Bently Nevada 3500/65 145988-02 Temperature Monitor

Product Specification

3500/65 145988-02 Temperature Monitor

Brand Name:Bently Nevada

Product Name:3500/65 145988-02

Warranty:1Year

Main Features

Core Features & Advantages

• High-Density 16-Channel Design: The module’s standout feature is its ability to consolidate up to 16 channels of critical thermal data—from bearing pads to stator windings—into a single, half-height module slot. This high-density footprint saves valuable space in the control cabinet compared to legacy monitoring systems that required multiple modules for the same number of points .

• Flexible Mixed RTD/TC Configuration: The 3500/65 can be configured to accept isolated tip thermocouples, 3-wire RTDs, 4-wire RTDs, or any combination of TC and RTD inputs in the same module frame. Each channel is independently programmable via the 3500 Rack Configuration Software, allowing a single module to handle diverse temperature measurement requirements .

• Programmable Alarm Protection: Each channel supports configurable Alert and Danger setpoints adjustable from 0 to 100% of full-scale (limited by sensor range). Alarm accuracy is within 0.13% of the desired value. Configurable time delays (1–60 seconds) help prevent nuisance trips while ensuring reliable machinery protection .

• Cold Junction Compensation for Thermocouples: For thermocouple measurements, the module includes a cold junction compensation sensor accurate to ±2°C at +25°C, ensuring accurate temperature readings without external compensation hardware .

• TMR Configuration Support: In Triple Modular Redundant (TMR) configurations, temperature monitors can be installed in groups of 3 adjacent monitors. The system uses 2 types of voting to ensure accurate operation and avoid single-point failures, making it suitable for SIL-rated safety applications .

Typical Applications

The 3500/65 is widely used for continuous temperature monitoring and protection in heavy industries :

• Power Generation: Bearing temperature and stator winding monitoring on steam turbines, gas turbines, and generators

• Oil & Gas: Bearing and seal temperature monitoring on centrifugal compressors, expanders, pumps, and fans in refineries and offshore platforms

• Metallurgy & Cement: Critical component temperature monitoring on mills, rolling mills, and blowers

• Chemical & Paper: Large rotating machinery temperature monitoring in chemical processing and pulp/paper plants

Frequently Asked Questions (FAQ)

Q1: What is the difference between 145988-01 and 145988-02?
A: The 145988-02 is the current mainstream production version, while the 145988-01 is an earlier hardware version being phased out. Both share the same core 16-channel temperature monitoring functionality. When ordering, the full part number should include the termination option suffix (e.g., -01-00 for internal termination) to ensure the correct I/O configuration is supplied .

Q2: Can the 3500/65 monitor both thermocouples and RTDs simultaneously?
A: Yes. Through the 3500 Configuration Software, each of the 16 channels can be independently programmed to accept either standard RTD inputs or various thermocouple types (J, K, E, T, etc.), or a mix of both in the same module .

Q3: Is the module hot-swappable?
A: Yes, the 3500 series supports Hot Insertion/Removal. The 3500/65 module can be pulled and replaced without shutting down the entire rack. However, you should always follow your site’s specific safety procedures regarding machinery protection systems and consider bypassing associated interlocks before replacement .

Q4: What should I check if the OK LED on the front panel is off?
A: If the OK LED is off, verify the connection status of the I/O module and the back panel. If temperature readings are abnormally high, check the sensor lead resistance and verify that the sensor type setting in the configuration software is compatible with the connected sensor .

Q5: Does the module require calibration?
A: No. According to the datasheet, no calibration is required. The full-scale range for each channel is set in the field via 3500 Configuration Software. The module maintains specified accuracy without periodic field calibration .

Q6: What are the key LED indicators on the module?
A: The module features three front-panel LEDs: OK (indicates proper operation), TX/RX (indicates communication with other modules in the 3500 rack), and Bypass (indicates the monitor is in Bypass Mode) .

Q7: What is the recommended maintenance for cold junction compensation?
A: Regularly check the cold junction compensation accuracy, especially when the ambient temperature fluctuates drastically. When the Bypass LED is lit, the alarm function is disabled; monitoring mode should be restored promptly after maintenance .

Recommended Models & Related Products

The 3500/65 145988-02 is part of the 3500 Series Machinery Protection System. Below are related models and components:

Choosing the Right Model

• For high-density temperature monitoring: The 145988-02 (3500/65) is the correct choice, providing 16 channels of RTD/TC input in a single module slot .

• For lower channel count applications: The 3500/60 (4-channel) may be more cost-effective if only a few temperature points require monitoring, though it cannot be directly replaced by the /65 without reconfiguration .

• For complete system assembly: Ensure you order the matching 172109-01 I/O module along with the main card for proper field wiring connections .