The GE / Bently Nevada 81545-01 is a transducer I/O and relay interface module for the Bently Nevada 3300 Series Monitoring System. This signal input/alarm output board provides dual epoxy relays and terminal connectivity for transducer signals, Keyphasor references, and vibration sensor inputs in continuous machinery protection applications. The module processes accelerometer and velocity sensor data, applies user-defined vibration thresholds, and delivers alarm/shutdown relay outputs and 4-20 mA analog signals to downstream DCS/PLC systems.
## Technical Specifications
**Electrical**
• Operating Voltage: 24V DC
• Current Rating: 1 A
• Relay Switching Capacity: 10 A @ 250V AC
• Input Signal Type: Digital
• Output Signal Type: Relay
• Keyphasor Input Range: −24 VDC to 0 VDC (proximity probe)
• Operating Temperature: −40°C to +85°C
**Physical & Functional**
• Module Type: XDCR I/O and Record Terminals / Dual Epoxy Relays Module
• Relay Configuration: Dual epoxy relays
## Key Features
• Processes Keyphasor signals for phase and speed reference in rotating machinery
• Accepts accelerometer or velocity sensor inputs for real-time vibration monitoring
• Supports FFT spectrum analysis to identify fault characteristic frequencies (imbalance, misalignment, bearing wear)
• User-configurable vibration alarm and danger thresholds with relay interlock triggering
• Converts vibration signals to 4-20 mA analog output for DCS/PLC integration
• Monitors shaft axial position for early thrust bearing failure detection via LVDT signals
• Supports casing growth measurement on expansion monitor applications
• Dual epoxy relays rated for industrial duty cycles
## Typical Applications
• Machinery condition monitoring and protection in petroleum and process industries
• Vibration-based fault detection and alarm generation
• Thrust bearing axial position monitoring
• Casing expansion monitoring on large rotating equipment
• API 670–compliant machinery protection systems
## Compatibility & Integration
The 81545-01 integrates with Bently Nevada 3300 Series monitors (3300/20, 3300/25, 3300/45, 3300/48) and is also compatible with 3300 and 3500 Series Monitoring Systems. It functions within modular racks that include system monitors, power supplies, and additional monitor modules to create scalable, application-specific machinery protection architectures.
