Product Overview

The Bently Nevada 138700-01 is a high-precision input/output interface engineered for the 3500/42 Proximitor Monitor system. This module is specifically tasked with facilitating "Shaft Absolute" measurements, a critical diagnostic parameter that combines shaft vibration and casing vibration signals to determine the true motion of the shaft in space. By providing a ruggedized termination point for proximity probes and seismic transducers, the 138700-01 allows the 3500 rack to calculate the absolute displacement of a rotating rotor relative to a free-space reference. This level of monitoring is vital for large-scale turbomachinery where high casing-to-shaft vibration ratios could otherwise mask dangerous mechanical conditions.

Comprehensive Hardware Parameters and Physical Specifications

The 138700-01 is built to industrial standards to ensure low-latency signal routing and long-term durability in high-stress environments.

• Module Function: Shaft Absolute I/O Interface

• Compatible Primary Monitor: Bently Nevada 3500/42 series

• Input Signal Support: Integrated proximity and seismic sensor processing

• Mounting Requirement: Occupies one full-height rear slot in the 3500 chassis

• Terminal Type: High-density screw terminal blocks for secure field wiring

• Internal Isolation: Enhanced protection against ground loops and EMI

• Unit Weight: 0.38 kg

• Standard Dimensions: 24.13 cm x 2.44 cm x 9.91 cm

• Manufacturing Origin: USA (United States)

• Standard Warranty: 12 Months

Industrial Usage and System Deployment

This I/O module is a prerequisite for comprehensive machinery protection in heavy industrial facilities, including:

• Steam and Gas Turbine Monitoring: Tracking the absolute shaft motion of large turbine trains where casing vibration is significant.

• Hydroelectric Generators: Providing accurate rotor position data in environments prone to structural resonance and low-frequency oscillations.

• Petrochemical Compression Trains: Linking critical shaft vibration data to the 3500 rack's alarm and trip logic to prevent catastrophic bearing failure.

• Predictive Maintenance Data Centers: Serving as the high-fidelity signal source for transient data acquisition and specialized machinery diagnostic software.

FAQ

Q: What exactly does "Shaft Absolute" monitoring mean in the context of the 138700-01?

A: Shaft Absolute monitoring measures the shaft's vibration relative to a fixed point in space by combining signals from a proximity probe (shaft relative to casing) and a velocity sensor (casing relative to space). The 138700-01 provides the inputs necessary to perform this calculation.

Q: Can this I/O module be used with the 3500/42M (Internal Termination) monitor?

A: The 138700-01 is designed for External Termination configurations. You must ensure your 3500/42 monitor is compatible with external I/O modules before installation.

Q: Is the terminal block included with the 138700-01?

A: Typically, the I/O module includes the terminal blocks for field wiring. However, for some redundant configurations, separate terminal headers might be required.

Q: Does this module require periodic calibration?

A: The 138700-01 is a passive interface for signal routing; however, the 3500/42 main monitor it connects to must be calibrated according to Bently Nevada's recommended machinery protection schedule.

Q: Is the 138700-01 suitable for hazardous area installations?

A: Yes, when installed within a 3500 rack that utilizes appropriate intrinsic safety (IS) barriers or galvanic isolators, this module can be used to monitor equipment located in classified hazardous zones.