The Bently Nevada 3300/25, also cataloged as the 3300/25 Dual Accelerometer Monitor, operates as a dedicated hardware component for high-frequency casing vibration processing within Turbine Supervisory Instrumentation (TSI) networks. The module provides continuous electrical processing of dual accelerometer transducer signals, outputting discrete values for machinery protection and analysis loops.

Module Parameters

Casing Acceleration and Rotor Dynamics

While proximity systems evaluate internal fluid-film bearing gaps through precise gap voltage validation (-10 VDC targets) and eddy-current probe scaling, the 3300/25 dual accelerometer monitor targets structural casing transmission path responses. It converts raw high-frequency charge or voltage inputs from casing-mounted sensors to track rolling-element bearing degradation and blade pass frequencies. Processing these high-frequency structural inputs allows the monitor to diagnose complex rotor dynamics phenomena that do not manifest directly as low-frequency oil-film displacements.

Engineering Technical FAQ

Q: How does the module handle the output signal calculation when internal integration is selected?

A: When internal integration is enabled, the monitor changes its frequency range to 10 Hz to 90 kHz and processes the acceleration signals into velocity metrics. This modification alters the tracking profile to measure structural vibration velocity parameters rather than peak acceleration forces.

Q: What is the effect of hot-swapping or active replacement of the 3300/25 monitor module within an energized 3300 rack?

A: The 3300 Series chassis design permits the active extraction or insertion of individual monitor modules under backplane power. However, pulling the active 3300/25 module instantly forces the associated channel relays to open or close based on their configured fail-safe execution state, breaking continuous protection on those monitoring loops.

Q: What is the purpose of the 100 ohm output impedance specification on the monitor ports?

A: The 100 ohm output impedance enables long-distance analog signal distribution to external diagnostic equipment, oscilloscopes, or plant DCS systems without incurring signal degradation or driving the buffering amplifiers into saturation under continuous load.

Field Installation Guidelines

• Rack Seating: Slide the module firmly along the upper and lower chassis guide rails of the 3300 rack until the rear edge multi-pin connector seats completely into the backplane. Secure the front panel thumbscrews to ensure stable electrical engagement.

• Transducer Cable Shielding: Terminate the outer shielding braids of the transducer field wiring exclusively at the 3300 rack terminal block ground bus. The shield must remain floating and insulated at the accelerometer casing end to prevent parasitic ground loops.

• Input Coaxial Integrity: Verify that the field wiring to the 100 mV/g accelerometers matches the nominal sensor impedance. Poor terminations or high-resistance terminal connections will distort high-frequency blade-pass vibration readings above 10 kHz.

• Environmental Routing: Avoid routing the high-impedance accelerometer input lines parallel to high-voltage AC three-phase motor cables or switching inverter conduits to limit electromagnetic noise injection.

Package Kit Inclusions

• Package Contents: One 3300/25 dual accelerometer monitor module assembly with integrated front-panel display matrix and retention hardware.

• Excluded Hardware: This catalog item does not include the 3300 system rack housing, rear terminal input/output blocks, accelerometers, or interconnecting field cables.

Logistics and Packaging Controls

• Fulfillment Lead Time: Delivery time: 2-7 days when payment finish, utilizing expedited international logistics routes via DHL, FEDEX, or UPS.

• Industrial Boxing: The component is dispatched enclosed inside specialized anti-static industrial packaging complete with shock-absorbent structural cells to protect the calibrated analog filter networks from mechanical shock and static discharge.