Configured for differential expansion and rotor expansion measurement in the Bently Nevada 3300 XL Transducer System, the Bently Nevada 330878-51-05 (330878 3300 XL 50 mm Proximitor Sensor) provides direct signal conditioning and displacement conversion for large rotating equipment monitoring.

Configuration Identification

The 330878-51-05 configuration defines a 3300 XL 50 mm Proximitor Sensor assembly with DIN rail mounting, 5.0 meter system length, and multiple agency approvals.

This Proximitor Sensor operates together with a 50 mm probe and extension cable to form a complete eddy-current transducer system. The large probe coil design provides an extended linear measurement range for differential expansion and rotor expansion applications.

Hardware Specifications

Rotor Expansion Measurement Characteristics

The 3300 XL 50 mm Proximitor Sensor is designed for eddy-current displacement measurement where large axial movement ranges must be monitored.

The system measures differential expansion between the turbine rotor and machine casing by observing the relative movement of a target collar. Two transducer arrangements can be used depending on required measurement range:

• Two probes observing the same side of a collar for redundant measurements.
• Two complementary probes installed on opposite sides of a differential expansion collar to increase measurable range.

The extended linear range of up to 27.9 mm allows monitoring of large shaft movements that exceed the capability of standard 8 mm proximity systems.

Eddy-Current Signal Characteristics

The 330878-51-05 operates as part of the Bently Nevada eddy-current measurement architecture. The Proximitor Sensor supplies excitation and converts probe impedance changes into proportional displacement signals.

The system requires correct probe gap adjustment and calibration to maintain measurement accuracy. Gap voltage validation is used during installation to confirm the probe operates within the intended electrical range.

For rotor dynamics applications, installation geometry and target dimensions must be considered to prevent measurement errors caused by insufficient target surface area or probe interaction.

Ordering Information

The delivered configuration includes:

• 1 x Bently Nevada 330878-51-05 3300 XL 50 mm Proximitor Sensor
• 1 x DIN mount sensor assembly
• 1 x Factory configured sensor housing

Required system components:

• 1 x 3300 XL 50 mm Probe
• 1 x Compatible extension cable
• 1 x Compatible Bently Nevada monitoring input channel

Field Installation Guidelines

Mechanical Installation

• Install the Proximitor Sensor on a suitable DIN mounting location.
• Verify probe, extension cable, and sensor combinations match the required system length.
• Ensure the target surface provides sufficient area for 50 mm probe operation.

Signal Wiring

• Route proximity signal wiring separately from high-voltage power cables.
• Maintain cable shielding and grounding practices according to Bently Nevada installation requirements.
• Avoid unnecessary cable bends or mechanical stress on extension cable connections.

System Calibration

• Verify probe gap voltage before commissioning.
• Confirm displacement output response after mechanical installation.
• Validate monitoring channel configuration before placing equipment into operation.

Frequently Asked Questions

• What measurement does the 330878-51-05 Proximitor Sensor perform?

  It converts eddy-current probe signals into displacement measurements used for differential expansion and rotor expansion monitoring.

• Is the 330878-51-05 a complete proximity transducer system?

  No. It requires a compatible 50 mm probe and extension cable to create a complete transducer system.

• What is the maximum linear measurement range?

  The 3300 XL 50 mm system provides a maximum linear range of 27.9 mm (1100 mils).

• What mounting method is used for this model?

  The 330878-51-05 configuration uses DIN rail mounting for installation inside monitoring cabinets.

• Can this sensor measure standard 8 mm probe signals?

  No. This model is designed specifically for the 3300 XL 50 mm transducer system components.

• What installation factor affects cross-talk performance?

  Proper probe spacing, target size, and mechanical installation arrangement reduce possible cross-talk effects.

• What voltage supply does the Proximitor Sensor require?

  The system operates with a -24 VDC supply as specified for the 3300 XL Proximitor Sensor design.

• Can this sensor connect directly to a PLC input?

  No. It requires a compatible monitoring system input channel designed for Bently Nevada proximity signals.