June 06, 2026

Bently Nevada 1701/15 FieldMonitor Proximitor Input Monitor Product Specification

1701/15 is a dual-channel proximity monitoring module belonging to Bently Nevada FieldMonitor distributed machinery condition monitoring system, manufactured in USA and designed for plug-in installation on matched original 1701 series terminal base rack to realize decentralized signal collection nearby field rotating equipment. This module is specially matched with Bently 3300XL,7200 series eddy current proximity probe systems with standard 7.87V/mm transducer sensitivity, dedicated to real-time measurement of shaft radial vibration, rotor axial thrust position and static shaft gap displacement for critical rotating machinery. It completes onboard signal conditioning, numerical calculation, programmable alarm judgment and multi-channel signal transmission locally, widely applied on steam turbines, centrifugal compressors, large feed pumps, induced draft fans and high-speed motors in petrochemical, thermal power, metallurgy and coal chemical industries to fulfill online condition monitoring and machinery over-limit protection complying with API670 industry standard. The product has obtained ATEX, CSA and Class I Div.2 hazardous area certification to support installation inside explosive and flammable industrial field cabinets.

Description

Bently Nevada 1701/15 FieldMonitor Proximitor Input Monitor Product Specification

1. Product Overview

2. Core Functional Description

2.1 Independently Configurable Dual Measurement Channels

The module integrates two fully galvanically isolated measuring channels without internal signal crosstalk interference, each channel can be switched freely between radial vibration measurement mode and axial thrust position mode via exclusive FieldMonitor configuration software without any hardware modification. When set for radial vibration mode, it extracts alternating dynamic vibration amplitude and average static shaft gap value from proximity raw signals, supporting programmable full-scale ranges in mils or micrometers including 0~3mils pp up to 0~75mils pp and corresponding micron span options according to actual equipment operating parameters. Under thrust position mode, the unit continuously tracks continuous axial floating displacement of rotating rotor to monitor thrust bearing working status and avoid rotor-casing friction damage caused by excessive axial shifting. Two channels can run under different measurement modes simultaneously to monitor two independent mechanical parameters with a single module and optimize field cabinet wiring layout effectively.

2.2 Dual-stage Flexible Programmable Alarm Control System

Every single measuring channel is equipped with independent Alert pre-warning and Danger shutdown two-level alarm setpoints, with adjustable alarm delay ranging from 0.15s to 20s to filter instantaneous signal spike disturbance and prevent unnecessary false protection trip triggered by transient abnormal fluctuation. Alert alarm is used for early equipment fault prompting to arrange predictive maintenance plan for site operators; Danger alarm outputs passive dry contact switching signal to access equipment emergency interlock loop to cut off equipment operation when measured value exceeds safety threshold for mechanical breakdown prevention. All alarm threshold values, delay parameters and channel bypass status can be remotely modified online through upper configuration software without cutting off module working power; bypass function is enabled during sensor replacement and on-site equipment maintenance to temporarily shield open-circuit false alarm output of disconnected probes. The alarm logic supports optional latching or non-latching working mode according to user’s on-site control requirement.

2.3 Multi-path Standardized Signal Output Design

Three types of signal output are configured to realize seamless connection with mainstream industrial DCS and PLC control systems. Firstly, front panel reserves independent buffered waveform output port for each channel to export conditioned original vibration signal, facilitating on-site engineers to connect portable vibration analyzers for shaft orbit inspection and fault spectrum analysis, with built-in short-circuit protection to avoid internal circuit damage from external wiring short fault. Secondly, each channel provides isolated linear 4–20mA analog output which proportionally corresponds to full configured measurement range, directly connecting to analog input cards of control system to realize real-time data collection and long-term historical trend storage. Thirdly, all measured data, alarm state and self-diagnosis fault information are transmitted via backplane bus to system communication adapter and converted into Modbus RTU protocol over RS485 bus for remote centralized monitoring on upper computer, allowing multiple 1701 series modules cascaded on one communication bus to build distributed field monitoring network.

