Bently Nevada 3500/25 125792-01 Enhanced Keyphasor Module

The Bently Nevada 3500/25 125792-01 Enhanced Keyphasor Module is an advanced rotational reference device used within the Bently Nevada 3500 Series Machinery Protection System. It is responsible for generating Keyphasor signals, which provide crucial timing information about the angular position of rotating shafts. These signals are vital for diagnosing dynamic behavior in machinery, enabling powerful diagnostic tools like orbit plots, Bode plots, and shaft centerline analysis.

This enhanced module builds on the functionality of earlier Keyphasor designs, offering dual-channel support, signal redundancy, and compatibility with both proximity probes and magnetic pickups. It ensures highly accurate signal capture even in environments with electrical noise, making it a robust solution for applications where machinery reliability and predictive maintenance are priorities.

The 125792-01 model is especially suitable for high-speed rotating equipment in industries such as power generation, oil & gas, petrochemical, and marine, where shaft phase data is a cornerstone for safe and efficient operation.

Technical Specifications

Applications

The 3500/25 125792-01 Enhanced Keyphasor Module is purpose-built for critical monitoring environments, including:

• Gas and Steam Turbines

  Delivers precise rotational reference signals essential for dynamic balancing and phase diagnostics.

• Compressors

  Used for detecting phase-related conditions like unbalance, misalignment, and gear mesh issues.

• Electric Generators

  Provides timing signals for synchronous speed verification and vibration analysis.

• Oil & Gas Operations

  Ensures high-fidelity signal capture even in high-noise upstream and downstream processing environments.

• Petrochemical Refineries

  Enables advanced diagnostics in multistage centrifugal compressors and expanders.

• Marine Propulsion Systems

  Monitors vibration and balance in high-RPM rotating components used in ships and offshore rigs.

Product Advantages

• Dual-Channel Flexibility

  Operates with one or two Keyphasor inputs—ideal for redundancy or multi-event monitoring.

• Enhanced Signal Clarity

  Integrated filtering ensures clean TTL signals even in high-interference environments.

• Broad Sensor Compatibility

  Supports industry-standard Bently Nevada proximity probes and magnetic pickups.

• Modular, Rack-Based Design

  Easily installed and replaced in 3500 Series racks with minimal system interruption.

• Diagnostic Integration

  Enables detailed dynamic plots such as Bode, polar, and orbit plots for deeper insights.

• Reliable High-Speed Operation

  Handles rotating machines operating at very high frequencies (up to 20 kHz).

• Certified for Harsh Environments

  Compliant with ATEX and CE for hazardous areas and industrial applications.

• Redundancy Ready

  Supports backup signal processing with channel-to-channel failover.

Frequently Asked Questions (FAQ)

1. What is the main function of the 3500/25 125792-01 module?

It provides time-based Keyphasor signals that act as a phase reference for vibration and rotor position diagnostics.

2. Can this module handle two independent Keyphasor signals?

Yes, it supports dual input channels which can be configured as independent or redundant.

3. What types of sensors are compatible?

It works with Bently Nevada proximity probes and magnetic pickups that produce pulse outputs.

4. Does it require an isolated I/O module?

Yes, it is typically used with isolated rear I/O cards like 126648-02 or 149369-01 to maintain signal integrity.

5. Can it be installed without shutting down the rack?

No, the rack should be powered down before module installation or replacement to ensure system integrity.

6. How does it improve machinery diagnostics?

It provides synchronized timing signals essential for advanced vibration plots like orbits and Bode diagrams.

7. Is it suitable for high-speed turbines?

Absolutely. It can process signals up to 20 kHz, suitable for high-RPM equipment.

8. How is power supplied to the module?

Power is drawn directly from the 3500 rack’s backplane—no external supply needed.

9. Is this module hot-swappable?

It is not recommended to hot-swap. Safe replacement requires power-down procedures.

10. What happens if the module fails during operation?

If redundant configuration is enabled, the backup channel takes over. Otherwise, the system will raise an alarm.