Description
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 88984-02 |
| Manufacturer | Bently Nevada |
| Product Type | Input Relay Option Card / Seismic Monitor Module |
| Compatible Systems | 3300 Series, 3500/42M, 3500/94M Overspeed Protection |
| Relay Outputs | 2 independent, Form C (SPDT), normally open contacts |
| Relay Type | Dry contact |
| Input Signal Range | 0-5V DC / 4-20mA |
| Output Signal | 4-20mA |
| Operating Temperature | 0°C to +65°C (relay card); -40°C to +85°C (seismic module) |
| Storage Temperature | -40°C to +85°C |
| Relative Humidity | Up to 95%, non-condensing |
| Mounting | Rear of monitoring rack / standard rack configurations |
| Certifications | CE, API 670 compliant |
| Country of Origin | USA |
Main Features and Advantages
Dual-Mode Versatility Across Platform Generations: The 88984-02 is unique among Bently Nevada components in its ability to serve two distinct functions depending on system configuration. In 3500 Series racks, it operates as a seismic monitor module within the 3500/42M family, providing four channels of absolute casing vibration measurement in a single slot. In legacy 3300 Series installations, the same 88984-02 designation functions as an input relay option card, providing the physical interface between monitoring channels and external alarm circuits. This dual identity reflects Bently Nevada’s commitment to backward compatibility and flexible system design, allowing engineers to standardize on a single part number across mixed-generation installations.
API 670 Compliance for Mission-Critical Protection: The 88984-02 meets the rigorous requirements of API Standard 670, the global benchmark for machinery protection systems in the petroleum, petrochemical, and natural gas industries. This compliance ensures that when the 88984-02 is deployed in turbine or compressor protection applications, it delivers the reliability, accuracy, and response time required to prevent catastrophic equipment failure. The module’s relay outputs are specifically designed for high-integrity trip functions, with contact ratings suitable for direct interface with emergency shutdown systems and safety instrumented functions.
Precision Signal Conditioning for Seismic Measurement: When configured as a seismic monitor, the 88984-02 provides exceptional measurement fidelity for casing vibration analysis. Its input circuitry accommodates standard Bently Nevada velocity transducers and accelerometers, converting their signals into 4-20mA outputs and digital data with minimal noise or drift. The 88984-02 achieves a response time of less than 10 milliseconds, ensuring that transient events and rapid vibration escalations are captured and communicated to the protection logic without delay. This fast response is critical for detecting blade pass anomalies, rotor rubs, and other high-frequency phenomena that can rapidly progress to destructive failures.
Simplified Integration and Maintenance: The 88984-02 is designed for straightforward installation at the rear of monitoring racks, with keyed connectors and labeled terminals that reduce wiring errors during commissioning or module replacement. Its compact form factor allows efficient use of rack space, and the module’s passive relay design means it draws no additional processing power from the rack backplane. When replacement is necessary, the 88984-02 can be exchanged without specialized calibration equipment in most configurations, minimizing mean time to repair and returning protection coverage to full capacity quickly.
