Description
Description
The Bently Nevada 991-01-XX-01-00 Vibration Transmitter is a two-wire, loop-powered device engineered for the continuous monitoring of rotating machinery. It is specifically designed to interface with 3300 NSv proximity probes, converting raw vibration signals into a standard 4-20 mA output. This output is directly compatible with industrial control systems such as PLCs, DCS, and SCADA, providing a robust solution for machinery protection in environments like compressors, pumps, and fans.
Features
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Loop-Powered Design: Operates on a 24 VDC nominal loop, eliminating the requirement for external power supplies and simplifying field wiring.
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Signal Processing: Converts proximity probe inputs into a proportional 4-20 mA signal for vibration amplitude.
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Diagnostic Circuitry: Features an integrated Not OK/Signal Defeat circuit to prevent false alarms during sensor or cable faults.
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Dynamic Output: Provides both dynamic vibration and gap voltage outputs for advanced diagnostics and signal analysis.
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Calibration: Equipped with a test pin for quick and efficient field calibration.
Applications
This transmitter is ideal for industrial plant applications where reliable, cost-effective vibration monitoring is required for balance-of-plant rotating equipment, including centrifugal compressors, industrial pumps, cooling fans, and blowers.
Technical Specifications
| Model |
991-01-XX-01-00 |
| Brand |
Bently Nevada |
| Output |
4-20 mA (proportional to vibration) |
| Power Supply |
Loop-powered (24 VDC nominal) |
| Operating Temperature |
-40 degC to +85 degC |
| System Compatibility |
3300 NSv Proximity Probes |
Installation Guidelines
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Mounting: The unit supports standard DIN-rail or bulkhead mounting configurations. Ensure the mounting surface is clean and provides adequate heat dissipation.
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Wiring: Use shielded instrumentation cable to minimize EMI/RFI interference. Ensure proper grounding of the cable shield at the control system end only to prevent ground loops.
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Handling: As a precision electronic component, handle with care to avoid ESD damage. Ensure the system is powered down before making or breaking electrical connections.
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Environment: While robust, the unit should be installed in a location protected from direct moisture and extreme corrosive atmospheres unless housed in an appropriate NEMA-rated enclosure.
FAQ
What is the primary function of the 991-01-XX-01-00?
This module acts as a signal conditioner that takes the raw signal from a 3300 NSv proximity probe and converts it into a 4-20 mA signal, which is the industry standard for integration into PLC or DCS monitoring systems.
Does this transmitter require an external power supply?
No, this is a two-wire, loop-powered device. It derives its operating power directly from the 4-20 mA current loop, which simplifies installation and reduces cabling requirements.
What should I do if the Not OK circuit triggers?
The Not OK circuit indicates a fault in the probe, extension cable, or the transmitter itself. Check the integrity of the proximity probe and the cabling connections to the transmitter before verifying the transmitter's internal diagnostics via the test pin.
