Core Information Extraction of Model 9907-165 (Woodward 505E Digital Governor)
1. Basic Positioning and Application Scenarios
Model 9907-165 is a specific variant of the Woodward 505E Digital Governor, a dedicated digital control device for extraction/admission steam turbines. Based on a 32-bit microprocessor design, its core function is to control the operating parameters of single-extraction, extraction/admission, or single-admission steam turbines. It features flexible field programmability, enabling adaptation to both generator-driven and mechanical-driven scenarios without hardware replacement to meet different control requirements. Beyond integrating speed regulation functionality, it also incorporates an Operator Control Panel (OCP), supporting standalone operation or linkage with a plant’s Distributed Control System (DCS) to reduce equipment costs and delivery cycles.
2. Compliance Requirements
2.1 Hazardous Location Certification
North America: UL Listed, suitable for Class I, Division 2, Groups A, B, C, D hazardous environments (T3C temperature rating at 60 °C ambient; UL File E156028), and also applicable to non-hazardous locations.
Europe: Compliant with EN60079-15 (Type of protection ‘n’), suitable for Zone 2, Group II potentially explosive atmospheres.
Note: Only equipment bearing the certification mark meets the above hazardous location usage requirements.
2.2 Directive Compliance
EMC Directive: Complies with 89/336/EEC and its amendments, meeting EN50081-2 (emission) and EN50082-2 (immunity) standards.
Low Voltage Directive: Complies with 73/23/EEC to ensure electrical safety.
ATEX Directive: Complies with 94/9/EEC, suitable for potentially explosive atmospheres.
2.3 Wiring Specifications
Must follow North American Class I, Division 2 or European Zone 2 wiring methods, and comply with the requirements of the local Authority Having Jurisdiction (AHJ).
If field wiring is used in environments where the ambient temperature is expected to exceed 50 °C, its rated temperature must be at least 75 °C.
Peripheral equipment must match the hazard level of the usage scenario to avoid safety risks.
3. Core Technical Parameters
3.1 Power Supply and Physical Characteristics
Power Supply Type: HVAC power, input voltage range 180–264 Vac (50/60 Hz). The internal power supply includes two circuit breaker-protected output channels: one (VA1) providing 24 Vdc ±10% (max 200 mA) for powering current inputs and auxiliary devices, and the other providing the same voltage and current specifications for powering current outputs and auxiliary devices.
Enclosure Rating: Standard enclosure meets NEMA 4/IP54; optional bulkhead-mounted enclosure (P/N 8923-439) meets NEMA 4X for enhanced environmental protection.
Operating Temperature: -25 to +65 °C (ambient air temperature for standard enclosure); -20 to +60 °C (ambient air temperature for optional bulkhead-mounted enclosure).
Weight: Approximately 4 kg (standard enclosure); approximately 10 kg (optional bulkhead-mounted enclosure).
3.2 Speed Sensing and Control Performance
Speed Inputs: Two speed inputs, jumper-configurable for Magnetic Pickup Units (MPUs) or proximity probes. For MPUs, the input impedance is 2 kΩ, with a minimum input amplitude of 1 Vrms (100 Hz–25 kHz) and 2 Vrms (25 kHz–32 kHz), and a maximum input amplitude of 25 Vrms. For proximity probes, speed can be sensed down to 0.5 Hz, with an input voltage range of 16–28 Vdc.
Speed Range: Sensing range 100 Hz–32 kHz; trip-point range 250 Hz–25 kHz (convertible to rpm via MPU gear teeth setting).
Trip Accuracy: ±(0.05% × Trip Point in Hz + 2 Hz).
MPU Fault Protection: Programmable MPU Fail Setpoint (100–25,000 rpm) and MPU Fail Timeout (1 sec–533 min 20 sec); triggers a trip if speed does not reach the setpoint within the timeout period.
3.3 Inputs and Outputs
Analog Inputs: 6 analog inputs in total. Input 1 is dedicated to extraction/admission signals; inputs 2–5 are configurable for signals like remote speed setpoint, synchronization, or kW load, and can be used with 2-wire loop-powered or self-powered transducers; input 6 is fully isolated, designed for non-isolated sources such as DCS, with an input impedance of 200 Ω for all inputs.
Contact Inputs: 16 contact inputs. 4 are dedicated (external emergency shutdown, external reset, raise speed setpoint, lower speed setpoint); 2 must be dedicated to generator breaker and utility tie breaker if used in generator applications; the remaining 10 (or 12 if not a generator application) are configurable. Each contact input draws 2.5 mA when closed, requiring at least 1 mA and 14 Vdc to recognize a closure.
Actuator Outputs: 2 actuator outputs, configurable for Woodward actuators (20–160 mA) or non-Woodward actuators (4–20 mA). Maximum impedance for 4–20 mA outputs is 360 Ω (actuator impedance + wire resistance); for 20–160 mA outputs, it is 45 Ω. Dither is available for both outputs, and an 11-point linearization curve is supported via Service Mode.
Relay Outputs: 8 Form-C relay outputs. 2 are dedicated (shutdown relay: de-energizes on shutdown; alarm relay: energizes on alarm); the remaining 6 are programmable for status indication (e.g., overspeed test, frequency control) or level switching (e.g., speed, extraction pressure).
Communications Ports: 2 Modbus ports (supporting RS-232, RS-422, RS-485; ASCII/RTU protocols) for interfacing with DCS or operator panels; 1 PC port for program configuration storage.
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