3300/50 | Bently Nevada Condition Monitoring Tachometer

Product Overview

The Bently Nevada 3300/50 is a high-precision tachometer monitor designed for continuous machinery speed condition monitoring.
It measures shaft rotational speed, rotor acceleration, and zero-speed status within critical industrial protection systems.
Moreover, the monitor integrates directly into the proven Bently Nevada 3300 Series rack architecture.
Engineers worldwide rely on this model for stable operation in demanding turbine and compressor installations.
Therefore, it remains widely installed across power generation, petrochemical, and heavy industrial facilities.

Functional Highlights

The 3300/50 delivers accurate real-time speed measurement for rotating equipment under steady and transient conditions.
In addition, it supports zero-speed detection for permissive logic and safety interlock functions.
Although it is a single-channel monitor, it accepts two independent transducer inputs for internal voting logic.
Therefore, false speed indications caused by a single sensor failure are effectively minimized.
Moreover, proportional voltage or current outputs simplify integration with DCS and PLC monitoring systems.

Technical Data

General Characteristics

• Monitor Type: Single-channel tachometer monitor

• Compatible Rack: Bently Nevada 3300 Series

• Measurement Functions: Speed, acceleration, zero-speed indication

Input Parameters

• Supported Sensors: TTL, magnetic pickup, eddy-current proximity probes

• Number of Inputs: Two transducers with internal voting logic

• Frequency Range: 0 to 10 kHz

• Input Signal Level: 0.5 to 50 V peak-to-peak

Output Parameters

• Analog Output: Proportional voltage or current output

• Status Output: Alert relay contacts for annunciator panels

• Zero-Speed Output: Dedicated indication signal

Environmental and Physical Data

• Operating Temperature: 0 to +65 °C

• Storage Temperature: −40 to +85 °C

• Dimensions: 19.1 cm × 3.8 cm × 30.5 cm

• Weight: 1 kg

Typical Applications

The 3300/50 is commonly applied in steam and gas turbine protection systems.
For instance, it supports compressor speed monitoring in refinery and LNG process units.
Moreover, industrial pumps and large motors benefit from reliable zero-speed detection during shutdown sequences.
Therefore, the module integrates smoothly into API 670-compliant machinery protection architectures.

Reliability, Safety, and Service Considerations

The 3300/50 is intended strictly for condition monitoring and annunciation purposes.
Importantly, it is not designed for standalone speed control or overspeed protection applications.
Therefore, critical overspeed protection must use dedicated Bently Nevada overspeed detection monitors.
When installed correctly, the module provides long-term reliability with minimal maintenance requirements.

FAQ

Q: Can the Bently Nevada 3300/50 be used as an overspeed protection device?
A: No, it is intended only for monitoring and annunciation, not for protective overspeed shutdown functions.

Q: Why does the 3300/50 accept two transducer inputs if it is single-channel?
A: The dual inputs enable internal voting logic, reducing false alarms from single sensor failures.

Q: What systems can receive the speed output signal?
A: DCS, PLC, data loggers, and chart recorders can receive the proportional output signal.

Q: Is the 3300/50 suitable for retrofit installations?
A: Yes, it supports multiple sensor types, making it suitable for both retrofit and new installations.