The Bently Nevada 286566-02, also cataloged as the 3500/50M Tachometer Module, operates as a dedicated hardware component for frequency-to-voltage signal conversion and speed monitoring within the 3500 Machinery Protection System. This module processes input from eddy-current proximity probes or magnetic pickups to determine shaft rotational speed, providing primary protection and alarming functions based on pre-configured setpoints.

Configuration Matrix

The 286566-02 model represents a standard 3500/50M Tachometer configuration utilizing internal signal processing circuitry compatible with standard 3500 series backplanes. The specific hardware implementation incorporates discrete signal processing paths for non-contact sensing inputs. No alternative modular configurations are denoted within this specific part number subset.

Physical & Electrical Metrics

Bently Nevada TSI Mechanical Monitoring Characteristics

The 3500/50M module utilizes transducer signal conditioning specifically optimized for eddy-current probe scaling. This includes validation of -10 VDC targets for mid-gap positioning, ensuring that sensor inputs maintain linearity across the operational range. The module suppresses cross-talk between high-speed input channels through localized signal isolation, preventing interference from adjacent proximity probe signals. By monitoring rotor dynamics via frequency-to-voltage conversion, the module executes setpoint comparisons that trigger the onboard SPDT relays when input frequencies exceed velocity threshold parameters.

Ordering & Logistics

• Unit includes the 3500/50M Tachometer Module (286566-02).

• Standard shipment includes the module assembly and static-shielded packaging.

• Additional components such as I/O modules, terminal blocks, or configuration software must be ordered separately.

• Certification documentation, including Certificate of Origin, is issued upon order fulfillment.

Field Deployment Procedures

• Ensure the module is seated into the 3500 rack backplane with proper alignment of the male/female interface pins.

• Tighten front-panel captive screws to ensure solid chassis ground and electrical contact.

• Verify input signal wiring is shielded twisted-pair to mitigate electromagnetic interference in the instrument rack.

• Ensure the I/O module matching the tachometer is installed in the rear of the rack to provide terminal connections for transducer signals.

• Observe the LED status indicators upon power-up to confirm the module has passed self-diagnostic routines.

Technical Inquiry FAQ

• What is the response time for the relay actuation?

  The relay actuation time is determined by the configured alarm delay; typically, signal processing and relay closure occur within 50 ms to 100 ms of the threshold breach.

• Can this module be hot-swapped?

  Yes, 3500 series modules are designed for hot-swap capability; however, ensure the rack is in a safe operational state to avoid unintended trip triggers.

• What signal types are supported?

  The module supports inputs from proximity probes, magnetic pickups, and active speed sensors requiring voltage-level input switching.

• How is the speed calculated?

  The module calculates speed based on the frequency of input pulses detected from a target (e.g., keyway or gear tooth) per time unit.

• Are the relays configurable?

  Yes, the SPDT relays are programmable via the 3500 configuration software to act based on high, low, or danger trip setpoints.

• What is the significance of the gap voltage?

  Gap voltage confirms the sensor probe is properly positioned within its linear range relative to the target, ensuring accurate frequency capture.

• Does the module require an external I/O module?

  Yes, the 3500/50M functions in conjunction with a corresponding I/O module located in the rear of the rack to provide wiring terminals.

• What is the impact of power failure?

  The module enters a fail-safe state where relays are de-energized, reflecting the lack of power to the monitoring loop.