Description

The Bently Nevada 3500/50M (Order Code 286566-02) is a 2-channel tachometer module designed for the 3500 Machinery Protection System. It is engineered to monitor shaft rotative speed, rotor acceleration, and rotor direction by processing inputs from proximity probes or magnetic pickups. The module compares these inputs against user-programmable alarm setpoints to provide critical machinery protection and predictive maintenance data.

The 3500/50M can be configured to supply conditioned Keyphasor signals to the 3500 rack backplane, eliminating the need for a separate Keyphasor module in many configurations. It also features a peak hold function to record extreme speed or reverse rotation events.

Features

• 2-channel monitoring for speed, acceleration, and direction.
• Supports proximity probes and magnetic pickups.
• Programmable alarm setpoints for speed, speed bands, and rotor acceleration.
• Zero speed notification and reverse rotation detection capabilities.
• Front-panel BNC connectors for buffered transducer signal output.
• Status LEDs (OK, TX/RX, BYPASS) for real-time diagnostic feedback.
• Configurable via 3500 Rack Configuration software.

Applications

• Offshore/FPSO pumps, compressors, and turbines.
• Refinery FCCU and H2 compressors.
• LNG liquefaction and regasification refrigeration compressors.
• Pipeline booster stations for oil and gas transmission.
• Thermal and combined cycle power plant turbines and generators.
• Hydroelectric turbine alignment and thrust monitoring.

Technical Specifications

Installation Guidelines

• Handling: Use standard ESD precautions when handling the module to prevent damage to internal circuitry.
• Mounting: The module is designed for insertion into a 3500 rack. Ensure the module is fully seated and the front-panel levers are locked.
• Termination: Requires the 288062-02 External Termination Block (ETB) for sensor wiring.
• Wiring: Connect transducers to the Euro-style connectors on the ETB. Ensure proper shielding for signal cables to minimize EMI.
• Power: Always power down the rack before inserting or removing the module.
• Software: Ensure 3500/22M firmware is version 1.70 or later and 3500/01 configuration software is version 4.20 or later.

FAQ

What is the 3500/50M?

It is a 2-channel module for the 3500 system used to monitor shaft speed, rotor acceleration, and reverse rotation, triggering alarms based on user-defined setpoints.

What sensors are compatible?

The module accepts inputs from 1 to 2 proximity transducers or magnetic pickups.

Can this be used for overspeed protection?

No. The 3500/50M is not designed for independent overspeed protection or speed control as it lacks the required protective redundancy.

What are the operational modes?

It supports Speed Monitoring (with setpoint/speed band alarms), Zero Speed Notification, Rotor Acceleration Alarming, and Reverse Rotation Notification.