The Bently Nevada PWA 72752-01-AH is a precision digital tachometer module belonging to the legacy 7200 Series monitoring system, specifically designed to provide accurate speed measurement and overspeed protection for critical rotating machinery.
Product Parameters (Datasheet)
- Model Number: 72752-01-AH
- Series: 7200 System
- Device Type: Digital Tachometer Module (TACH RPM)
- Input Signal: Compatible with Bently Nevada Proximity Probes (Proximitor systems)
- Measurement Range: Supports a wide RPM range (typically up to 99,999 RPM)
- Accuracy: High-precision digital frequency-to-RPM conversion
- Display: Integrated 5-digit digital display for local speed monitoring
- Alert/Danger Setpoints: User-adjustable alarm thresholds for overspeed conditions
- Output: Analog proportional output (typically 4-20mA or 0-10V) for remote monitoring
- Revision: AH (Specific hardware/firmware iteration for the PWA assembly)
Country of Origin
This instrumentation module was manufactured by Bently Nevada (a Baker Hughes business) in the United States, adhering to the rigorous reliability standards required for machinery protection.
Application Fields
The 72752-01-AH is primarily utilized in heavy industrial environments where rotational speed is a critical safety and process variable:
- Power Generation: Monitoring steam and gas turbine shaft speeds.
- Oil & Gas: Overspeed protection for centrifugal compressors and expanders.
- Mining & Metals: Speed regulation for large conveyors and grinding mills.
- Water Treatment: Monitoring industrial pump speeds and motor performance.
Product Usage Instructions
- Installation: Insert the module into a compatible 7200 Series rack. Ensure the locking mechanisms are engaged to maintain a secure connection to the backplane.
- Transducer Connection: Connect the output from a Proximitor sensor (viewing a notched shaft or keyway) to the module’s input terminals.
- Configuration: Calibrate the module based on the number of “events per revolution” (e.g., the number of notches or keys on the shaft).
- Setpoints: Adjust the “Alert” and “Danger” potentiometers or switches to the desired overspeed trip levels to ensure machine safety.
- Monitoring: Use the front-panel BNC connector to buffer the raw transducer signal for diagnostic analysis with an external oscilloscope or data collector.
Product Technical Description
The 72752-01-AH functions as a sophisticated frequency counter. Technically, it processes the voltage pulses received from a proximity probe as it detects a target on a rotating shaft. The module converts these pulses into a highly accurate RPM value displayed on the front panel. Beyond simple monitoring, the PWA 72752-01-AH provides critical protective logic; if the measured RPM exceeds pre-defined safety limits, the module activates its internal relays to trigger an alarm or initiate an emergency machine shutdown (trip).
Q&A (Common Questions)
Q: Can this module be used with any proximity probe? A: It is specifically designed to work with Bently Nevada 7200 Series 5mm or 8mm proximity probe systems.
Q: What is the purpose of the “Buffered Output” on the front panel? A: This provides a clean, raw signal from the probe that allows vibration technicians to perform detailed analysis without interrupting the module’s protective functions.
Q: Does the module store peak RPM values? A: Yes, many 7200 series tachometers feature a “Peak Hold” function to capture the maximum speed reached during a startup or trip event.
Q: Is the 7200 Series still in active production? A: The 7200 Series is a legacy system. While no longer in primary production, refurbished and surplus modules like the 72752-01-AH remain vital for maintaining existing installed systems.
Similar Model Recommendations
- Bently Nevada 3500/50 (Modern digital tachometer successor)
- Bently Nevada 72752-02 (Alternative range/feature variant)
- Bently Nevada 72751 (Related 7200 Series speed monitor)
- Bently Nevada 3300/50 (Next-generation tachometer module)
- Bently Nevada 72752-01-BA (Different revision of the same module)
For more information on the Bently Nevada 72752-01-AH and other machinery protection modules, please contact our technical sales team.
