Description
The Bently Nevada 3500/40M-01-00 is a four-channel machinery protection monitor designed exclusively to process inputs from proximity transducer systems. It conditions these raw eddy-current probe signals to calculate dynamic values—such as radial vibration and eccentricity—and static values like thrust position or differential expansion. The monitor continuously compares these values against user-configured alarm limits to execute automated hardware shutdowns via the rack’s relay modules.
Commercial & Availability Status
- Product Condition: New Original (New Surplus) in factory-sealed packaging
- Warranty Period: 12-month comprehensive technical warranty
- Availability: In stock at our global warehouse facilities
- Estimated Lead Time: Ships within 1 to 3 business days worldwide via DHL/FedEx
- Pricing Notice: Price subject to market conditions; contact us for a firm quote
Technical Specifications
| Parameter | Value |
| Brand | Bently Nevada (Baker Hughes) |
| Model Number | 3500/40M |
| Option Structure | -01-00 (Proximitor I/O Module with Internal Terminations) |
| Channel Capacity | 4 fully independent channels |
| Transducer Compatibility | Bently Nevada 3300, 7200, and 3300 XL Proximitor Systems |
| Power Consumption | 7.7 W typical |
| Signal Digitization | 24-bit sigma-delta analog-to-digital conversion |
| Measurement Accuracy | Direct/Gap/1X/2X: ±0.33% of full-scale value |
| Transducer Power Supply | −24 V DC outputs per channel |
| I/O Termination Style | Internal Terminations (terminal strips on backplane) |
| Operating Temperature | −30 to +65 °C |
| Storage Temperature | −40 to +85 °C |
| Hazardous Area Certifications | ATEX, IECEx, Class I, Div 2 / Zone 2 (verify with OEM datasheet for specific regional markings) |
Configuration Code Breakdown
The model designator 3500/40M-01-00 specifies a distinct physical and regulatory hardware selection:
- 3500/40M: The main four-channel Proximitor monitor processing card. The “M” designation signifies Enhanced Data Acquisition capability, allowing advanced transient and steady-state dynamic data capture for 3500 system software interfaces.
- -01: Proximitor I/O Module with Internal Terminations. This dictates that the field cables coming from the Proximitor sensor extension wires land directly on the terminal blocks fixed on the back of the 3500 rack.
- -00: No specialized localized agency approvals are associated with this hardware option block. Standard baseline global CE compliance remains active.
Engineering Field Notes & Integration Constraints
Critical Application Context: Unlike the more generalized 3500/42M (Proximitor/Seismic) module, the 3500/40M is built strictly for proximity-based eddy-current systems. Do not connect moving-coil velocity sensors or piezoelectric accelerometers to this module, as the input impedance (10 kΩ) and firmware logic are tailored for −24 V DC Proximitor modulation.
Firmware and Channel Pair Limitations
Configuration is performed using the 3500 Rack Configuration Software. Note that the processing channels are paired in silicon (Channels 1 & 2, and Channels 3 & 4). While you can mix different proximity configurations—such as configuring Channel 1 for Radial Vibration and Channel 2 for Thrust Position—both channels in the pair must share similar transducer types (e.g., matching a 3300 XL 8mm system’s scale factor of 7.87 mV/µm) to prevent digital processing faults.
Common Ground Isolation Hazards
Because the -01-00 variant uses internal terminations directly on the rack backplane, special care must be taken with the shield wires. Sensor shields must float at the physical machine housing and ground only at the 3500 rack chassis terminal. Breaking this convention creates ground loop paths that disrupt the 24-bit signal conditioning, throwing false “Not OK” status indicators or introducing severe 50/60 Hz line-frequency interference into the vibration readings.
Frequently Asked Questions
Can I replace an existing 3500/40M module with a 3500/42M module?
While the 3500/42M can be configured to read proximity sensors, it uses a different firmware profile and channel structure. You cannot simply pull a 3500/40M module and drop in a 3500/42M without modifying the overall rack configuration file and downloading the updated hardware matrix to the Transient Data Interface (TDI).
What is the function of the coaxial ports on the front face of the module?
These are buffered transducer outputs. Each of the four channels features an independent BNC connector that supplies an unisolated, raw voltage replication of the proximity sensor signal. These ports are short-circuit protected and allow diagnostic instruments (e.g., dynamic signal analyzers) to capture raw waveform data without interrupting machinery protection loops.
Can I hot-swap this module while the plant is running?
The main 3500/40M monitor module can be physically pulled from the front slot without turning off power to the rack. However, pulling the active monitor immediately invalidates all 4 channels, dropping their respective OK relays and disabling active machinery protection. Any downstream voting logic or Emergency Shutdown System (ESD) circuits must be placed into manual bypass before extraction.