2.4 Continuous Full-range Built-in Self-diagnosis Function

After power-on initialization, the module starts cyclic automatic self-inspection covering internal power supply circuit, each channel input wiring loop, probe open-circuit/short-circuit abnormal state and backplane communication connection status. Front panel is fitted with three sets of LED status indicators: green RUN indicator keeps constant lighting under normal operating condition; yellow CH FAULT lamp turns on once corresponding channel detects sensor disconnection, wiring short or abnormal probe power supply; red ALARM lamp illuminates when measured parameter exceeds preset Danger protection threshold. All detected fault codes and abnormal running information are uploaded to upper monitoring platform synchronously via communication bus for quick troubleshooting and maintenance positioning to shorten equipment downtime.

3. Electrical Performance Specifications

The module acquires working power supply from matched 1701 series terminal base backplane with rated nominal input voltage of 24VDC, allowing wide input fluctuation range from 18VDC to 36VDC to adapt unstable industrial field power grid, typical full-load dual-channel total power consumption is controlled below 3.1W. It supplies standard -24VDC excitation power for matched proximity probe system calibrated at 7.87V/mm sensitivity targeting AISI4140 steel rotor material, each input channel is designed with rated input impedance matching original Bently proximity probes and factory-calibrated extension cables.

For measurement precision index, vibration full-scale measuring error is controlled within ±1%FS excluding filter influence; static gap reading precision reaches ±20mV within standard -1V~-23V working range with 1mV reading resolution. Built-in internal temperature compensation circuit limits full-temperature drift error within ±0.35% full scale across whole working temperature scope; configurable multi-order filter with adjustable cutoff frequency is available to filter power frequency interference and high-frequency clutter signals according to equipment rotating speed feature. All 4–20mA analog output circuits adopt over 500VAC channel-isolated design to block reverse voltage and surge interference transmitted from DCS side wiring faults to protect internal measuring circuit from breakdown damage.

4. Environmental and Mechanical Specifications

Certified continuous working ambient temperature range of 1701/15 module is -20℃~+70℃, spare part warehouse storage temperature covers -40℃~+85℃; applicable relative humidity is 5%~95% non-condensing environment to prevent internal circuit condensation and corrosion under high-humidity, oil mist and dusty cabinet installation environment on industrial site. Mechanical structure passes vibration verification test to continuously bear 10Hz~1800Hz vibration from adjacent running rotating equipment, suitable for installation inside compact bearing pedestal cabinets near high-temperature mechanical equipment.

Overall outer dimension of the module is 126.8mm × 21.5mm × 104.2mm with net weight around 0.26kg, adopting standardized plug-in card structure exclusively matching original 1701 series shared terminal base rack; outer shielding shell is made of aluminum alloy material to enhance anti-electromagnetic interference performance against surrounding high-power inverter and large-current power cable electromagnetic disturbance on complex industrial field.

5. System Matching and On-site Commissioning Guidance

1701/15 must be installed onto genuine matching Bently Nevada 1701 terminal base to complete power supply access and field sensor wiring connection, mismatched non-original base accessories will cause abnormal signal collection and measuring precision deviation. Only factory-calibrated original proximity probes and matched extension cables are allowed for system configuration; arbitrarily cut, spliced or third-party uncalibrated cables will change original system calibration curve and lead to measuring drift or unexpected protection misoperation. After finishing all field wiring between module and probes during commissioning, users complete channel function definition, full-scale range setup and alarm threshold programming via official FieldMonitor configuration software. When multiple modules are mounted on one same terminal base, reasonable power load calculation must be done to avoid overload damage to base internal power unit; field RS485 communication wiring requires shielded twisted-pair cable with single-point grounding construction to guarantee stable long-distance data transmission quality.

6. Quality Assurance and Warranty Regulations

Every finished 1701/15 module undergoes strict factory full-function aging test, high-low temperature cycle impact test and full-span precision calibration before delivery to verify consistent measuring performance and working stability. Standard warranty period for brand-new original genuine product is 12 months counted from formal delivery date; within valid warranty term, manufacturer provides free maintenance and component replacement service for non-artificial damaged faults occurring under specified standard installation environment and normal operating condition, while damage caused by wrong wiring, improper operation and artificial destruction is excluded from free warranty coverage.

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