Configured for continuous vibration monitoring in 3300 System platforms, the Bently Nevada 3300/55-01-04-12-12-00-00-07-00 (3300/55 Dual Velocity Monitor) provides direct physical signal processing for two independent velocity inputs. This module processes incoming transducer signals to provide real-time velocity magnitude tracking and alarm logic execution.

Model Configuration Breakdown

• Monitor Type: 3300/55 Dual Velocity Monitor

• Channel Input: 01 - Dual Velocity Inputs, Channels A & B indicate in peak velocity

• Transducer Type: 04 - Velomitor 100 mV/in/s

• Full-scale Range (Ch A & B): 12 - 0 to 1 in/s pk

• Agency Approval: 00 - None

• Intrinsic Safety Barrier: 00 - None

• Alarm Relay: 07 - Hermetically-Sealed (Velomitor)

• Trip Multiply: 00 - None

Hardware Specifications

Mechanical Monitoring and Transducer Dynamics

The 3300/55 monitor requires precise signal conditioning to ensure accurate rotor dynamics analysis. When utilizing Velomitor sensors, the input stage compensates for frequency response characteristics typical of seismic velocity transducers. Signal integrity must be maintained through proper shield grounding at the monitor termination point to prevent noise injection. Unlike eddy-current probe systems which require -10 VDC gap voltage validation, the velocity input channel focuses on AC signal amplitude conversion and integration to peak velocity values. Users should ensure that input cabling maintains high common-mode rejection to minimize cross-talk suppression issues in dense rack configurations.

Ordering Info

• 1 3300/55 Dual Velocity Monitor Module

• 1 Front panel terminal block assembly

• 1 Configuration documentation set

Installation Guidelines

• Rack Insertion: Slide the monitor into the designated slot within the 3300 rack. Ensure the backplane connector is fully seated before securing the front panel screws.

• Wiring Termination: Utilize shielded twisted-pair cabling for transducer inputs. Connect the cable shield to the designated instrument common (COM) point at the terminal block to minimize EMI.

• Configuration: Verify all switch settings on the internal module boards match the intended full-scale range before applying rack power.

• Validation: Confirm signal input by verifying output signal amplitude using a calibrated signal generator prior to connecting live machine sensors.

Frequently Asked Questions

• Does this module support hot-swapping?

  The 3300/55 monitor is designed for hot-swapping within an energized 3300 rack. Ensure the system is in a maintenance state if alarm relays could trigger unintended machinery shutdowns.

• What is the input impedance for the Velomitor channel?

  The input impedance is calibrated to match the 100 mV/in/s output of standard Bently Nevada Velomitor transducers, ensuring no loading effect on the signal.

• Can I use this for non-standard full-scale ranges?

  The full-scale range is hard-coded via the model ordering options. Field modification requires specialized equipment and is generally not recommended for certified monitor calibration.

• Is the relay output isolated?

  Yes, the hermetically-sealed relay outputs provide electrical isolation between the monitor logic circuits and the external alarm or trip annunciation systems.

• How does the Trip Multiply function work?

  Trip Multiply allows the operator to temporarily increase alarm setpoints during machine start-up, preventing false trips due to transient vibration levels.

• What happens if the transducer signal is lost?

  The module includes built-in OK circuitry that will trigger a fault indication if the transducer signal falls outside the valid operating voltage range.

• Is an external safety barrier required?

  This specific model includes no intrinsic safety barriers. It is intended for non-hazardous locations or systems where barriers are provided at the rack interface level.

• How is the module calibrated?

  Calibration should be performed using a signal simulator that provides a 100 mV/in/s equivalent AC signal to verify both the channel readouts and relay setpoint actuation.