Product Overview

The Bently Nevada 3500/42M​ Four-Channel Proximitor / Seismic Monitor is a half-height (1-slot) monitor module that installs in a Bently Nevada 3500 Series Machinery Protection System rack (3500/05). It is the direct functional product behind the custom-ordered reference 2401-30056 KSL Monitors, which typically denotes a 3500/42M configured for radial vibration (two eddy-current probe channels), axial thrust position (one channel differential), and a Keyphasor® / tach reference (one channel) — a common KSL (Key Shaft Lock / Keyphasor Shaft Location) package for large rotating equipment. The Bently Nevada 3500/42M​ accepts inputs from Bently Nevada eddy-current proximity transducers (3300-series 5 mm / 8 mm probes with matching extension cables and Proximitor® sensors), seismic velocity sensors (330500 / 330525), and accelerometers (330450 / 330455), conditioning the signals for gap voltage, static position, dynamic vibration (peak-peak or true RMS), and shaft rotational speed/phase.Each of the four independently configurable channels on the Bently Nevada 3500/42M​ can be assigned one of several measurement types: Radial Vibration (1X / 2X filtered or unfiltered), Thrust Position (single or differential), Eccentricity (slow roll), Differential Expansion, Casing Acceleration, Casing Velocity, or Keyphasor (tach). The module performs Alert and Danger alarm evaluation per API 670, drives the 3500/32 (or integral) relay modules for trip logic, and makes conditioned data available to the 3500/22M Transient Data Interface (TDI) or 3500/94 Communication Gateway for trending and diagnostics via System 1® software. The Bently Nevada 3500/42M​ (custom config 2401-30056) is fully backwards-compatible with the 3500 backplane, supports triple modular redundant (TMR) voting when three monitors are ganged, and is the recommended replacement for the legacy 3500/40M in new installations. Its rugged design, intrinsic safety barriers (when used with IS Proximitor sensors and appropriate 3500/06 Isolator), and extensive certification make the Bently Nevada 3500/42M​ the industry benchmark for turbine, compressor, and large-motor protection worldwide.

Technical Specifications

Product Model | 3500/42M (custom config reference 2401-30056 KSL typical)Manufacturer | Bently Nevada / Baker HughesProduct Type | 3500 Series 4-Channel Proximitor / Seismic / Dynamic Monitor ModuleCompatible Rack | 3500/05 (Standard, Mini, or Extended) Machinery Protection System RackNumber of Input Channels | 4 (independently configurable)Accepted Input Types | Eddy-Current Proximity Probe (3300 5 mm / 8 mm with 3300/xx Proximitor®); Seismic Vel Transducer (330500, 330525); Accelerometer (330450, 330455); Keyphasor (3300 XL 8 mm or magnetic pickup)Proximitor Input Impedance | 7.5 kΩ (typical)Proximitor Gap Voltage Range | 0.0 … 24.0 V DC (displayed)Seismic / Accel Input Range | ±25 V pk (seismic), ±5 V pk (accel) per channelMeasurement Types per Channel | Radial Vibration, Radial (1X/2X Filtered), Thrust Position (Single / Diff), Differential Expansion, Casing Accel/Vel, Eccentricity (Slow Roll), Keyphasor (Tach), Shaft Relative / AbsoluteAlarm Setpoints | Individually programmable Alert & Danger per channel; OK / Alert / Danger status per API 670Outputs / Interfaces | To 3500 backplane for relay modules (Alert/Danger); to TDI (3500/22M) for waveform & static data; to 3500/94 for Ethernet commsPower Consumption (typ) | 5.2 W (from 3500 backplane +5 V / +24 V)Operating Temperature | -30 … +65 °C (-22 … +149 °F)Storage Temperature | -40 … +85 °CHumidity | 0–95 % RH non-condensingDimensions (H × W × D) | Half-height 3500 module: 128.6 mm × 30.7 mm × 228.6 mm (5.06″ × 1.21″ × 9.0″)Weight | Approx. 0.45 kg (1.0 lb)Isolation | Input to Backplane: 500 V DC; Channel-to-Channel: internally referenced to common I/O groundCertifications | CSA/NRTL, CE, ATEX/IECEx (with IS barrier config), ABS (Marine Type Approval), API 670 CompliantFirmware / Config Software | 3500 Rack Configuration Software (RCS); monitored via System 1® with 3500/22M TDI