The Bently Nevada 3300/46 Differential Expansion Monitor is a rack-mounted module designed to measure the relative expansion between a turbine rotor and its casing. This measurement is critical in steam turbines and other large rotating machinery where thermal growth can cause mechanical interference. The monitor continuously compares expansion values against alarm setpoints, providing early warning of abnormal conditions and protecting equipment from damage.
Features
Measures differential expansion between rotor and casing
Continuous parameter comparison against alarm setpoints
Relay actuation for Alert and Danger conditions
LED indicators for OK, Bypass, Alert, and Danger status
Compatible with standard proximity probe inputs via Proximitor sensors
Technical Specifications
Model
3300/46-XX-XX-01-00
Brand
Bently Nevada
Series
3300
Operating Temperature
0 to 60 degC
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 degC
Output Signals
+4 to +20 mA, +1 to +5 VDC, 0 to -10 VDC
Installation Guidelines
Ensure the 3300 rack is properly grounded to a clean earth point to minimize electrical noise.
Always power down the rack before inserting or removing the monitor module to prevent damage to the backplane connectors.
Use shielded cables for all transducer inputs to protect against EMI in industrial environments.
Verify that the probe configuration matches the specific module suffix settings for accurate measurement.
Ensure adequate ventilation within the cabinet to maintain the operating temperature range of 0 to 60 degC.
FAQ
What is the primary function of the 3300/46 monitor?
This module is designed to monitor the differential expansion between the rotor and the casing of rotating machinery, such as steam turbines, to prevent mechanical interference caused by thermal growth.
Does this module include relay outputs?
Yes, the 01 suffix indicates a single relay output configuration for Alert and Danger alarm conditions.
What type of sensors does this module support?
It is designed to accept inputs from proximity probes via Proximitor sensors.
