Description
1. Product Title
Bently Nevada 3500/65 (PN: 145988-02) – 16-Channel Temperature Monitor
2. Product Overview
The Bently Nevada 3500/65 (Part Number 145988-02) is a high-density, 16-channel temperature monitoring module designed for the Bently Nevada 3500 Machinery Protection System. This module provides continuous, real-time monitoring of critical equipment temperatures by accepting inputs from Resistance Temperature Detectors (RTDs) and Thermocouples (TCs). Widely used in power generation, oil & gas, and heavy industrial applications, the 3500/65 ensures the safety of turbines, compressors, pumps, and motors by detecting overheating conditions that could lead to lubrication failure, thermal distortion, or fire. The specific part number 145988-02 indicates a configuration optimized for mixed sensor inputs, offering flexible channel-by-channel programming to accommodate diverse temperature sensing requirements within a single rack slot. It integrates seamlessly with the 3500 framework to provide alarm annunciation, relay trip outputs, and data communication to host control systems.
3. Technical Specifications
- Brand: Bently Nevada (a Baker Hughes business)
- Model: 3500/65
- Part Number: 145988-02
- Function: 16-Channel Temperature Monitor
- Input Channels: 16 Independent Inputs
- Supported Sensor Types:
- RTDs: 2-wire, 3-wire, or 4-wire configurations (e.g., Pt100, Pt1000, Ni120).
- Thermocouples: Types J, K, T, E, R, S, B, N, C.
- Resistive Voltage Inputs: Optional support for specific resistive sensors.
- Channel Configuration: Each channel can be individually configured for sensor type, scaling, and alarm limits via software.
- Accuracy:
- RTD: Typically ±0.5°C or better depending on sensor class.
- Thermocouple: Typically ±1.0°C or ±0.5% of reading.
- Alarm Capabilities:
- Two independent alarm setpoints per channel (Alert and Danger).
- Configurable alarm delays (On-delay/Off-delay) to prevent nuisance tripping during transients.
- Latching or non-latching alarm modes.
- Relay Outputs:
- Drives system-level relays via the 3500 backplane (typically controlled by the 3500/15 Power Supply or Relay Driver modules based on logic summation).
- Supports “Voted” logic (e.g., 2-out-of-3 voting) when multiple temperature monitors are used for critical trips.
- Communication:
- Backplane communication to the 3500/22 or 3500/22M Transient Data Interface for Ethernet connectivity to System 1 or DCS.
- Supports Modbus RTU/TCP via the gateway.
- Power Consumption: Approx. 6.5 Watts (powered via 3500 backplane).
- Operating Temperature: -20°C to +70°C (-4°F to +158°F)
- Mounting: Installs in any available slot in the 3500 rack (excluding power supply slots).
- Certifications: CE, CSA/NRTL/C, ATEX/IECEx (when installed in certified racks), SIL 2 capable (as part of a protected system).
4. Key Features & Benefits
- High Channel Density: The 3500/65 packs 16 channels into a single module, significantly reducing rack space and wiring complexity compared to discrete temperature switches or lower-density monitors.
- Flexible Sensor Support: With the ability to mix RTDs and Thermocouples on the same card, the 145988-02 simplifies inventory management and allows for tailored monitoring strategies for different parts of a machine (e.g., bearing RTDs and exhaust TCs on a turbine).
- Advanced Alarm Logic: Features sophisticated alarm processing including delay timers and hysteresis, which helps distinguish between genuine fault conditions and temporary process upsets, thereby preventing unnecessary plant shutdowns.
- Seamless Integration: As a native component of the Bently Nevada 3500 system, it shares a common backplane and communication architecture with vibration and position monitors, providing a unified view of machine health in the System 1 software.
- Hot-Swappable: Can be replaced without powering down the entire rack (though protection for those specific channels is temporarily lost), facilitating faster maintenance and reduced downtime.
5. Application Scenarios
- Gas Turbine Exhaust Monitoring: Deployed to monitor dozens of exhaust thermocouples in a gas turbine, detecting hot spots or combustion imbalances that could indicate nozzle damage or fuel distribution issues.
- Large Motor Bearing Protection: Used on critical high-voltage motors to track stator winding and bearing temperatures via RTDs, triggering alarms before insulation breakdown or bearing seizure occurs.
- Compressor Lube Oil Systems: Integrated into compressor skids to monitor oil cooler outlet temperatures and bearing return oil temperatures, ensuring the lubrication system operates within safe thermal limits to maintain oil viscosity and film strength.
6. Frequently Asked Questions (FAQ)
- Q: What is the difference between the 3500/65 and the 3500/61?
- A: The 3500/65 (PN 145988-02) is a 16-channel temperature monitor, whereas the 3500/61 is typically a 16-channel thermocouple only monitor or an older revision. The 3500/65 offers broader support for both RTDs and Thermocouples with more advanced configuration options and diagnostics. Always verify the specific part number suffix for exact input capabilities.
- Q: Can I mix RTD and Thermocouple inputs on the same 145988-02 module?
- A: Yes, one of the key features of the 3500/65 is that each of the 16 channels can be independently configured. You can have Channels 1-8 wired to Pt100 RTDs and Channels 9-16 wired to Type-K Thermocouples, provided the wiring terminals and software configuration match the sensor types.
- Q: Does the 3500/65 provide direct relay outputs on the front panel?
- A: No, the 3500/65 does not have discrete relay outputs on the module itself. Instead, it communicates alarm and trip conditions over the 3500 backplane to dedicated Relay Output modules (like the 3500/32 or 3500/33) or the Power Supply frame relays, which then physically switch the external circuits. This architecture allows for flexible voting logic across multiple input types.
BENTLY 3500/20 125744-02 Bently Nevada 3500/15 133292-01 Bently Nevada 3500/15 127610-01
- A: No, the 3500/65 does not have discrete relay outputs on the module itself. Instead, it communicates alarm and trip conditions over the 3500 backplane to dedicated Relay Output modules (like the 3500/32 or 3500/33) or the Power Supply frame relays, which then physically switch the external circuits. This architecture allows for flexible voting logic across multiple input types.
