Bently Nevada 3500/60 133811-01 Temperature Monitor

Product Overview

The 3500/60 (133811-01 Replaced by PN 163179-01 ) is a high-precision 6-channel temperature monitoring module designed for the Bently Nevada 3500 Machinery Protection System. This module provides critical thermal surveillance for industrial assets in power generation, oil and gas, and chemical processing plants, such as motor bearings, turbine casings, and compressor windings. By accepting direct inputs from both Resistance Temperature Detectors (RTD) and Thermocouples (TC), the 3500/60 conditions these signals and compares them against user-defined alarm setpoints. Its ability to provide instantaneous alerts and danger trips is essential for preventing catastrophic mechanical failures caused by overheating, thereby significantly reducing unplanned downtime and extending the lifecycle of mission-critical rotating machinery.

Technical Configuration

The 3500/60 architecture is engineered for maximum flexibility and industrial-grade signal integrity across various transducer types.

• Versatile Input Compatibility: Supports Type E, J, K, and T Thermocouples as well as 10 Ohm Copper, 120 Ohm Nickel, and 100 Ohm Platinum (0.00385 and 0.00392 alpha) RTDs in 3-wire or 4-wire configurations.

• Isolation Options: Available with Isolated TC I/O modules that provide 250 VDC of channel-to-channel isolation, protecting the system from external electromagnetic interference and ground loops.

• Redundancy and Voting: Fully compatible with Triple Modular Redundant (TMR) rack configurations. In TMR mode, the system utilizes specialized voting logic across three adjacent modules to ensure protection remains active even in the event of a single-point hardware failure.

• Software Defined: All channel parameters, including transducer type and full-scale range, are configured via the 3500 Rack Configuration Software, eliminating the need for manual hardware calibration.

Technical Specifications

FAQs

What is the primary difference between the 3500/60 and the 3500/61?

Both modules offer identical 6-channel monitoring functionality; however, the 3500/61 includes dedicated +4 to +20 mA recorder outputs for each channel, whereas the 3500/60 does not provide these analog outputs.

Can I mix RTD and TC inputs on the same module?

Yes. When using the RTD/TC non-isolated I/O version, the user can configure each channel independently to accept either a Thermocouple or an RTD, allowing for a hybrid input setup in a single slot.

What happens if a sensor wire breaks or short-circuits?

The module continuously monitors the transducer status. If a fault is detected (e.g., an open RTD lead), the "OK" LED will extinguish, and the channel will enter a "Not OK" state, preventing false trips while notifying operators of the maintenance requirement.

Engineering Installation and Safety Guidelines

• RTD Wiring Precision: For 3-wire RTD installations, ensure that all three lead wires have the same resistance. Variations in lead wire resistance will introduce measurement errors that the module cannot automatically compensate for. For the highest accuracy in long-distance runs, 4-wire RTD configurations are recommended.

• Cold Junction Compensation (CJC): When utilizing Thermocouples, the accuracy is dependent on the CJC sensor located on the I/O module. Ensure the I/O module is firmly seated and not exposed to direct drafts or localized heat sources within the cabinet, which could cause a temperature gradient across the terminal block.

• Hazardous Area Considerations: If the temperature sensors are located in a hazardous area, the module must be used with approved external Zener barriers. Note that using external barriers shifts the lower "OK" limit of the module to -50 deg C.

• Chassis Grounding: To maintain the specified accuracy and EMI resistance, the 3500 rack must be properly grounded. Signal cable shields should be terminated at the designated ground terminals on the I/O module to prevent noise from corrupting the high-impedance low-voltage signals from TCs and RTDs.