Product Overview
The BENTLY 133442-01 is a dual-channel Tachometer Input/Output Module with Internal Terminations, purpose-built for the Bently Nevada 3500/50M Tachometer Monitor within the 3500 Series Machinery Protection System. As a rear-mounted interface module, the BENTLY 133442-01 serves as the critical bridge between field-mounted speed transducers and the 3500 rack’s monitoring architecture, processing pulse signals from proximity probes or magnetic pickups to deliver precise shaft rotational speed, rotor acceleration, and rotation direction data.
Unlike standard modules that demand external termination blocks, the BENTLY 133442-01 features integrated internal terminations that allow field wiring to connect directly to the rear of the rack, substantially simplifying cabinet layouts and reducing installation complexity. This design eliminates the need for additional junction hardware, lowering overall system costs and footprint while streamlining maintenance access.
Engineered for demanding industrial environments, the BENTLY 133442-01 operates reliably across a wide temperature range and supports both standard and Triple Modular Redundant configurations through configurable input impedance options. Its high-frequency signal processing capabilities enable accurate speed measurement across a 0–99,999 RPM range, making it an essential component for turbine, compressor, and large motor protection schemes where rotational speed integrity is paramount.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | BENTLY 133442-01 |
| Manufacturer | Bently Nevada (Baker Hughes) |
| Product Type | Tachometer I/O Module with Internal Terminations |
| Series | 3500 Machinery Protection System |
| Number of Channels | 2 Independent Channels |
| Input Signal Range | +10.0 V to -24.0 V DC |
| Input Impedance | 20 kΩ (Standard); 40 kΩ (TMR) |
| Maximum Input Frequency | 20 kHz |
| Speed Range | 0–99,999 RPM |
| Power Consumption | 5.8 W (Typical) |
| Operating Temperature | -30°C to +65°C (-22°F to +150°F) |
| Dimensions | 241.3 mm × 24.4 mm × 163.1 mm |
| Weight | Approximately 0.20 kg (0.44 lbs) |
| Transducer Power Supply | -24 Vdc, 40 mA per channel |
| Compliance | API 670, CE EMC, UL Class I Div 2 |
Main Features and Advantages
Dual-Channel Measurement Architecture: The BENTLY 133442-01 consolidates two independent speed measurement circuits into a single rack slot, enabling simultaneous monitoring of two separate points on one machine or across two different assets. This eliminates the need for multiple single-channel cards, preserving valuable rack space and reducing hardware costs for redundant speed monitoring configurations.
Integrated Internal Terminations: The defining feature of the BENTLY 133442-01 is its integrated termination design. Field wiring connects directly to the module’s rear-mounted screw terminals, bypassing the external terminal blocks required by legacy 3500/50 units. This reduces cabinet complexity, cuts installation time, and simplifies ongoing maintenance—technicians can rework transducer cabling or address damaged terminals without extracting the front measurement card from the rack.
High-Precision Signal Processing: The BENTLY 133442-01 delivers exceptional measurement accuracy across its full operating range, with ±0.1 RPM resolution below 100 RPM and ±0.01% accuracy above 10,000 RPM. Automatic and manual threshold adjustments, combined with programmable hysteresis from 0.2 V to 2.5 V, ensure reliable signal acquisition even in electrically noisy industrial environments.
Keyphasor Signal Distribution: Beyond basic speed measurement, the BENTLY 133442-01 can provide conditioned Keyphasor signals to the 3500 rack backplane, supplying reference pulses for synchronous vibration tracking and phase analysis across adjacent monitoring modules. This integrated capability often eliminates the need for a dedicated Keyphasor module in many system configurations.
