Model Code Explanation (D661-4576C)

• D661: Series (ISO 4401‑05 mounting, integrated 24 VDC electronics)

• 4: 4‑way, zero‑lap, linear flow characteristic

• 57: Rated flow ≈ 100 L/min (Δp = 35 bar per land)

• 6: Standard‑dynamic response, single LVDT feedback, basic null stability

• C: Standard performance, non‑explosion‑proof

Technical Specifications

Part Number: D661-4576C

Mounting

Control Function

Hydraulic Parameters

• Rated Flow (Δp = 35 bar): 100 L/min (±8%)

• Max Operating Pressure (P/A/B): 350 bar (5,000 psi)

• Pilot Pressure (X): 21–280 bar (internal P or external X)

• T Port Pressure (Y internal): 210 bar; (Y external): 350 bar

• Fluid: Mineral oil (DIN 51524), viscosity 15–45 mm²/s

• Temperature: Ambient −20°C to +60°C; Fluid −20°C to +80°C

• Weight: Approx. 5.8–6.0 kg

Electrical Parameters

• Supply: 24 VDC (18–32 VDC), quiescent 230 mA, dynamic ~500 mA

• Command Signal: ±10 VDC (differential, 10 kΩ impedance) or 4–20 mA

• Feedback Signal: 4–20 mA (single LVDT spool position, ±0.02% FS accuracy)

• Connector: 6+PE (EN 175201‑804, IP65)

• Step Response (0→100%): 10–12 ms @ 210 bar (standard dynamics for 100 L/min)

• Hysteresis: <0.30% (closed‑loop)

• Linearity: <±0.40%

• Resolution: <0.05%

Interface & Communication Configuration

• Electrical: 6+PE connector; ±10 V command, 24 VDC power, 4–20 mA LVDT feedback

• Feedback: Single integrated LVDT (full‑stroke closed‑loop, high accuracy)

• Ports: P, A, B, T; optional external X (pilot) and Y (return)

• Seal Material: NBR (standard) or FKM (optional, high‑temperature)

Core Functions

1. 100 L/min Medium Flow: Balanced flow for general precision applications

2. Standard‑Dynamic Response: 10–12 ms step response, cost‑effective for 100 L/min

3. Reliable Closed‑Loop Control: LVDT feedback with low hysteresis for consistent positioning

4. ServoJet® Pilot: Jet‑pipe design reduces energy use, improves contamination resistance

5. Integrated Digital Amplifier: On‑board PID, ramp generator, fault diagnostics, EMC protection

Applicable Scenarios

• General Industrial Hydraulics: Standard stamping, blanking, and injection molding (cost‑sensitive)

• Basic Test Systems: Low‑frequency vibration tables, fatigue test rigs (moderate dynamics needed)

• General‑Purpose Machine Tools: CNC positioning, press brakes, standard machining centers

• Automation: Closed‑loop position/velocity control requiring good accuracy and low cost

Compatibility & Installation Notes

• Mechanical: Interchangeable with D661 (G/C/A), D662/D663 (ISO 4401‑05)

• Upgrade: Drop‑in replacement for D661‑4572C/4573C/4575C when standard dynamics suffice

• System Requirements: 24 VDC supply, analog controller (±10 V in / 4–20 mA out), ISO 4401‑05 manifold

Usage & Maintenance Instructions

1. Installation: Mount on flat surface (flatness ≤0.02 mm/100 mm; Ra <1 μm) with M6×55/60 bolts (13 Nm, diagonal)

2. Fluid: ISO VG 32–46, NAS 1638 cleanliness class ≤8

3. Maintenance: Replace internal filter every 5,000 hours; inspect leaks/connectors periodically

4. Precautions: Avoid voltage spikes/reverse polarity; do not open standard (C) models in field