Woodward 5448-906 REVSPM-D10

Model Series

Woodward 5400 Series Digital Speed/Load Controllers

Related models in the 5400 series include:

• Woodward 5448-101 — Base 5448 speed controller, single-input
• Woodward 5448-102 — 5448 with dual speed input
• Woodward 5448-201 — 5448 with load control and synchronization
• Woodward 5448-906 — 5448 with integrated PMG (Permanent Magnet Generator) input, REVSPM-D10 revision
• Woodward 5466 — Next-generation EasyGen-3500 controller (successor platform)
• Woodward 505E — Legacy analog speed controller (replaced by 5448 series)
• Woodward 505F — Legacy analog speed controller with fuel limiter (replaced by 5448 series)

Manufacturer

Woodward, Inc.
Hexatronic Group AB
Address: 1000 East Drake Road, Fort Collins, CO 80525, USA
Parent Company: Hexatronic Group AB, Drottninggatan 89, 111 60 Stockholm, Sweden

Technical Specifications

Functional Features

• Permanent Magnet Generator (PMG) speed sensing — accepts variable frequency PMG input from 400 Hz to 1600 Hz, enabling operation across the full speed range without external tachometer
• Isochronous and droop speed control — switchable between 0% droop (isochronous) and 10% droop for single-machine or parallel operation
• Automatic load sharing — when multiple generators operate in parallel, the controller automatically adjusts fuel to maintain equal load distribution within ±1%
• Auto-synchronization — matches voltage magnitude, frequency, and phase angle before closing the breaker, with adjustable synchronizing time window of 0.1 s to 30 s
• Fuel limiting — programmable maximum and minimum fuel limit to protect the engine from overspeed or stall conditions
• Programmable acceleration/deceleration ramps — adjustable ramp rates from 0.1%/s to 100%/s for controlled startup and shutdown
• Engine protection — includes overspeed trip, underspeed trip, overtemperature trip, low oil pressure trip, and high exhaust temperature trip with configurable setpoints
• Governor mode switching — supports Speed Control, Load Control, and Isochronous modes selectable via front panel or remote signal
• Remote monitoring — RS-485 Modbus RTU interface enables remote reading of speed, load, fuel position, and alarm status from a SCADA system or HMI
• Event logging — internal non-volatile memory stores the last 256 events with timestamps for post-event analysis

Performance Parameters

Material Composition

Structural Characteristics

• Form Factor: DIN rail or panel-mountable controller with integrated front panel interface
• Front Panel Layout:
  • 16 × 2 character LCD display — shows speed, load, fuel position, mode, and alarm status
  • 4 × push-button navigation keys — menu navigation, parameter adjustment, mode selection
  • 2 × rotary potentiometers — speed setpoint and load setpoint (optional, depending on configuration)
  • 6 × LED indicators — power, run, alarm, trip, sync, and communication status
  • 2 × mini-DIN connectors — RS-485 and RS-232 communication ports
  • 1 × DB-15 connector — analog I/O and digital I/O breakout
• Rear Panel:
  • 2 × 4-pin terminal blocks — PMG speed input (A+, A−, B+, B−)
  • 1 × 8-pin terminal block — fuel servo output (4 to 20 mA)
  • 2 × 6-pin terminal blocks — digital inputs and relay outputs
  • 1 × 4-pin terminal block — 24 VDC power input
• Internal Layout:
  • Main processor board — mounted vertically on the left side of the enclosure
  • Power supply module — isolated DC-DC converter, mounted on the right side
  • I/O terminal boards — removable plug-in modules for analog and digital I/O
  • Communication module — removable RS-485/RS-232 board with opto-isolation

Working Principle

1. Speed Sensing: The PMG (Permanent Magnet Generator) mounted on the engine shaft generates a three-phase AC voltage whose frequency is directly proportional to engine speed. The 5448-906 accepts this signal on the PMG input terminals (A+, A−, B+, B−) and measures frequency from 400 Hz to 1600 Hz
2. Frequency-to-Speed Conversion: The internal microprocessor converts the PMG frequency to engine speed in RPM or Hz using the formula: Speed (RPM) = (Frequency × 60) / Number of PMG poles
3. Error Calculation: The measured speed is compared against the speed setpoint (entered via front panel potentiometer or remote signal). The difference is the speed error signal
4. PID Control: A digital Proportional-Integral-Derivative (PID) controller processes the speed error and generates a fuel demand signal (4 to 20 mA) proportional to the required fuel flow
5. Fuel Servo Actuation: The 4 to 20 mA signal drives the fuel control valve servo motor, which adjusts the fuel rack position to increase or decrease fuel flow
6. Load Control Mode: When in load control mode, the controller compares actual load (from a 4 to 20 mA load transducer) against the load setpoint and adjusts fuel to maintain the desired load
7. Droop Compensation: In droop mode, the speed setpoint is automatically reduced as load increases according to the configured droop percentage, enabling stable parallel operation
8. Synchronization: During auto-sync, the controller compares the generator voltage frequency and phase against the bus voltage. When all three parameters (voltage, frequency, phase) are within the configured window, the controller sends a breaker close command via a relay output
9. Protection Monitoring: The controller continuously monitors all protection inputs (overspeed, underspeed, temperature, pressure). If any parameter exceeds its trip setpoint, the controller immediately commands a fuel cut and breaker open

