BENTLY 288062-02 Two‑Channel Tachometer Module – Precise Speed and Zero‑Speed Monitoring for Bently Nevada 3500 Racks

The BENTLY 288062-02 is a two-channel tachometer module designed for use in Bently Nevada 3500-series machinery protection systems. From my experience, plants choose this module when they need dependable shaft speed, zero-speed, and overspeed alarming tied into existing 3500 racks without adding a separate controller. You might notice that it’s especially helpful on turbines, compressors, fans, and critical pumps where clean Keyphasor or magnetic pickup signals are already present.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days
• Lead time: In stock typically ships in 1 week; no more than 1 month at the latest
• Payment: 50% advance payment; full payment prior to delivery
• Express options: FedEx, UPS, DHL

Key Features

• Two independent speed channels – Each channel processes tachometer pulses for speed and direction (when supported by sensor/pulse train).
• Compatible inputs – Typically supports Keyphasor/proximity probe pulses and magnetic pickups used across Bently Nevada installations.
• Zero-speed and overspeed alarming – Configurable setpoints for safe start-up, coast-down, and protection during process upsets.
• Front-panel buffered outputs – Convenient access to raw pulse signals for portable analyzers and commissioning checks.
• Rack-integrated – Plugs into a 3500 rack slot; alarm states, OK status, and data are available to the system display and gateway modules.
• Secure trip logic via the rack – Works with system relay modules for voting/trip schemes without external relays in many cases.
• Service-friendly configuration – Parameters are configured through the 3500 system tools; no external power or handhelds required.

Technical Specifications

Application Fields

This module is typically specified on rotating equipment where reliable speed monitoring and trip logic are needed:

• Steam and gas turbines – Speed, zero-speed, and turning-gear interlocks
• Centrifugal and axial compressors – Overspeed protection and process shutdown integration
• Large motors and generators – Start sequence validation and run-permissive checks
• Fans, blowers, and critical pumps – Belt/slip detection and machine protection
• Paper, metals, and petrochemical lines – Line speed feedback and alarm tie-ins with DCS/PLC

One thing I appreciate is how easily it ties into existing Keyphasor proximity probe systems (for example, with 3300 XL probes) without reworking cabinets. A maintenance lead at a fertilizer plant told me they enabled zero-speed trips in under an hour after wiring the magnetic pickup and setting thresholds.

Advantages & Value

• Reliability – Built to the same standards as Bently Nevada vibration monitoring; stable operation in harsh environments.
• Compatibility – Integrates cleanly with 3500 racks, display modules, relay modules, and Modbus gateways already in service.
• Cost and footprint – Two channels in a single slot reduces cabinet space and extra third-party hardware.
• Maintainability – Buffered outputs and rack-based configuration simplify commissioning and troubleshooting.
• Lifecycle support – Spares, configuration tools, and field service are widely available for the 3500 platform.

Installation & Maintenance

• Cabinet and environment – Install in a Bently Nevada 3500 rack inside a clean, dry enclosure with adequate ventilation; avoid corrosive atmospheres.
• Wiring – Use shielded, twisted-pair signal cables for proximity probes or magnetic pickups; ground shields at the rack end to minimize noise.
• Sensor setup – Verify probe gap and target runout; confirm correct pulse-per-revolution settings for accurate speed.
• Alarm setpoints – Define zero-speed, underspeed, and overspeed thresholds with appropriate delays; test trips through the rack’s relay logic.
• Routine checks – Periodically validate pulse integrity via buffered outputs; review event logs and, if applicable, keep rack firmware current.
• Spare strategy – In many cases, plants keep one spare module per rack or per unit to reduce downtime risk.

Quality & Certifications

• Typically conforms to CE requirements for industrial environments
• CSA/UL certifications are common on 3500-series modules (model-dependent)
• RoHS compliance on most modern builds
• Manufacturer’s warranty typically applies; our supply warranty is 365 days

Suggested Supporting Components

• Bently Nevada 3500 rack, power supply, and display modules
• Keyphasor/proximity probe systems (e.g., 3300 XL series) or magnetic pickup sensors
• 3500 relay module for trip output voting and shutdown circuits
• 3500 communications gateway (e.g., 3500/22M) for Modbus TCP/serial integration with DCS/PLC

If you’re replacing an older tachometer card, send your existing rack configuration or the current pulse-per-rev details. It seems to speed up configuration and avoids nuisance trips during the first startup.