Bently Nevada 3500/50M Tachometer Module

SKU 3500/50

In stock

12-month warranty
Free returns within 30 days

Manufacturer: Bently Nevada
Product No.: 3500/50
Country of origin:United States
Product Type: Tachometer Module
Barcode: 8537101190
Payment: T/T, Western Union
Weight: 820g
Dimensions: 241.3 mm x 24.4 mm x 241.8 mm
Shipping port: Xiamen
Warranty: 12 months

The Bently Nevada 3500/50M is a 2-channel instrument engineered for machinery protection that processes electrical signals from proximity probes or magnetic pickups to evaluate critical shaft parameters. This microprocessor-based module continuously tracks absolute shaft rotative speed, rotor acceleration, or operational phase direction, automatically validating digital measurements against programmable internal setpoints to actuate alert and danger statuses across the 3500 rack network interface.

Key Features

Integrated Phase Synchronization: Configurable to condition transducer source waveforms and supply verified Keyphasor pulses directly across the passive backplane, eliminating the technical necessity for an independent Keyphasor controller card.
Peak Hold Operational Registers: Internal memory matrices autonomously log and capture peak rotative velocity, extreme reverse velocity parameters, and absolute cumulative reverse rotation counts.
Dual Transducer Compatibility: Direct multi-mode operational hardware matches impedance standards for standard eddy current proximity systems and self-generating magnetic sensor pickups.
Dedicated Hardware Watchdogs: Onboard circuit logic continuously updates independent front-panel OK, TX/RX, and Bypass status indicators to give immediate physical health confirmation.
Adjustable Alarm Time Delays: Supports discrete field configuration for Alarm 1 interval structures (1 to 60 seconds in 1-second increments) and Alarm 2 mechanisms (1 to 60 seconds in 0.1-second increments).

Applications

Turbomachinery Diagnostics: Continuous velocity monitoring and acceleration assessment on industrial steam turbines, heavy gas turbines, and process centrifugal compressors.
Reverse Rotation Mitigation: Real-time detection of process backflow conditions in high-capacity fluid pumping systems and multi-stage gas expander trains.
Startup and Coast-Down Profiling: Tracking critical rotor acceleration rates during transient operations through machine critical speeds.
Turning Gear Interlocking: Safe zero-speed confirmation loops to allow automation systems to authorize automatic turning gear clutch engagement.

Ordering Information

Option Code	Selection Parameter Detail
3500/50-AA-BB Base Assembly
AA - 01	I/O Module with Internal Terminations
AA - 02	I/O Module with External Terminations
AA - 04	I/O Module with Internal Barriers and Internal Terminations
BB - 00	Hazardous Area Approval: None
BB - 01	Hazardous Area Approval: CNRTLus (Class I, Division 2)
BB - 02	Hazardous Area Approval: ATEX/IECEx/CSA (Class I, Zone 2)

Technical Specifications

Parameter Category	Engineering Value
Signal Input Capacity	Accepts up to 2 transducer signals
Input Voltage Range	+10.0 V to -24.0 V (internally limited)
Input Impedance Range	20 kOhm (standard), 40 Ohm (TMR), 7.15 kOhm (Internal Barrier)
Power Consumption	5.8 Watts typical
Transducer Supply Output	24 Vdc, 40 mA maximum current per channel
Analog Recorder Outputs	+4 to +20 mA proportional; 0 to +12 Vdc across 0 to 600 Ohm load
Full Scale Maximum Range	99,999 rpm
Maximum Tracking Frequency	20 kHz
Minimum Tracking Frequency	Proximity: 0.0167 Hz (1 rpm for 1 event/rev); Magnetic Pickups: 3.3 Hz
RPM Measurement Accuracy	Under 100 rpm: plus/minus 0.1 rpm; 100 to 10,000 rpm: plus/minus 1 rpm; Over 10,000 rpm: plus/minus 0.01% of true speed
Main Board Dimensions	241.3 mm x 24.4 mm x 241.8 mm (9.50 in x 0.96 in x 9.52 in)
Standard I/O Board Dimensions	241.3 mm x 24.4 mm x 99.1 mm (9.50 in x 0.96 in x 3.90 in)
Main Board Weight	0.82 kg (1.8 lb)
Standard I/O Board Weight	0.20 kg (0.44 lb)
Operating Temperature Limits	-20 Celsius to +65 Celsius (T4 thermal threshold classification)
Manufacturer	Bently Nevada (A Baker Hughes Company)
Country of Origin	United States
Shipping Weight (Calculated)	1.48 kg
Package Dimensions (Calculated)	315 mm x 295 mm x 90 mm

Installation Guidelines

CRITICAL WARNING: This instrument is restricted to machinery asset health monitoring and logical warning annunciation tasks only. DO NOT deploy the 3500/50M module as a standalone device or embedded component in primary emergency overspeed trip loops. It does not possess the structural response speed or protective design redundancy needed for definitive emergency engine or turbine shutdown control. Remove all primary rack power input channels before physically working with backplane components.

1

Wear a functional electrostatic discharge (ESD) strap connected to the metal chassis framework before handling the main processing boards to mitigate internal semiconductor layer failures.

2

Align and secure the Tachometer Main Module into any full-height front slot placement inside the 3500 rack structure, driving the guide paths home until the seat triggers completely.

3

Slide the matching Tachometer I/O Module into the identical slot coordinate at the back of the card rack. Fully tighten the physical retaining screws into the rear mounting plate.

4

Terminate the field sensor cables directly into the rear I/O compression blocks. If configuring low-speed alerts, zero speed updates, or reverse direction detection protocols, avoid magnetic pickups as their low-voltage envelope below threshold targets will impair speed measurement accuracy.

FAQ

Can this tachometer card operate within an emergency machine overspeed shutdown safety loop?

No. The module is structurally engineered and restricted for condition monitoring and alarming functions only. It lacks the execution speed and architecture required to act as a primary emergency overspeed safety shutdown system.

Why are proximity probes preferred over magnetic pickups for zero speed tracking?

Magnetic pickups are passive sensors whose output voltage amplitude drops proportionally to the rotational velocity. At ultra-low speeds, the signal level drops below the processing threshold of the input hardware, which prevents valid zero speed detection.

Is an external Keyphasor module required when using this device?

No. The module can be configured via rack software to condition the sensor inputs and supply raw Keyphasor synchronization pulses directly over the internal chassis backplane to all other modules.

What are the standard integrated electrical power limits for the transducer supply loops?

The module contains an integrated voltage supply that delivers a constant -24 Vdc source with an absolute current output limit of 40 mA per monitoring channel.

View all FAQs →

Product Documentation

Technical Datasheet (PDF) Complete specifications and technical drawings.

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Global Express Shipping

Standard Delivery: 4-6 Business Days via DHL, FedEx, and UPS.
Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
Worldwide Coverage: Serving over 150 countries, including rapid delivery to Saudi Arabia and UAE.

Returns & Warranty

30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
12-Month Warranty: Every industrial component is backed by our professional technical warranty.

Orders are processed and delivered Monday-Friday (excluding public holidays).

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TECHNICAL SPECIFICATIONS

Color pattern	Silver Greyish White
Country of origin	United States
Power source	DC Power