BENTLY 3500/25 125792-01

Description

Detailed parameter table

BENTLY 3500/25 125792-01

Product introduction

The Bently Nevada 3500/25 125792-01 is a precision Keyphasor module, a critical component of the 3500 series machinery protection system designed to measure rotational speed and provide phase reference signals for rotating equipment. As the “timing backbone” of the monitoring system, it enables synchronized analysis of vibration, displacement, and other machinery parameters.

This module processes input signals from magnetic pickups or proximity probes, converting them into accurate speed measurements and phase markers. These phase references are essential for correlating vibration data—such as that conditioned by the 3500/40-03-00 176449-01 module—with specific rotational positions of the shaft, allowing for precise fault diagnosis (e.g., identifying the exact location of imbalance or misalignment).

The 3500/25 125792-01 integrates seamlessly with other 3500 series components via the backplane, providing synchronized data to the 3500/33 vibration monitoring module and 170180-01-00 software. Its compact design and robust performance make it indispensable for applications where precise rotational timing is critical, including turbines, compressors, and large motors in power generation, oil and gas, and manufacturing industries.

Core advantages and technical highlights

High-accuracy speed measurement: The 3500/25 125792-01 delivers exceptional speed measurement precision across a wide range (0.5 Hz to 20,000 Hz), ensuring reliable performance from slow-speed mixers to high-speed turbines. Its ability to resolve speed changes as small as 0.1 RPM allows for early detection of speed-related anomalies, such as governor instability or load fluctuations, which can precede more severe machinery issues.

Phase synchronization: By generating precise phase reference signals, the 3500/25 125792-01 enables time-aligned analysis of vibration data from the 3500/40-03-00 176449-01 and 3500/33 modules. This synchronization is critical for distinguishing between faults that manifest at specific rotational positions—for example, differentiating between a bent shaft (which creates vibration at 1x speed with consistent phase) and a loose component (which shows variable phase characteristics).

Dual-channel redundancy: Equipped with two independent Keyphasor input channels, the 3500/25 125792-01 supports redundant sensor configurations. This redundancy ensures continuous operation even if one sensor fails, a vital feature for safety-critical applications like nuclear turbine monitoring. The module automatically switches to the active sensor signal, maintaining uninterrupted phase and speed data.

Seamless system integration: The 3500/25 125792-01 shares its phase and speed data with other 3500 series modules via the backplane, enabling the 3500/40-03-00 176449-01 to time-stamp conditioned signals and the 3500/33 to perform order analysis (vibration amplitude vs. rotational order). Integration with 170180-01-00 software allows for advanced diagnostics, such as Bode plots (vibration vs. speed) and polar plots (phase vs. amplitude), which are key to balancing rotating machinery.

Typical application scenarios

In a combined-cycle power plant, the 3500/25 125792-01 is installed on a gas turbine to provide speed and phase reference for vibration analysis. It processes signals from a magnetic pickup on the turbine shaft, generating phase markers that synchronize with vibration data from 87199-01 sensors, conditioned by the 3500/40-03-00 176449-01 module. This synchronization allows engineers using 170180-01-00 software to create Bode plots, identifying resonance points as the turbine accelerates through startup. By pinpointing these critical speeds, operators can adjust startup procedures to minimize vibration stress on bearings.

Within an oil refinery’s centrifugal compressor train, the 3500/25 125792-01 monitors rotational speed and provides phase references for three compressors in series. Its dual channels connect to redundant proximity probes, ensuring continuous operation even if one probe is damaged by process vibrations. The module’s speed data, combined with pressure readings from the 3500/40-03-00 176449-01, helps operators detect surge conditions—where compressor speed drops while discharge pressure rises—triggering protective actions via the 3500/60 relay module.

In a steel mill’s rolling mill, the 3500/25 125792-01 synchronizes vibration monitoring of the main drive motor with the mill’s roll speed. By correlating phase-tagged vibration data (from the 3500/33 module) with roll speed changes, maintenance teams identify gear mesh issues in the transmission, which appear as vibration spikes at specific rotational harmonics. This targeted diagnosis reduces unplanned downtime by enabling gear replacement during scheduled maintenance.

BENTLY 3500/25 125792-01

Related model recommendations

3500/40-03-00 176449-01: Transducer signal conditioner module that works with the 3500/25 125792-01 to time-stamp vibration and temperature data.

87199-01: Eddy current sensor whose vibration signals are synchronized with phase data from the 3500/25 125792-01.

3500/33: Vibration monitoring module that uses phase references from the 3500/25 125792-01 for order analysis and fault diagnosis.

170180-01-00: Software that integrates speed and phase data from the 3500/25 125792-01 for advanced diagnostics like Bode plots.

3500/05: Rack interface module that distributes the 3500/25 125792-01’s synchronization signals across the 3500 series system.

330103-00-06-10-02-00: Magnetic pickup sensor commonly paired with the 3500/25 125792-01 for speed measurement.

3500/60: Relay module that uses speed thresholds from the 3500/25 125792-01 to trigger protective actions (e.g., overspeed shutdowns).

Installation, commissioning and maintenance instructions

Installation preparation: Before installing the 3500/25 125792-01, power off the 3500 series rack and use an anti-static wrist strap. Mount the module in a single rack slot, securing it with screws torqued to 0.6 Nm. Connect magnetic pickups or proximity probes using shielded twisted-pair cable (e.g., 149992-01), ensuring the shield is grounded at the sensor end only. Maintain a minimum 30cm separation between sensor wiring and power cables to avoid electromagnetic interference, which can corrupt speed signals.

Maintenance suggestions: Perform monthly visual inspections of the 3500/25 125792-01 to check for loose connections or corrosion on terminal blocks. Clean terminals with a dry cloth if needed. Calibrate the module annually using a signal generator to simulate known speed inputs, verifying accuracy across the 0.5 Hz to 20,000 Hz range via 170180-01-00 software. If speed readings are erratic, check for sensor misalignment, damaged cables, or debris on the target gear/keyway before replacing the module. For redundant systems, test channel switching quarterly to ensure failover functionality.

Service and guarantee commitment

The 3500/25 125792-01 is backed by a 12-month warranty covering manufacturing defects, including signal processing errors or connectivity issues. During this period, Bently Nevada provides free repair or replacement of defective units, along with technical support for integration with the 3500/40-03-00 176449-01 and other 3500 series components.

Our global service team offers 24/7 assistance for troubleshooting, with remote diagnostics available via the 3500/05 interface. Extended warranty options (up to 3 years) include annual calibration verification and priority access to software updates. Built on Bently Nevada’s legacy of precision in rotating machinery monitoring, the 3500/25 125792-01 is guaranteed to deliver reliable speed and phase data, ensuring accurate synchronization for critical machinery protection systems.