Bently Nevada 136711-02 3500/61 RTD/TC I/O Module

Description

The Bently Nevada 136711-02 is a specialized RTD/TC I/O Module with Internal Barriers and Internal Terminations developed for the 3500/61 16-Channel Temperature Monitor within the 3500 Series Machinery Protection System. This hardware component serves as the physical interface layer that collects multi-channel temperature signals from field-located transducers. This specific non-isolated variant is engineered with integrated safety barriers, allowing users to configure the termination paths to accept either thermocouple (TC) or resistance temperature detector (RTD) inputs, as well as a flexible combination of both sensor categories simultaneously within the same rack subsystem.

Field programming and configuration of channel types are handled through the 3500 Rack Configuration Software, removing any requirements for physical hardware modifications or field calibration procedures. The module conditions the raw millivolt signals from thermocouples and resistance variances from 3-wire or 4-wire RTDs, feeding structured digital temperature values directly into the main front processor card via the internal backplane bus. Its onboard intrinsic safety design provides a high degree of integration by combining terminal blocks and hazardous area containment barriers into a single space-saving footprint, making the 3500/61 subsystem ideal for multi-point thermal surveillance of bearings, stator windings, and exhaust paths on heavy rotating assets.

Features

• Houses physical internal termination blocks paired with integrated safety barriers for hazardous field environments.
• Non-isolated universal channel paths support individual configuration for TCs, 3-wire RTDs, or 4-wire RTDs.
• Eliminates the need for manual component calibration through full integration with the 3500 Rack Configuration Software.
• Includes dedicated high-precision current source networks to satisfy multi-lead RTD measuring circuits.
• Structural design optimizes rack footprint by consolidating external terminal boxes and separate intrinsic safety hardware into one rear slot.

Applications

• Multi-channel motor and generator stator winding thermal monitoring.
• Gas turbine exhaust gas temperature (EGT) profile tracking and distribution mapping.
• Industrial bearing temperature monitoring on high-speed pumps, fans, and gearboxes.
• Balance-of-plant auxiliary machinery protection across chemical and petrochemical facilities.

Ordering Information

• 136711-02: RTD/TC I/O Module with Internal Barriers and Internal Terminations (Non-Isolated)

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Chassis Alignment: Install the 136711-02 module directly from the rear side of the 3500 monitoring chassis. It must align perfectly into the slot corresponding to the front-mounted 3500/61 main processor card.
• Sensor Type Matching: Verify through configuration utility software that each channel configuration (thermocouple versus 3-wire or 4-wire RTD) exactly matches the field wire layout connected to the terminal strip.
• Lead Wire Uniformity: For all 3-wire and 4-wire RTD configurations, employ copper lead wires of uniform gauge and length to guarantee precise lead-resistance compensation.
• Shield Grounding Control: Run all external field sensor lines through twisted, shielded wire pairs. Land the shields at the designated instrumentation ground terminal provided on the module frame.
• Environmental Enforcement: Ensure the cabinet installation maintains clean, unobstructed ventilation paths so that the active operating ambient temperature around the internal barrier housing does not exceed 65 degC.

FAQ

What is the function of the 136711-02 component?

It acts as the rear terminal and intrinsic safety interface module that routes field RTD and thermocouple signals into a 3500/61 monitor slot.

What does the designation non-isolated mean for this module?

It indicates that the channels share a common ground reference point, although they remain protected via built-in internal safety barriers.

Can I mix thermocouples and RTDs on the same I/O card?

Yes, the non-isolated channel paths can be customized individually via software to accept a mixed combination of TCs and RTDs.

What specific type of RTD is recommended for standard engineering installations?

Platinum RTDs featuring an alpha value of 0.00385 are the industrial standard and are highly recommended for optimal precision.

Is manual field calibration required after replacing this hardware?

No manual field calibration is needed because all channel parameter scaling is managed automatically through system configuration software.

What constant current value is provided for RTD sensors by this module?

The integrated current source network delivers 925 +/- 15 uA at an environmental reference of 25 degC per transducer pathway.

How many internal current supplies are engaged when a 4-wire RTD is connected?

The module configuration activates a single current supply line for a 4-wire RTD circuit and two separate supplies for a 3-wire RTD circuit.

What is the defined operating temperature limitation for this module version?

The module is specified to perform reliably in a continuous ambient temperature environment ranging from 0 degC to +65 degC.

What are the exact physical dimensions of this rear-mount component?

The card measures 241.3 mm in height, 24.4 mm in width, and 163.1 mm in depth.

Does this component contain the primary digital processor card?

No, this part number represents the rear-insert I/O termination assembly with built-in barriers; the front processor module is supplied separately.