Product Description

Overview

The Bently Nevada 3300/50-01-02-03-02 is a high-precision dual tachometer monitor designed for legacy 3300 machinery protection systems. It continuously measures shaft rotational speed, detects zero-speed conditions, and identifies reverse rotation. This module is essential for protecting turbines, compressors, and other critical rotating machinery by providing reliable speed monitoring and alarm functions.

Key Features

• Dual Sensor Input: Accepts signals from two Proximitor sensors or magnetic pickups with internal voting logic for improved reliability.

• Versatile Speed Functions: Supports RPM measurement, zero speed detection, and rotor acceleration monitoring.

• Peak Hold Display: Captures maximum shaft speed for overspeed analysis.

• LCD Interface: Front-panel display provides current RPM readings, bar graph alarms, and status indicators.

• Integrity Monitoring: Continuously checks transducer connections and wiring for faults.

• Hermetically-Sealed Relays: Provides robust alert and danger signaling for harsh industrial environments.

Technical Specifications

Input

• Signal Type: Pulse input from Magnetic Pickup or Proximitor sensors

• Input Frequency: Up to 20 kHz (1,200,000 CPM)

• Triggering Threshold: Manually or automatically adjustable for noise immunity

Output

• Recorder Output: 4–20 mA or 1–5 Vdc proportional to shaft speed

• Buffered Output: Front-panel coaxial connectors provide raw pulse signal for diagnostics

• Relays: Independent Alert and Danger channels, hermetically-sealed

• Contact Rating: 5A @ 120/240 Vac or 5A @ 28 Vdc

Performance

• Accuracy: ±0.01% of measured speed

• Resolution: 1 RPM (up to 9,999 RPM)

• System OK Monitoring: Detects open circuits, short circuits, or sensor failures

Environmental

• Operating Temperature: 0°C to +65°C (+32°F to +150°F)

• Storage Temperature: -40°C to +85°C (-40°F to +185°F)

• Relative Humidity: Up to 95% non-condensing

Physical

• Weight: 1 kg (2.2 lbs)

• Power Consumption: Nominal 1.5 W

• Mounting: Rack-mounted in legacy 3300 series chassis

Operational Modes

• Continuous Speed Monitoring: Tracks shaft RPM in real time.

• Zero-Speed Detection: Confirms full stop for turning gear engagement.

• Reverse Rotation Detection: Identifies backward rotation using dual sensor inputs.

Applications

Recommended for use in turbines, compressors, generators, and large rotating machinery where precise speed monitoring and overspeed detection are critical for operational safety.

FAQ

Q: Can the 3300/50 accept multiple sensor types?
A: Yes, it supports Proximitor 8mm sensors or magnetic pickups, with internal voting logic for reliability.

Q: How accurate is the speed measurement?
A: The module provides ±0.01% accuracy with 1 RPM resolution for speeds up to 9,999 RPM.

Q: Is this compatible with modern Bently Nevada systems?
A: It is designed for legacy 3300 systems. For new installations, Bently recommends the 3500/50M Tachometer Module.