Rolls-Royce R984672C Voltage Transmitter

Rolls-Royce R984672C Voltage Transmitter Assembly

The Rolls-Royce R984672C Voltage Transmitter Assembly is a signal conversion and isolation instrument engineered for demanding commercial, naval, and offshore marine automation architectures. Designed specifically for propulsion feedback loops, remote pitch control, and hydro-jet steering monitoring, this unit converts raw electrical potential or transducer inputs into a standardized, noise-immune 4–20 mA current loop.

Manufactured under Rolls-Royce Marine automation standards (now integrated into Kongsberg Maritime propulsion control support), the R984672C is built to suppress common-mode electromagnetic interference (EMI) typical of marine switchboards, variable frequency drives (VFDs), and heavy hydraulic machinery. Housed in a ruggedized, vibration-damped marine-grade chassis, the transmitter ensures deterministic feedback control back to the wheelhouse control heads and machinery space remote alarm panels.

Model Details

• Manufacturer: Rolls-Royce Marine Systems / Kongsberg Maritime
• Equipment Type: Signal Conditioner & Voltage / Feedback Transmitter Assembly
• Model Code: R984672 Series
• Manufacturer Part Number (MPN): R984672C
• Assembly Revision: Rev. C

Key Features

1. Galvanic & Optical Isolation: Full 3-port isolation (input, output, and DC power rail) rated up to 1.5 kV AC, preventing ground-loop contamination between bridge consoles and engine room panels.
2. Wide Supply Compliance: Operates across nominal 12 V DC to 35 V DC auxiliary supplies, tolerating standard marine transients and battery-backed 24 V DC bus drops.
3. Vibration-Hardened Solid-State Architecture: Certified to withstand continuous vibration loads up to 4.0 g (5–100 Hz), preventing mechanical drift in high-vibration steering gear and waterjet compartments.
4. Fail-Safe Fault Detection: Implements NAMUR NE43 standard downscale (<3.6 mA) or upscale (>21.0 mA) output behavior upon sensor open-circuit, out-of-range signal, or internal loop fault.

Technical Specifications

Compatible Systems

• Rolls-Royce Kamewa Waterjet Steering & Reversing Gear: Interfaced with feedback control valves and deflector/bucket position sensors.
• Rolls-Royce / Ulstein Controllable Pitch Propeller (CPP) Systems: Remote pitch feedback transmitters for bridge telegraph and governor linkages.
• Rolls-Royce Helicon-X / CanMan Remote Control Systems: Analog input conversion modules.
• Tunnel Thrusters & Azimuth Drives: Steering angle and blade angle position feedback integration.
• Central Marine Automation Panels (AMS/IAS): Analog data acquisition for Kongsberg K-Chief, Lyngsø Marine, and Valmarine systems.

Applications

• Converting hydraulic deflector bucket feedback voltages into current signals for remote helm indicators.
• Pitch actuator feedback loop transmission over extended bridge-to-engine-room cable runs.
• Steering gear rudder angle transmitter (RAT) loop conditioning.
• Main engine governor reference speed and command setpoint transmission.

Part Number Cross-References

• Direct Predecessors: Rolls-Royce R984672A, R984672B
• Related Pitch/Position Units: R984664H, R984664A
• OEM Alternate References: KR0104121 series, Kongsberg Marine 984672C

Frequently Asked Questions

What does the Rolls-Royce R984672C transmitter assembly do?

The R984672C converts raw voltage or potentiometric feedback signals from propulsion units (such as waterjet steering deflectors or CPP pitch mechanisms) into an isolated 4–20 mA current loop for engine room automation and bridge consoles.

Can I replace an R984672B unit with the R984672C revision?

Yes. The R984672C is a backward-compatible revision of the earlier R984672A and R984672B models. It shares identical physical mounting footprints and primary terminal allocations, featuring upgraded internal noise filters and thermal stabilization components.

What causes loop failure on an active R984672C installation?

The most frequent causes are degraded 24 V DC auxiliary power supply ripple, improper single-point shield termination allowing variable frequency drive (VFD) interference, or ingress of hydraulic oil mist through unsealed cable glands.

How is zero and span adjusted on the R984672C?

Zero and span adjustments are accessible via the multi-turn trimpots located beneath the front inspection cover. Using an insulated trim tool, set mechanical zero at minimum stroke (4.00 mA), drive the actuator to 100% stroke, adjust the span pot to 20.00 mA, and repeat once to eliminate interactive adjustment offset.

Is this unit compatible with Kongsberg Maritime control systems?

Yes. Following Kongsberg’s acquisition of Rolls-Royce Commercial Marine, systems incorporating Kamewa and Ulstein equipment—including Helicon, CanMan, and K-Chief installations—maintain direct electrical compatibility with the R984672C module.