1. General Information

• Manufacturer: Bently Nevada (Baker Hughes)

• Model Number: 3500/40M

• Spare Part Number: 176449-01

• Product Name: Proximitor Monitor Module

• Series: 3500 Machinery Protection System

• Module Type: Full-height four-channel displacement monitor

• Application: Online monitoring for shaft radial vibration, thrust position, eccentricity and differential expansion; dedicated for eddy-current proximity probes, widely used in steam turbine, compressor and high-speed rotating equipment.

• Matching I/O Board: 125680-01 (Internal termination board)

• Compliance: API 670

2. Functional Description

• Channel Quantity: 4 independent programmable input channels

• Monitoring Function: Radial Vibration, Thrust Position, Eccentricity, Differential Expansion, REBAM

• Channel Configuration: Configured in pairs (Ch1-2 / Ch3-4), maximum 2 types of measurement per module

• Alarm Logic: Programmable Alert & Danger setpoints per channel

• Signal Type: Only for eddy-current proximity probe (no seismic sensor)

3. Electrical Specifications

• Backplane Power: +5 VDC from rack backplane

• Power Consumption: 10.5 W typical

• Sensor Power: -24 VDC for proximity transducer

• Input Amplitude Range: ±500 mV Peak

• Frequency Response: 0.5 Hz ~ 10 kHz

• Analog Output: 4-channel isolated 4-20mA output, Max 600 Ω load

• Isolation Voltage: 1500 VAC channel-to-system isolation

4. Environmental Specifications

• Operating Temperature: -30 °C ~ +65 °C (-22 °F ~ +149 °F)

• Storage Temperature: -40 °C ~ +85 °C (-40 °F ~ +185 °F)

• Relative Humidity: 5% ~ 95% (Non-condensing)

• Anti-vibration: Compliant with API 670 industrial vibration standard

5. Mechanical Specifications

• Structure: Full-height single slot module

• Dimensions (H × W × D): 241.3 × 24.4 × 241.8 mm

• Weight: Approximately 0.91 kg

• Mounting: 3500 standard rack slot installation, hot-swap capable

6. Compatible Devices

• Matching I/O Board: 125680-01 (Internal termination board)

• Sensor Type: Eddy-current proximity probe series

• System Rack: All standard 3500 series racks

7. Key Features

• Professional displacement monitoring module for proximity probes

• Multi-function programmable measurement for various shaft parameters

• High stability and high precision for slow displacement signal

• Internal terminal design for simple and reliable wiring

• Complete API 670 compliance for critical machinery protection

8. Critical Difference (40M VS 42M)

• 3500/40M: Pure displacement card, only proximity probe, shaft position/eccentricity, no seismic vibration.

• 3500/42M: Dual-purpose vibration card, support proximity + velocity/accelerometer, casing vibration.