The 40M 4-channel preamplifier monitoring module is part of the Bently Nevada 3500 Machinery Protection System and is designed to process eddy current proximity sensor signals for critical rotating machinery monitoring.

The module provides continuous measurement and monitoring of radial vibration, thrust position, differential expansion, eccentricity, and REBAM, and generates programmable alarms and interlocks to support machinery protection and condition monitoring strategies.

It is fully compatible with Bently Nevada 3300 / 3301 series eddy current probes (e.g., 330105, 330106) and installs directly into a standard 3500 system rack.

Core Functions

Proximity sensor signal processing and conditioning

Monitoring of:

Radial vibration

Thrust position

Differential expansion

Shaft eccentricity

REBAM

Programmable alarm and trip logic

Buffered outputs for external monitoring and control systems

Suitable for hazardous area signal isolation

System Compatibility

Bently Nevada 3500 System Rack

Compatible proximity probes: 3300 / 3301 series

Certifications

Explosion-proof / Hazardous location approval

Class 1, Division 2 (cNRTLus)

Installation & Mechanical Specifications

Installation method: 3500 system I/O rack card slot

Protection level: IP20 (installed inside control cabinet)

Front panel indicators:

OK

TX / RX

Bypass

Weight: approx. 2 kg

Power Supply

Powered via 3500 rack backplane

Sensor excitation: –24 V DC

Key Technical Parameters

Channel Configuration

4 independent, fully programmable channels

Input Characteristics

Input impedance:

Standard: 10 kΩ

TMR parallel mode: 50 kΩ

Sensor Sensitivity

Radial / Thrust / Eccentricity:

3.94 mV/mil

155 mV/mm

Signal Conditioning

Programmable static and dynamic parameters, including:

Direct (DC) value

MAP

1X / 2X amplitude and phase

Outputs

Buffered sensor output per channel

Short-circuit protected

Supports 4–20 mA analog output

Supports relay alarm outputs

Power Consumption

Typical: 7.7 W

Environmental Conditions

Operating temperature: –30 °C to +65 °C

Relative humidity: 5% to 95%, non-condensing

Isolation & Safety

Built-in isolation safety barrier

Suitable for signal isolation in hazardous areas

Typical Applications

Turbine and compressor shaft vibration monitoring

Thrust bearing position protection

Differential expansion monitoring

Critical rotating machinery protection systems

Hazardous-area machinery installations

ENTLY 3500/40-03-01 4-Channel Preamplifier Monitoring Module