Bently Nevada 177230-02-01-CN Seismic Transmitter for Vibration Monitoring

Introduction

When machinery vibration threatens production uptime, the Bently Nevada 177230-02-01-CN Seismic Transmitter delivers reliable, real-time data to protect your assets. This rugged transmitter converts vibration velocity into a standard 4-20 mA current loop signal, enabling seamless integration with PLC, DCS, and SCADA systems. Designed for harsh environments, it provides accurate measurements from 0 to 50.8 mm/s (0 to 2.0 in/s) over a frequency range of 10 Hz to 1 kHz (600 to 60 kcps) RMS.

Technical Specifications Breakdown

Key parameters include:

• Measurement Range: 0 – 50.8 mm/s (0 – 2.0 in/s) peak velocity, with a full-scale range option of 25.4 mm/s (1.0 in/s) ± 10%.
• Output Signal: 4 to 20 mA current loop from Pin A to Pin B, proportional to peak vibration levels. Sensitivity is calibrated so 4 ± 0.3 mA equals 0.0 mm/s and 20 ± 2 mA equals full-scale range.
• Frequency Response: 3 Hz to 1 kHz ± 10% (180 cpm to 60 kcpm ± 10%), ensuring coverage of common rotating machinery faults.
• Environmental Durability: Operating temperature from -40°C to +85°C (-40°F to +185°F), with 100% non-submerged relative humidity tolerance.
• Physical Construction: 316L stainless steel case and connector, 25.4 mm (1.00 in) diameter, 66.0 mm (2.60 in) height, and weight of 131 g (4.62 oz).

Industry Applications

In industries like oil and gas, power generation, and manufacturing, unplanned downtime from bearing wear or imbalance can cost thousands per hour. For example, on a centrifugal pump, the transmitter’s 4-20 mA loop feeds directly into a DCS, triggering alarms when velocity exceeds 25.4 mm/s. Its ceramic shear sensing element and hermetically sealed design ensure stable performance even in high-humidity or corrosive atmospheres.

Installation & Setup Guidance

Mount the 177230-02-01-CN using the 1/4-28 UNF mounting hole in the body, with a recommended torque of 4 to 7 N-m (35.4 to 62.0 in-lbf). Alternative threads include M6 x 1 SI or M8 x 1.25 SI. Wire the 3-pin MIL-C-5015 connector as follows: Pin A to 4-20 mA positive loop, Pin B to loop return (common for dynamic signal), and Pin C for dynamic acceleration signal (unbuffered, referenced to Pin B). Excitation voltage ranges from 12 to 30 Vdc, current-limited to 40 mA. Allow less than 15 seconds settling time within 2% of final value after power-up.

Maintenance & Reliability

Routine inspection of the connector and cable integrity helps maintain signal accuracy. The 316L stainless steel case resists corrosion, and the hermetically sealed sensor prevents moisture ingress. With a mounted resonant frequency greater than 12 kHz and transverse sensitivity less than 5%, the transmitter minimizes false readings. Shock survivability is rated at 9.810 m/s² (1.000 g peak) maximum drop test. For long-term reliability, verify isolation greater than 10⁸ ohms and isolation breakdown voltage of 600 Vrms with less than 1 mA leakage current.

Compatibility & Integration

This transmitter is designed for use with PLCs, DCS, and SCADA systems that have internal power supplies typically current-limited in the range of 30 mA to 35 mA. The 4-20 mA output simplifies wiring over long distances, making it compatible with most analog input modules. The dynamic acceleration signal on Pin C provides an unbuffered output for additional analysis if needed.