3500/50M Bently Nevada Dual‑Channel Tachometer Module new

• Brand
  Bently Nevada
• Model
  3500/50M
• Product Name
  Dual‑Channel Tachometer Module
• Place of Origin
  United States
• Customs HS Code
  8538900090
• Power Supply
  ‑24 V to +10 V
• Dimensions
  241.3 mm × 24.4 mm × 241.8 mm
• Weight
  0.82 kg
• Operating Temperature
  ‑30 °C to +65 °C
• Storage Temperature
  ‑40 °C to +85 °C
• Warranty
  12 month
• Product Status
  new and original

Bently Nevada 3500/50M Detailed Inputs:

Dual-channel transducer input: accepts up to two independent pulse signals from proximity probe (eddy-current transducer) or magnetic pickup sensors for shaft rotational speed measurementBaker Hugh...;

Proximity probe input: conditioned tachometer pulse signal from proximitor, supports low-speed tracking, zero-speed detection and reverse-rotation monitoring;

Magnetic pickup input: passive variable-amplitude AC pulse signal; note: reverse-rotation function is not available for magnetic pickup due to poor signal edge quality at low rotational speedBaker Hugh.

Signal electrical specification: input voltage range +10.0 V to -24.0 V, over-range signals are internally limited by module hardware; standard input impedance 20 kΩ;

Frequency input range: 0.017 Hz ~ 50 kHz, corresponding measuring speed range approx. 1 RPM ~ 99999 RPM; configurable trigger level for reliable pulse capturing under barring-gear low-speed conditions;

Backplane system reference input: receives rack system timing and health status signals from 3500 rack backplane for module synchronization and system-level fault diagnosis.

Bently Nevada 3500/50M Detailed Outputs:

Speed pulse output: buffered tachometer pulse signal for external speed indication and trigger reference;

Relay outputs: multi-channel form-C relay contacts for speed alarm, overspeed trip and status fault indication;

4-20 mA analog outputs: isolated analog signal proportional to measured rotational speed for DCS/PLC interface;

RS485 Modbus RTU communication output: provides speed value, alarm status, module diagnostic data for third-party host systems;

Internal system bus output to 3500 rack backplane: transmits measurement data, alarm events and health diagnostics to other 3500 series modules within the rack.

Supported Software & Host Systems:

Bently Nevada System 1 Condition Monitoring Software;

Bently Nevada 3500 Configuration Utility;

GE Digital APM Asset Performance Management platform;

Third-party DCS and PLC systems via Modbus RTU, 4-20 mA hard-wired interface;

HMI human-machine interface supporting Modbus RTU protocol.

Bently Nevada 3500/50M Commissioning and Debugging Procedure

Pre-Commissioning Verification

Carry out comprehensive pre-checks prior to power-on and configuration to eliminate mechanical, wiring and firmware incompatibility risks.

Hardware installation inspection: Confirm the 3500/50M module is fully seated and securely locked inside the designated slot of the 3500 rack. Verify rack power-supply status and firmware compatibility with the 3500/22M system monitor; the minimum supported firmware revision for 3500/22M is Rev.1.70, while the 3500/50M module firmware shall be Rev.5.30 or newer.

Sensor and cabling inspection: Use a multimeter to test continuity for proximity probes / magnetic pickups, extension cables and proximitor wiring. Inspect the speed-measuring target gear for cracks, burrs and surface contamination. Ensure all shielded signal cables adopt single-point earthing and are physically separated from high-voltage power circuits to mitigate EMI interference.

Probe gap adjustment (eddy-current proximity probe only): Supply -24 VDC power to the proximitor unit. Measure DC gap voltage and fine-tune probe clearance to achieve a nominal value of -10 VDC within the acceptable range of -9.5 VDC ~ -10.5 VDC. Secure the jam nut once gap voltage stabilises.

Commissioning tool preparation: Digital multimeter, oscilloscope, 3500-01 Configuration Software, signal generator, laptop and dedicated rack communication cable.

Static Configuration via 3500-01 Configuration Software

Establish reliable communication between the configuration laptop and 3500 rack. Open the target project and select the corresponding slot and channel assigned to the 3500/50M module.

