Bently Nevada 7400252-055 Eddy Current Proximity Probe Unit

Module Feature

7400252-055 is a hermetically sealed eddy current proximity probe belonging to Bently Nevada 3300 XL series.

It is used to measure shaft radial vibration, thrust axial position and probe-to-shaft gap. It adopts stainless steel sealed structure, suitable for oil mist and moderate high temperature environments. It must be matched with extension cable and proximitor monitor to form a complete measurement chain. It complies with API670 machinery protection specification, widely stocked as spare for power, petrochemical turbine, compressor and pump monitoring cabinet.

Working principle

High-frequency alternating magnetic field is generated by the coil inside the probe tip.

When the conductive metal shaft is close, eddy current is induced on the shaft surface, changing the coil impedance. The matched proximitor converts impedance variation into gap voltage value. The monitoring system calculates vibration amplitude and position offset, for real-time trend display, alarm and trip protection.

Onboard components

Eddy current coil, ceramic insulating tip, hermetically sealed stainless steel housing, integrated shielded coaxial cable and shielding assembly.

LED indicators

No built-in LED indicator.

Hardware self‑diagnosis

Check cable continuity, insulation resistance and gap voltage through the rack monitor. No local adjustment function.

Programming software

Not applicable, passive probe, configured via Bently Nevada System 1 monitoring software.

Electrical & Process Parameters

Model: 7400252-055 Brand: Bently Nevada Device type: Eddy current proximity probe Function: Non-contact shaft displacement and vibration measurement for rotating machinery protection

Mechanical & Structure

Mounting: Thread stud mounting on probe bracket or equipment casing Protection class: Hermetically sealed Housing: Stainless steel probe body

Environmental

Operating temperature: -55℃ ~ +177℃ Storage temperature: -60℃ ~ +200℃ Ambient humidity: 5~95% non‑condensing

Certification: CE Status: Original Bently Nevada monitoring spare

Installation

Cut off monitoring rack power before replacement.

Screw probe onto cleaned mounting stud, lock the lock nut, connect matched extension cable, set installation gap, verify gap voltage and signal reading after commissioning.

Interface

Coaxial signal connector, matched extension cable interface.

Diagnostic

Probe fault: Cable open/short circuit, coil internal damage. Gap voltage offset: Improper installation gap or unsuitable target material. Signal jitter: Bracket vibration or loose lock nut.

Product Brief

7400252-055 probe, Bently Nevada 3300 XL eddy current proximity probe spare for turbine and compressor shaft vibration and axial position monitoring replacement.