Bently Nevada 3500/33 – 16-Channel Failsafe Relay Output Module (149992-02)

Overview

The Bently Nevada 3500/33 – 16-Channel Failsafe Relay Output Module (P/N 149992-02) is a spare output card for the 3500 machinery protection platform. It provides a dense bank of 16 independent relay outputs to drive trips, interlocks, annunciation and safety actions based on alarms generated elsewhere in the 3500 rack. Built with a failsafe design, the module keeps each relay in a defined state during a power loss or controller fault so that critical equipment remains in a safe condition until the system is restored. This makes the 3500/33 a trusted choice for plants that require defensible shutdown logic and high availability on rotating equipment.

What it does

Inside a 3500 rack, the 3500/33 listens to alarm statuses from monitoring cards (vibration/position/process) and converts those alarms into hardwired relay contacts. Each channel is isolated and configurable so you can map alerts and trips to ESD inputs, valve solenoids, pumps, horns, beacons, or PLC/DCS interlocks. When alarms clear—or when latching and reset rules are applied—the module updates its contact states accordingly. Because the relays are failsafe, a loss of power or a controller fault forces a predictable state that preserves safety.

Key capabilities & benefits

• 16 channels, independent: wire alarms and trips to multiple devices without cross-coupling.

• Failsafe behavior: defined relay state on power/system failure supports safety cases and MOC requirements.

• Flexible logic: supports latching / non-latching behavior and voting/masking per your 3500 configuration, enabling strategies such as grouping alarms or applying majority voting before a trip.

• Rack-level compatibility: designed for the Bently Nevada 3500 platform—ideal as a drop-in spare to minimize MTTR and unplanned downtime.

• Audit & reliability: integrates with the rack’s event/alarm logging so shutdowns are traceable for incident review and regulatory audits.

• Simple maintenance: standardized form factor and front access in the 3500 rack help technicians replace and return to service quickly.

Typical applications

• Emergency Shutdown (ESD) initiation on high vibration, axial position, high bearing temperature, or process upsets detected by the 3500 monitors.

• Safety-related control of valves, pumps, trips, motor contactors, solenoids, horns and beacons.

• Redundancy and voting in critical rotating-equipment protection, reducing spurious trips while maintaining protection integrity.

• Annunciation and interlocks to PLC/DCS for operator awareness and automated sequences.

Integration notes

Use the 3500/33 within a standard Bently Nevada 3500 rack alongside the appropriate monitoring modules and system transducers. Alarm logic, latching, voting and time delays are configured in the rack; the relay module executes those commands at the contact level. For brownfield replacements, verify rack/controller part numbers and firmware so the spare aligns with your site standards and alarm mapping.

What’s included

This listing is for one 3500/33 Failsafe Relay Output Module, P/N 149992-02. Terminal blocks, rack hardware and accessories are provided per site configuration or existing rack inventory.

Who should keep a spare

Operators of compressors, turbines, large pumps, fans, blowers and other critical rotating assets running a Bently Nevada 3500 should keep at least one spare 3500/33 on the shelf. Having a ready module on site cuts mean time to repair, helps avoid prolonged bypass conditions, and keeps protection and ESD logic fully available.

Safety note

Because this module influences safety-related actions, installation and configuration should follow your plant’s MOC procedures, approved logic diagrams, and functional test plans (proof-of-trip). Always verify correct alarm mapping and relay behavior before returning equipment to service.

Call to Action

Need to confirm compatibility or receive the official datasheet? Request a quote now and share your rack/controller P/Ns and desired alarm mapping (latching, voting, device list). Our team will verify fit within your Bently Nevada 3500 system, propose a spare strategy, and provide lead time and shipping options.