 55 °C operating temperature within minutes of machine start. The RKP-PQ’s components are rated for this thermal shock without parameter drift.
• Humidity and condensation — Conformal coating on the PCB provides protection against humidity ingress. In coastal or high-humidity environments (marine, food processing, tropical climates), the card maintains stable operation up to 95% RH non-condensing.
• Electrical noise — Hydraulic solenoids generate significant inductive kickback. The RKP-PQ’s output stage includes freewheeling diodes and transient suppression to protect the driver circuitry from solenoid switching spikes. EMC compliance per EN 61000 series ensures the card does not radiate interference into adjacent control equipment.
• Power supply transients — The 24 V input is protected against reverse polarity and transient overvoltage. Brief supply interruptions (< 20 ms) do not cause output glitches due to internal hold-up capacitance.

Units supplied by siemensplc.com are stored in climate-controlled conditions and shipped in anti-static, foam-lined packaging with humidity indicator cards. What arrives at your facility is in the same condition it left the factory.

Global Express Logistics

Our Xiamen warehouse is positioned for fast export to every major industrial region. Here’s how the process works from the moment you confirm your order:

• Same-day dispatch — Orders confirmed before 15:00 CST ship the same business day. Orders after 15:00 ship next morning.
• Carrier selection — We use DHL Express and FedEx International Priority as primary carriers. Carrier is selected based on your destination for fastest transit time, not lowest cost.
• Transit times (estimated):
  • Southeast Asia (Vietnam, Thailand, Indonesia, Malaysia): 1–2 business days
  • South Asia (India, Pakistan, Bangladesh): 2–3 business days
  • Middle East (UAE, Saudi Arabia, Turkey): 2–4 business days
  • Europe (Germany, Poland, Italy, Spain): 3–5 business days
  • North America (USA, Canada, Mexico): 3–5 business days
  • South America (Brazil, Chile, Argentina): 5–7 business days
  • Africa: 5–8 business days
• Export documentation — Commercial invoice, packing list, and certificate of origin provided with every international shipment. HS code 8537.10 declared. We handle export customs clearance from China.
• Tracking — AWB number sent via email within 2 hours of dispatch. Real-time tracking link provided.
• Import duties — Buyer is responsible for import duties and local customs clearance. We can provide DAP or DDP terms for select destinations — contact us to discuss.
• Emergency freight — For critical line-down situations, we can arrange next-flight-out courier on request. Contact us via WhatsApp for fastest response.

Contact Information

📧 Email: [email protected]
💬 WhatsApp: +86 18359268345
🌐 Web: siemensplc.com
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