3300/45-XX-01-03-00 Bently Nevada Dual Differential Expansion Monitor

Hardware Specifications

Measurement and Signal Processing

The monitor processes two proximity transducer signals to evaluate differential expansion as the rotor and casing respond differently to temperature changes. Both measurement channels support observation of expansion magnitude and direction. The selected transducer scale factor must match the applicable probe characteristics and measurement range to ensure correct interpretation of the displayed values.

Recorder Outputs and Buffered Signals

Each channel provides a configurable recorder output for external indication or recording. The available output formats are 4-20 mA, 1-5 VDC, and 0 to -10 VDC. The current output supports a specified load resistance of 0 to 600 Ohm.

Buffered transducer signals are available through front-panel coaxial connectors and rear-panel terminals. These connections allow access to the channel signals for suitable external measurement equipment. The documented buffered output impedance is 100 Ohm, with short-circuit protection.

Alarm Functions and Display

Each channel has independently adjustable Alert and Danger thresholds. The front-panel LCD provides a 63-segment bargraph for each channel, including a center scale for probe-gap indication. The OK, Alert, Danger, Bypass, and First Out indicators help operators identify measurement status and alarm conditions.

The alarm settings cover 0% to 100% of full scale, with a stated repeatability of +/- 0.4% of full scale. The display resolution limits the practical adjustment increments; setpoint adjustment resolution should not be confused with measurement accuracy.

Configuration and Selection

The ordering code identifies the monitor family and its configuration options. However, the supplied model 3300/45-XX-01-03-00 contains XX as an unspecified range option, so the exact full-scale measurement range cannot be established from this designation alone.

Before selecting a replacement, verify the full-scale range, transducer input option, alarm relay configuration, and agency approval option against the installed unit’s complete part number and applicable ordering documentation. Do not assume that a similar 3300/45 model has identical settings or hardware.

Frequently Asked Questions

Q: What does the Bently Nevada 3300/45 monitor measure?

A: It measures differential expansion, which represents the relative axial movement of a turbine rotor and its casing. The monitor tracks both the magnitude and direction of the measured movement.

Q: Can both measurement channels have independent alarm settings?

A: Yes. Each channel supports its own Alert and Danger setpoints. Channel B can also be switched off when the application requires measurement at only one location.

Q: How can I confirm the correct replacement configuration?

A: Check the complete part number, full-scale range, transducer input selection, relay option, and agency approval code. The XX field in the supplied model does not identify a specific full-scale range.