Description
Bently Nevada 3300/20 Dual Vibration Monitor
Configured for radial shaft vibration measurement in the 3300 Series Turbine Supervisory Instrumentation (TSI) network, the Bently Nevada 3300/20-12-01-00-00-00 (3300/20 Dual Vibration Monitor) provides direct physical execution of dynamic proximity probe signal processing and alarm relay switching.
Suffix Breakdown & Model Matrix
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Option Code
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Description
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Specification
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-12
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Full-Scale Range
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0 - 5 mils Peak-to-Peak
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-01
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Transducer Input
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3300 or 7200 5mm/8mm Proximitor Sensor (200 mV/mil)
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-00
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Agency Approval
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FM Ordinary Locations
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-00
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Intrinsically Safe
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None
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-00
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Relay Execution
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Standard Relays
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-00
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Resistor Mod
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Standard
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Hardware Specifications
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Parameter
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Specification
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Model Brand
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Bently Nevada 3300/20
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Origin
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United States
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Weight
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Approx. 0.5 kg (estimated)
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Dimensions
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Standard 3300 Series Half-Rack Module
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Operating Temp
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0 degC to +65 degC
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Power Consumption
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5 W typical
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Input Signal
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2 independent eddy-current probe channels
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Input Impedance
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10 kOhm nominal
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Frequency Response
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10 Hz to 1000 Hz @ -3 dB
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Accuracy
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+/-0.5% of full scale
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Output Signals
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4-20 mA recorder outputs, Buffered outputs
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Eddy-Current Probe Scaling and Gap Validation
The module utilizes a fixed scaling factor of 200 mV/mil derived from the Proximitor sensor input. System integrity relies on maintaining a target gap voltage validation point of -10 VDC to ensure linear transducer operation. The monitor incorporates inherent cross-talk suppression between Channel A and Channel B to prevent signal interference during high-vibration events, ensuring accurate representation of rotor dynamics without adjacent channel contamination.
Frequently Asked Questions
Q: Does the 3300/20 support hot-swap replacement while the rack is powered?
A: No. The 3300/20 does not support hot-swapping. Rack power must be removed before removing or inserting the module to prevent damage to the backplane interface and internal relay circuitry.
Q: What is the required gap voltage for the 3300/20-12 configuration?
A: For the 200 mV/mil scaling, the standard static gap voltage should be set to -10 VDC relative to the common reference to ensure the dynamic vibration signal remains within the linear range of the probe.
Q: Is the spare part 135322-01 pre-configured for the -12-01 options?
A: No. The 135322-01 is a bare main circuit board. It requires manual configuration of jumper settings and EPROM insertion to match the specific suffix codes of the original 3300/20 unit.
Field Installation Guidelines
Install the module into the 3300 rack by aligning the card guides and applying even pressure until the front panel mates with the backplane connector. Ensure the chassis ground lug is securely fastened to the panel earth. When wiring the transducer inputs, use shielded twisted pair cable. Terminate the shield drain wire directly to the ground terminal on the I/O module block; do not connect the shield at the probe end to avoid ground loops. Verify the gap voltage at the probe termination point prior to energizing the system.
