Bently Nevada 133442-01 3500/50M I/O Module with Internal Terminations

Product Overview

The Bently Nevada 133442-01 is a dual-channel Tachometer Input/Output (I/O) module designed for the 3500 Series Machinery Protection System. This module serves as the primary physical interface for field wiring, specifically engineered to operate with 3500/50 and 3500/50M Tachometer Main Modules. It processes high-frequency pulse inputs from proximity probes or passive magnetic pickups to facilitate precise measurements of rotational speed, rotor acceleration, and reverse rotation.

As an internal termination variant, the 133442-01 features integrated screw terminal blocks directly on the module body, optimizing it for high-density cabinet installations where space is a priority. This hardware configuration is widely deployed in power generation, petrochemical, and gas compression facilities for continuous machinery monitoring and critical overspeed protection.

Technical Specifications

Ordering Information

When procuring spare parts, ensure the part number matches the specific rack configuration to avoid hardware/software mismatch errors.

• Part Number: 133442-01

• Component Description: 3500/50M Tachometer I/O Module with Internal Terminations (Internal Barrier Type)

• Associated Main Module: 3500/50-01-XX or 3500/50M-01-XX

• Terminal Type: Fixed screw terminal blocks

Engineering & Field Wiring Guide

Wiring and Shielding Requirements

• Cable Selection: Use twisted, shielded pair cabling (18 AWG to 22 AWG) for all transducer connections to mitigate electromagnetic interference.

• Shield Grounding: Connect shields to the designated instrument ground terminal on the 3500 rack chassis at one end only. Do not ground at the field transducer to prevent ground loops.

• Signal Separation: Maintain a minimum distance of 300 mm (12 inches) between speed sensor cables and high-voltage AC power lines.

Installation and Hot-Swap Precautions

• Rack Alignment: The 133442-01 must be installed in the rear slot corresponding to the front-mounted 3500/50M main processor.

• Bypass Protocol: Prior to module extraction or insertion, bypass all associated machinery trip relays to prevent accidental turbine or compressor trips.

• Torque Limits: Tighten terminal block screws to a maximum of 0.56 N·m (5 in·lb) to protect the internal PCB traces.

Frequently Asked Questions

• Is the 133442-01 compatible with older 3500/50 modules?

  Yes, it is fully backwards compatible with standard 3500/50 and upgraded 3500/50M modules, provided the rack configuration software matches the hardware variant.

• What is the difference between this and the External Termination (ET) version?

  The 133442-01 features built-in terminal blocks. The ET version requires a multi-pin cable to connect to a remote DIN-rail terminal block.

• What are the risks of exceeding the input signal range?

  While internal clipping circuits limit voltages, sustained overvoltage outside the +10V to -24V range can degrade the internal barrier circuitry and cause channel faults.