Product Introduction
When critical gas turbine control systems require reliable relay switching, the Woodward 9905-973 Linknet 8 Channel Relay Module delivers robust performance. This Woodward 9905-973 module features eight independent relay channels, each capable of handling high-power loads. Designed for demanding industrial applications, the 9905-973 includes a Reset Button and Functional Fault LED for immediate status indication and recovery. As part of the Woodward Linknet family, this module ensures precise digital control in automation environments.
Technical Specifications
The following table lists critical parameters for the Woodward 9905-973:
| Parameter |
Value |
| Input Voltage Rating |
18-32 VDC, 27.4 A |
| Output Voltage Rating |
24 VDC, 16 A |
| Power Consumption |
14 W |
| Operating Temperature |
55°C |
| Weight |
9.11 lbs |
| External Dimensions |
8.75W x 14.625D x 5.375H |
| Power Supply Input |
18 to 32 V (dc) |
| Max Nodes per Bus |
64 (0 to +70 °C) |
| Network to I/O channel |
277 V (ac) |
| Potential Voltage Range |
80-150 |
| Signal to Actuator |
0 to 200 mA |
| Maximum Stub Length |
300 mm (+40 to +85 °C) |
| Network Isolation |
1000 Vrms (0–60 Hz) |
| Power Source |
95-130 |
| Speed Sensing |
1 to 30 Vac |
Industry Applications
The Woodward 9905-973 8-Channel Relay Module is primarily deployed in gas turbine control systems, where reliable signal routing and load switching are essential. Its robust design supports use in power generation, oil and gas, and industrial automation settings. The module's ability to handle 0 to 200 mA actuator signals and its wide input voltage range (18-32 VDC) allow it to interface with various field devices. For example, in a turbine fuel control loop, the Woodward 9905-973 manages multiple solenoid valves, while the Functional Fault LED instantly alerts operators to any relay failure, minimizing downtime.
Installation & Setup Guidance
Proper installation of the Woodward 9905-973 ensures reliable operation. Mount the module securely using its integrated mounting flanges (external dimensions 8.75 x 14.625 x 5.375 inches). Connect the power supply to the 18-32 VDC input terminals, observing polarity. Each relay output provides 24 VDC at up to 16 A; ensure connected loads do not exceed this rating. The Reset Button allows you to clear latched faults without cycling power. For bus communication, limit stub lengths to 300 mm to maintain signal integrity. After wiring, verify the Functional Fault LED is off before placing the system online.
Maintenance & Reliability
To maximize uptime with the Woodward 9905-973, perform periodic inspections focusing on the relay contacts and the Functional Fault LED. Check for any debris or corrosion on the terminals. The module's 14 W power consumption aids in low thermal stress, extending component life. The built-in Reset Button enables quick recovery from fault conditions, reducing the need for immediate replacement. Given the 9905-973's use in critical gas turbine applications, we recommend scheduled functional tests every six months to ensure all eight channels operate within the specified 0 to 200 mA actuator range.
Troubleshooting & Common Issues
Common issues with the Woodward 9905-973 relay module include failure of a single relay channel or a persistent fault indication. If the Functional Fault LED illuminates, first verify the input power is within the 18-32 VDC range. Try pressing the Reset Button to clear the fault. If the fault persists, check the connected load for shorts or overloads exceeding 16 A per channel. On the bus side, ensure the Network Isolation rating (1000 Vrms) is not compromised by improper grounding. For nodes per bus, do not exceed 64 devices. If problems continue, contact PLC Source PRO for technical support; the 9905-973 is kept in stock for fast replacement.