Woodward 9907-1106 Current to Pressure Converter

The Woodward 9907-1106 Current to Pressure Converter is the Class I Division 2 / ATEX Zone 2 version of Woodward’s CPC-II (Current-to-Pressure Converter, Enhanced Dynamics). It converts a 4–20 mA input current into a precise, stable hydraulic control pressure proportional to the setpoint, positioning steam and/or fuel valves and associated servo systems in turbine control applications — the CPC-II replacement for the original CPC 8901-455 (10 bar class).

Key Features

• 4–20 mA setpoint input converted to proportional hydraulic control pressure
• Positions steam / fuel valves and servo systems (Enhanced Dynamics version)
• 10 bar supply class: 0–10 bar(g) control pressure range (145 psi supply)
• Redundant setpoint / feedback input and redundant-link support for duplex configurations
• Configurable discrete outputs (NO/NC, short-circuit protected) and 4–20 mA analog output (feedback)
• Silt Buster™ anti-contamination impulse function with adjustable amplitude / period / duration
• PC Service Tool configuration (dynamic performance, pressure tracking, gain switching)
• Certifications: Class I, Div. 2 Groups A, B, C, D (T3); ATEX Zone 2, Cat. 3, Ex nA IIC T4

Technical Specifications

• Part Number: 9907-1106 (CPC-II; Enhanced version 9907-1200)
• Product Type: Current-to-Pressure Converter, Enhanced Dynamics
• Supply Voltage: 18–32 V DC, 24 V DC nominal (cable ≥ 3 mm² / 18 AWG)
• Power Consumption: 25 W steady state; 90 W transient (2 s max); supply must deliver 2 A continuous / 5 A peak
• Setpoint Signal: 4–20 mA into 200 Ω; 70 dB CMRR; common-mode ±100 V
• Redundant Input / Feedback: 4–20 mA into 200 Ω
• Analog Output: 4–20 mA; max external load 500 Ω; accuracy ±0.5% FS
• Discrete Outputs: Configurable NO/NC, 0.5 A @ 24 V DC (max 32 V DC); response <2 ms; short-circuit protected
• Supply Pressure (Hydraulic): 10 bar / 145 psi
• Control Pressure Range: 0–10 bar(g) / 0–145 psig (max setting <70% of supply for optimum dynamics; min ≥1 bar(g) above drain)
• Drain Pressure: max 2 bar or 30% of min control pressure
• Internal Leakage: max 14 L/min @ 25 bar inlet (10-bar model per pressure differential)
• Fluid: Mineral or synthetic oils; external supply filter 24–40 µm (β75); ISO 20/16 cleanliness; viscosity 20–100 cSt
• Cable Entries: 2 × 3/4″-14 NPT threaded ports
• Fuse / Breaker: max 6 A
• Certifications: Class I, Div. 2 Groups A, B, C, D T3; ATEX Zone 2, Category 3, Ex nA IIC T4
• Origin: United States

Installation Notes

1. Provide the 24 V DC supply (18–32 V) with 2 A continuous / 5 A peak capability and a 6 A protective device; the CPC-II has no input power switch — add a suitable breaker/switch.
2. Connect the 4–20 mA setpoint (and redundant setpoint/feedback if used) per the J1 wiring diagram; keep low-level signal cables separated from power cables.
3. Supply hydraulic oil to the supply port (10 bar / 145 psi); ensure supply pressure is stable to within ±5% of the minimum control pressure and the control pressure setting stays below 70% of supply.
4. Install conduit seals within 50 mm (2 in) of the conduit entry for hazardous-location compliance.
5. Commission with the PC Service Tool: set supply pressure, primary gain, and dynamic settings; verify control pressure tracks the setpoint before returning the valve to service.

Common Questions

What is the 9907-1106? It is the CPC-II current-to-pressure converter (Enhanced Dynamics) for Class I Div. 2 / ATEX Zone 2 areas, converting a 4–20 mA signal into a 0–10 bar hydraulic control pressure for steam/fuel valve positioning. It replaces the original CPC 8901-455 (10 bar class).

What is the difference between 9907-1106 and 9907-1200? 9907-1106 is the standard CPC-II version; 9907-1200 is the CPC-II “Enhanced” part number for the same 10-bar / Zone 2 class.

What power does it need? 18–32 V DC (24 V nominal), 25 W steady state with 90 W transient; the supply must handle 2 A continuous and 5 A for 2 seconds.

Which hazardous-area ratings apply? Class I, Division 2, Groups A, B, C, D (T3) and ATEX Zone 2, Category 3, Group II G, Ex nA IIC T4.