Define channel operation mode; select one from four available configurations: - Speed monitoring with set-point alarm and speed-band alarm - Speed monitoring with set-point alarm and zero-speed detection - Speed monitoring with set-point alarm and rotor acceleration alarm - Speed monitoring with set-point alarm and reverse-rotation detection (reverse-rotation function applies exclusively to proximity probes and cannot be utilised with magnetic pickups)

Configure sensor-related parameters: - Sensor type selection: Proximity probe or magnetic pickup - Target gear tooth count (pulses per revolution), which must strictly match the physical speed-measurement gear - Trigger level: Optimise pulse trigger voltage; apply a relatively low trigger level to guarantee stable low-speed acquisition during barring-gear operation and prevent pulse loss at minimal shaft speeds - Full-scale RPM range; set acceleration limit if acceleration-alarm function is activated

Alarm and timer parameter setup: - Define Warning (Alert) and Danger trip thresholds - Configure alarm delay timer to suppress nuisance alarms triggered by transient speed fluctuations - Set zero-speed threshold, enable or disable reverse-rotation monitoring, activate peak-hold function; recorded peak speed can be manually reset upon equipment maintenance

Assign output-related parameters: - 4-20 mA analogue output: Map measured rotational-speed value and define scaling range - Buffered speed-pulse output: Configure tachometer pulse signal for external instrumentation - Relay output assignment: Allocate Form-C relay contacts for warning, danger and module-fault status - RS485 Modbus RTU settings: Modbus station address, baud rate, parity bit, register mapping for speed measurement, alarm flags and module diagnostics - Enable backplane Keyphasor output when other 3500-series modules require tachometer reference signals

Download the complete validated configuration to the 3500 rack. Perform a module reset and confirm the module OK LED remains steadily illuminated with no hardware-fault alerts.

Static Simulation Test (Shaft Stationary Condition)

All simulation tests are executed with the actual shaft kept stationary to validate measurement logic without rotating machinery hazards.

Review module diagnostic information within 3500-02 data-acquisition software; confirm no channel faults or sensor-break failures are reported.

Inject adjustable simulated pulse signals into module input terminals using a signal generator. Apply multiple known-frequency test points, then cross-check module-displayed RPM against theoretically-calculated rotational-speed values.

Verify alarm-logic performance: Input simulated signals exceeding Warning and Danger threshold values. Confirm corresponding relay contact actuation and alarm flags are correctly displayed within configuration software.

Validate 4-20 mA analogue-output performance: Measure loop current by multimeter and verify linear proportionality between real-time speed and analogue output current.

Perform Modbus RTU communication verification: Operate a Modbus master tool to read holding registers, and validate accurate transmission of speed readings, alarm status bits and module diagnostic data.

Dynamic On-Site Commissioning under Actual Shaft Rotation

Carry out full-loop field verification while the machine runs, strictly following site safety procedures for rotating equipment.

Barring-gear / low-speed operational test: Operate the shaft at low turning-gear speed and observe real-time RPM readings. Intermittent zero-reading indicates signal capture issues; readjust trigger-level setting and re-examine probe gap and target-gear surface condition.

Full-range speed validation: Increase shaft speed incrementally across the complete operating envelope. Compare 3500/50M measured values against reference readings from local mechanical tachometers or DCS system to ensure measurement deviation stays within permissible tolerance limits.

Functional feature validation: - Zero-speed detection: Stop shaft rotation and confirm zero-speed alarm status updates correctly - Reverse-rotation monitoring (if enabled): Simulate reverse-rotation condition and verify reverse-rotation alarm activation - Acceleration alarm (if enabled): Confirm proper response during rapid speed-change events - Peak-hold function: Verify maximum-speed value is captured correctly; trigger manual peak reset and confirm stored peak value is cleared

End-to-end output-interface loop test: - Relay dry contacts: Confirm warning, danger and fault status signals are accurately transmitted to ESD or PLC systems - 4-20 mA analogue loop: Confirm DCS receives scaled, accurate rotational-speed analogue values - RS485 Modbus RTU link: Verify host-system receives timely updates for speed measurement and alarm states - Buffered tachometer pulse output: Confirm external counters and local indicators receive stable pulse signals

Document all commissioning parameters for project archive, including target-gear tooth count, trigger-level value, alarm thresholds, alarm-delay setting, probe gap voltage and complete Modbus communication parameters.

Post-Commissioning Troubleshooting Reference Checklist

Module OK LED extinguished: Inspect backplane contact integrity, rack power-supply, firmware revision and successful configuration download - Zero or fluctuating RPM measurement: Check probe gap, target-gear tooth damage, cable shielding quality and trigger-level parameters; swap physical channels to differentiate between field-wiring faults and internal module hardware defects - Measurement dropout under low-speed operation: Lower pulse trigger voltage; inspect probe-gap drift, gear-surface oxidation and burr defects - Unintended nuisance-alarm activation: Extend alarm-delay timer; strengthen cable EMI-reduction measures to filter mechanical transient speed disturbances

3500/22-01-01-01
3500/22 288055-01
1900/65A
24765-02-01
3500/91-01-01-01
3500/44-02-01
TK-3E
177313-02-01
1900/65A-01-01-04-CN-00
2300/20-CN