Bently Nevada 3500/42M (p/n 135489-02) – 4‑Channel Proximitor/Seismic Monitor for API 670 Machine Protection

The Bently Nevada 3500/42M is the workhorse monitor in many protection racks for compressors, turbines, and large motors. It brings four channels of high-integrity vibration and position monitoring into a single two‑slot module, pairing with the rear I/O board p/n 135489-02. From my experience, it’s the go‑to when you need mixed transducer types—eddy‑current proximity probes and seismic (velocity or accelerometer)—without complicating the rack layout.

Typical use cases include radial shaft vibration on sleeve‑bearing machines, thrust (axial) position checks, casing vibration on gearboxes, and bearing housings where you want buffered outputs for diagnostics plus clean, voted relays elsewhere in the rack. You might notice that it integrates neatly with a 3500/22M TDI for Ethernet connectivity to System 1 or a DCS via Modbus TCP, so protection and condition monitoring stay aligned.

“We swapped a mix of older single‑purpose cards for the 3500/42M and cut spare holdings by a third. Setup was quicker than expected, and the buffered outputs made our startup diagnostics much easier.” — Maintenance Lead, Petrochemical Plant

Order Placement Process and Guarantees

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

Key Features

• Four independent channels – Monitor up to four measurements (vibration or position) on one module, which typically simplifies rack planning.
• Mixed transducer support – Accepts eddy‑current proximity probes (Proximitor systems) and seismic sensors (velocity or IEPE/accelerometers) on the same card.
• Protection‑grade alarming – Dual setpoints per channel (Alert/Danger) with latching options and channel bypass for safe commissioning.
• Buffered transducer outputs – Front/rear buffered outputs make field diagnostics and portable data capture straightforward.
• Configurable measurements – Displacement, velocity, or acceleration with appropriate filtering and conversion, which in many cases helps align with API 670 practices.
• Seamless rack integration – Works within the 3500 rack backplane; communicates to the TDI (3500/22M) for Ethernet/Modbus access to plant systems.
• I/O variant p/n 135489-02 – Rear I/O option matched to the 3500/42M monitor; provides terminal connections and buffered outputs as configured.

Technical Specifications

Related or Supporting Products

• Bently Nevada 3500/40M Proximitor Monitor – Similar 4‑channel monitor focused on proximity probes only; 42M adds seismic flexibility.
• Bently Nevada 3500/22M TDI – Required for Ethernet communications, System 1 connectivity, and rack configuration.
• Bently Nevada 3500/32 (or 3500/33) Relay Module – For alarm voting and shutdown relays; pairs with 42M for API 670 protection schemes.
• 3300 XL Proximitor Systems (e.g., 330103 probe, 330130 extension, 3300 Proximitor) – Common proximity probe sets for shaft vibration and thrust position.
• 190501 Velocity Transducer / 330400 Series Accelerometers – Seismic sensors frequently used with the 42M for casing vibration.

Installation & Maintenance

• Panel & cabinet – Mount the 3500 rack in a clean, ventilated cabinet. Maintain clearance for airflow; avoid high‑EMI zones when possible.
• Wiring practices – Use shielded cables for transducers with single‑point grounding. Route sensor and power cables separately to minimize noise.
• Configuration – Set channel type (prox/velocity/accel), full‑scale range, and alarm limits. From my experience, verify OK statuses and phase reference before enabling trips.
• Diagnostics – Use buffered outputs for portable data collectors during startup and balance runs; it appears that this reduces nuisance alarms.
• Routine care – Periodically check terminal tightness, clean dust from the rack, and back up configuration via TDI. Firmware updates (when available) are typically performed through the 3500/22M.
• Calibration – Validate overall readings with simulated inputs or known mechanical conditions; recheck alarm setpoints after major maintenance.
• Safety – Always bypass channels during commissioning and lock out relay voting downstream to prevent unintended trips.

Quality & Certifications

• Designed for API 670‑style machine protection architectures
• CE marking and UL/cUL listings are commonly available for 3500 system modules
• RoHS compliance in most regions (varies by configuration)
• Manufacturer’s warranty: 365 days from delivery

If you’re upgrading an existing 3500 rack, the 3500/42M (with I/O p/n 135489-02) typically drops in with minimal rewiring—especially when you’re already using 3300 XL probes or standard Bently Nevada seismic sensors. Let me know the intended measurements and sensor mix, and I can suggest a practical channel setup and relay voting scheme that avoids false trips during run‑up and coast‑down.