Advantages and Highlights

• Digital architecture — replaces legacy analog 505/505E controllers with superior accuracy, repeatability, and diagnostic capability
• PMG input eliminates tachometer — direct PMG connection removes the need for a separate magnetic pickup or optical tachometer, reducing installation cost and failure points
• Auto-synchronization — fully automatic paralleling with adjustable deadband eliminates manual synchronization procedures
• Event logging — non-volatile memory retains the last 256 events for root-cause analysis after a trip or alarm
• Field-upgradeable firmware — software updates are performed via RS-232 or USB without removing the controller from the panel
• Wide operating temperature range — -20°C to +60°C covers outdoor installations in arctic, desert, and tropical climates
• IP54 front panel rating — dust and splash-proof front panel suitable for industrial environments
• Long lifecycle guarantee — Woodward guarantees minimum 15-year product availability for the 5448 series
• Modbus RTU communication — standard protocol enables seamless integration with any SCADA, DCS, or HMI system
• Drop-in replacement for 505E — identical footprint and wiring harness compatibility simplifies migration from analog to digital

Applicable Industries

Installation Requirements

• Installation must be performed by qualified electrical technicians trained in Woodward controller wiring
• The controller must be mounted on a vertical DIN rail (35 mm) or panel-mounted using the four corner mounting holes
• Power supply wiring: Connect 24 VDC (18–32 VDC) to the rear panel terminal block with minimum 14 AWG copper wire. Do not exceed 32 VDC
• PMG wiring: Connect PMG output (A+, A−, B+, B−) to the rear panel PMG terminals using shielded twisted pair cable. Shield ground must connect to chassis ground at one end only
• Fuel servo wiring: Connect the 4 to 20 mA output to the fuel servo motor using shielded cable. The servo motor impedance must be 250 Ω to 750 Ω
• Grounding: The controller chassis must be connected to equipment ground with a wire size no smaller than 10 AWG copper
• Ambient temperature: Ensure the installation location maintains temperature within -20°C to +60°C. Do not install in direct sunlight or near heat sources exceeding 70°C
• Ventilation: Provide minimum 10 cm (4 inches) clearance above and below the controller for natural convection cooling
• Cable routing: Keep signal cables (PMG, analog I/O) separated from power cables by a minimum of 15 cm (6 inches) to prevent electromagnetic interference
• After installation: Perform a full functional test using the front panel menu to verify speed sensing, fuel output, and protection functions before energizing the engine

Usage Precautions

• Do not exceed 32 VDC on the power input — overvoltage permanently damages the internal DC-DC converter
• Do not connect PMG input when the engine is rotating above 120% speed — overfrequency input damages the speed measurement circuitry
• Do not short the 4 to 20 mA fuel output — a short circuit causes the fuel servo to drive to full stroke, resulting in engine overspeed
• Do not disconnect the PMG signal while the engine is running — loss of speed signal causes the controller to trip on underspeed protection
• Do not modify the firmware without Woodward authorization — unofficial firmware changes void the certification and warranty
• Do not operate the controller in environments with corrosive gases (H₂S, Cl₂) without an NEMA 4X enclosure — corrosion degrades terminal contacts and PCB traces
• Do not cover the front panel ventilation slots — blocked airflow causes internal temperature to exceed the +60°C limit, leading to thermal shutdown
• Do not use the relay outputs to switch inductive loads exceeding 5 A without a snubber circuit — inductive kickback damages the relay contacts
• Calibrate the PMG input annually — PMG output voltage drifts over time, affecting speed measurement accuracy
• Replace the controller at end of lifecycle (15 years from manufacture date) — component obsolescence and capacitor aging degrade long-term reliability
• Store spare units in a dry environment at 5% to 85% RH — moisture ingress causes PCB corrosion and conformal coating delamination

Part Number Decoding

Document Reference

• Manufacturer: Woodward, Inc., 1000 East Drake Road, Fort Collins, CO 80525, USA
• Parent Company: Hexatronic Group AB, Drottninggatan 89, 111 60 Stockholm, Sweden
• Technical Manual: Woodward Publication 82700 (5448 Controller Installation and Operation Manual)
• Applicable Standards: ISO 8528-5, ISO 8528-9, IEC 60034, IEEE 1547, NFPA 85, NFPA 70 (NEC)
• Replacement Part Numbers:
  • 5448-101 — Base speed control (no PMG)
  • 5448-201 — Load control with synchronization
  • 5466-001 — Next-generation EasyGen-3500 controller (recommended successor)
• Communication Protocol: Modbus RTU, Slave Address 1 (default), Baud Rate 9600–115200 bps
• Software Version: Field-upgradeable, current version: 3.2.x (verify at time of installation)