Bently Nevada 3300/50-02-01-00-00 TACHOMETER MODULE

Note: This module must not be used as part of an overspeed protection system. It is intended only for annunciator and data recording applications.

• Monitoring Range:

  Zero-speed monitoring for < 100 rpm;

  Compatible with speed monitoring from 1 to 99,999 rpm;

  Rotor acceleration / deceleration: -9,999 to 9,999 rpm/min.
• Input Specifications:

  Supports Bently Nevada 3300, 7200, and 3000 Series proximity probes and magnetic pickups (magnetic pickups not recommended for zero-speed monitoring);

  Dual sensor inputs;

  Input impedance: 10 kΩ.
• Relay Configuration:

  Epoxy-sealed alarm relays (Option 01 for Segment B);

  Provides 2 alarm relay drive signals + 1 OK relay drive signal;

  Alarms configurable for latching / non-latching operation.
• Output Specifications:

  Programmable recorder outputs:

  4–20 mA, 0 to -10 Vdc, or 1–5 Vdc;

  Voltage output impedance: 100 Ω (minimum load 10 kΩ);

  4–20 mA output load impedance: 0–600 Ω.
• Accuracy:

  Recorder output:

  ±1.8% of signal + ±0.09 mA offset for 4–20 mA;

  ±2.2% of signal + ±10 mV offset for 1–5 Vdc;

  ±2.1% of signal + ±15 mV offset for 0 to -10 Vdc;

  Speed display accuracy: ±1 rpm;

  Zero-speed monitoring: manual threshold mode (factory default);

  Threshold adjustable: 0 to -18 Vdc;

  Hysteresis adjustable: 0.2–2.0 V.
• Power & Physical Characteristics:

  Nominal power consumption: 2.5 W;

  Weight: 1 kg (2.2 lbs.);

  Occupies 1 rack slot (cannot be installed in slots 1/2, reserved for power / system monitoring).
• Environmental Ratings:

  Operating temperature: 0–65°C (32–150°F);

  Storage temperature: -40–85°C (-40–185°F);

  Relative humidity: ≤95% non-condensing.
• LED Indicators:

  Green OK LEDs for Channels A / B;

  Two red alarm LEDs;

  Red bypass LED;

  5 Hz flashing OK LED indicates memory fault code;

  Flashing alarm LED indicates first-out alarm.
• Alarm Delay:

  Zero-speed alarm requires 3 valid input triggers;

  If no trigger detected, zero-speed alarm declared after max. 1 minute;

  1 valid pulse required after power-up to enable alarm detection.
• Buffer Output:

  Front-panel BNC connector per sensor channel;

  Short-circuit protected;

  Output impedance: 100 Ω.

• 

2. Core Functions & Design Features

• Dedicated Zero-Speed Monitoring:

  As a zero-speed tachometer (Option 02 for Segment A), optimized for zero-speed conditions below 100 rpm. Zero-speed alarm functions as underspeed alarm, with digitally adjustable threshold from 0–100 rpm. Parameters stored in non-volatile memory.
• Dual Sensor Redundant Input:

  Supports any combination of two sensors with built-in voting logic. Maintains valid monitoring during single-sensor failure, reducing false alarms.
• Flexible Output & Programming:

  Multi-range recorder outputs for proportional speed / acceleration signals. Field-configurable jumpers for sensor type, events per revolution (numerator / denominator 1–255, ratio ≥ 0.1), alarm reset mode, and other parameters.
• Industrial-Grade Reliability:

  Epoxy-sealed relays for industrial environments;

  Front-panel LCD with dual 5-digit display for speed / acceleration and probe gap voltage;

  All alarm setpoints adjusted via tamper switch + system monitor panel keys to prevent unauthorized operation.
• Safety & Compliance:

  Complies with EMC (Certification 158710) and Low Voltage Directive (Certification 135300);

  Supports CSA/NRTL/C Class I Div 2 hazardous area certification options;

  No internal safety barrier (Option 00 for Segment D);

  External safety barriers can be added for explosion-proof applications.

3. Applications & Operating Notes

Applications

Key Limitations

• Not for standalone speed control or overspeed protection systems, or as a component in such systems;
• Lacks protection redundancy and response speed required for overspeed protection;
• Analog outputs for data recording / charting only;
• Speed alarms for status indication only.

Sensor Selection

• Magnetic pickups prohibited for zero-speed monitoring;
• Bently Nevada 3300 Series proximity probes recommended;
• Both sensors must be programmed for the same number of events per revolution.

Installation Requirements

• Do not install in rack slots 1/2;
• For ATEX-certified configurations, install monitor rack in weatherproof enclosure;
• Single-point grounding required;

• Proper connection of shielded cables mandatory.

• 

4. Typical Bently Nevada 3300 Series Monitoring Modules

1. 3300/50-01-01-00-00
   Dual-setpoint tachometer module, epoxy-sealed relays, no certification / no safety barrier.
2. 3300/50-03-02-01-00
   Rotor acceleration tachometer module, sealed relays, CSA/NRTL/C certified.
3. 3300/40
   Shaft vibration monitoring module, supports 3300 Series probes, single / dual channel available.
4. 3300/53
   Electronic overspeed detection module, dedicated to overspeed protection, replaces 3300/50 in protection applications.
5. 3300/60
   Shaft position monitoring module for radial / axial position measurement.
6. 3300/70
   Temperature monitoring module, supports thermocouples / RTDs, integrates into 3300 racks.
7. 3300/50-02-00-02-02
   Zero-speed tachometer module, no relays, ATEX self-certified, built-in safety barrier.
8. 3300/20
   General-purpose vibration monitoring module, supports piezoelectric accelerometers.
9. 3300/90
   System monitor module, core control module for 3300 racks, for slots 1/2.
10. 3300/50-01-02-00-01
    Dual-setpoint tachometer module, sealed relays, no certification, external safety barrier.