Model Definition

• D661 = Series (integrated 24 VDC electronics, NG10 mounting)

• 6405C = Spool/sleeve assembly; rated flow 30 L/min @ ΔP=35 bar (high‑response linear trim, no LVDT, standard null, C‑code configuration)

• Typical full config example: G30KOAO4NSF2‑A

  • G30 = 30 L/min rated flow & high frequency response

  • KOAO = Standard hydraulic layout, 24 VDC, ±10 V/±10 mA command, centered null

  • 4 = 4+PE connector, IP65

  • NSF2 = NBR seals, standard temperature range, standard pilot

  • A = Fail‑safe centering, no LVDT

Technical Specifications

Hydraulic Parameters

• Rated flow: 30 L/min (ΔP=35 bar)

• Max working pressure: 350 bar (P/A/B); 210 bar (internal drain T) / 350 bar (external drain T)Moog Inc.

• Step response: 6.5–10 ms (0→100%, 210 bar)Moog Inc.

• Hysteresis: <0.08%

• Resolution: <0.05%

• Null drift: <1.2% (ΔT=55 K)

• Null leakage: <6 mL/min

• Fluid cleanliness: NAS 1638 Class 6 / ISO 4406 18/15Moog Inc.

Electrical Parameters

• Power supply: 24 VDC (18–32 VDC)Moog Inc.

• Control signal: ±10 V (differential) or ±10 mAMoog Inc.

• Feedback: None (open‑loop)

• Connector: 4+PE, IP65

• Current draw: ≤600 mA

Physical & Environmental

• Operating temperature: −40 ℃ to +85 ℃

• Weight: approx. 5.2 kg

Interface & Communication Configuration

• Hydraulic interface: P/A/B/T, ISO 4401‑05 (NG10)Moog Inc.

• Electrical interface:

  • Power: 24 VDC, GND, PE

  • Command: ±10 V / ±10 mA

  • Status: Fault alarm output

Core Functions

• High‑Response ServoJet® Pilot: Optimized for 30 L/min, ultra‑fast response, excellent dirt tolerance

• Integrated PID Amplifier: Dead‑zone compensation, thermal/overload protection, stable null

• Open‑Loop Precision Control: High linearity and repeatability for cost‑effective motion control

• Fail‑Safe Centering: Spool returns to neutral on power loss

• 30 L/min Compact Flow: Ideal for small‑to‑medium systems requiring precision and speed

Application Scenarios

• Industrial automation: Small CNC machines, precision hydraulic presses, micro injection molding equipment

• Test equipment: Laboratory fatigue testers, small vibration tables, precision actuator test benches

• Metallurgy: Precision tension control, small‑duty AGC roll gap control

• Energy: Solar tracking systems, small wind turbine pitch control

Usage & Maintenance

• Installation: Horizontal/vertical mounting; minimize vibration

• Fluid: ISO VG46 mineral oil; maintain NAS 1638 Class 6 cleanlinessMoog Inc.

• Commissioning: Apply 24 VDC; connect ±10 V/±10 mA command; calibrate zero/gain

• Maintenance: Check contamination every 3 months; calibrate every 6 months; avoid long idle periods at high pressure