Description

The Bently Nevada 3300/45-02-01-03-00, also cataloged as the 3300/45 Dual Differential Expansion Monitor, serves as the primary 3300/45 Dual Differential Expansion Monitor utilized to execute continuous axial rotor growth tracking across 3300 Series Monitoring System platforms.

Hardware Specifications

Machinery Monitoring and TSI Characteristics

The module drives proximity transducer loops directly and delivers the stabilized DC power necessary for correct eddy-current probe scaling. Consequently, the monitoring circuit performs continuous gap voltage validation (-10 VDC targets) to track the absolute displacement between the machine casing and the rotor collar. The internal analog hardware filters high-frequency components to translate raw sensor inputs into a stable dc voltage representing thermal growth during turbine startup and shutdown phases. Simultaneously, the module maintains sharp cross-talk suppression between close-paired transducer tips to prevent mutual inductive interference from corrupting the individual channel measurements.

Frequently Asked Questions

Q: How does the operator configure the monitor for single-channel applications?

A: The engineer sets an internal circuit board jumper to turn off Channel B. Consequently, this action defeats the Channel B “Not OK” status loop, which prevents unassigned sensor inputs from keeping the system rack in a permanent alarm state.

Q: What impact does a short circuit on the recorder line have on the monitor functionality?

A: The module contains short-circuit protected recorder outputs. Therefore, a physical short on the +4 to +20 mA loop limits current internally without disrupting the primary machinery protection logic or backplane data streaming.

Field Installation Guidelines

• Connect the outer shield of the proximity probe extension cable exclusively to the designated monitor rack bulkhead ground terminal to prevent ground loops.
• Adjust the mechanical probe positioning during assembly until the multimeter reads the targeted center-gap voltage before locking down the sensor mounting brackets.
• Maintain a minimum of five full thread engagements on all rear terminal screws to shield the monitoring loop from intermittent signal dropouts.
• Route the low-level transducer field lines inside dedicated, grounded metal conduits separated from any switching AC power distribution lines.