The Bently Nevada 3300/47 Differential Expansion Monitor is a rack-mounted module engineered to measure the relative thermal expansion between a turbine rotor and its casing. This measurement is vital for the protection of steam turbines and large rotating machinery, where differential thermal growth can lead to mechanical interference and catastrophic failure. The monitor provides continuous signal conditioning and comparison against pre-configured alarm setpoints to ensure equipment safety.
Features
Continuous monitoring of rotor-to-casing differential expansion.
Dual relay outputs configured for Alert and Danger alarm conditions.
Integrated LED status indicators for OK, Bypass, Alert, and Danger states.
Compatible with standard Bently Nevada proximity probe and Proximitor sensor configurations.
Provides proportional output signals for external data logging and control systems.
Applications
This module is primarily used in power generation and heavy industrial environments for the protection of steam turbines, gas turbines, and large centrifugal compressors where precise monitoring of axial thermal growth is required to prevent mechanical contact.
Technical Specifications
Model
3300/47-XX-XX-02-00
Brand
Bently Nevada
Series
3300
Operating Temperature
0 to 60 deg C
Power Consumption
~1.5 W
Sensitivity
200 mV/mil (8 V/mm) or 100 mV/mil (4 V/mm)
Signal Accuracy
+/- 0.33% typical, +/- 1% max at 25 deg C
Analog Outputs
+4 to +20 mA, +1 to +5 VDC, 0 to -10 VDC
Installation Guidelines
Ensure the 3300 rack is properly grounded according to site electrical safety standards before module insertion.
Handle the module using ESD-safe practices to prevent damage to internal circuitry.
Verify that the module is fully seated in the rack backplane before applying power.
Ensure signal cables from Proximitor sensors are properly shielded and routed away from high-voltage or high-EMI sources.
Always power down the rack or follow site-specific hot-swap procedures before removing or installing the module.
FAQ
What does the 02 relay option provide?
The 02 relay option provides dual relay outputs, allowing the module to trigger independent Alert and Danger alarms based on the measured differential expansion values.
Is this module compatible with all proximity probes?
The module is designed for use with Bently Nevada proximity probe systems. Compatibility depends on the specific probe type and the configuration defined by the second suffix in the model code.
