Configured for integration with PLC and DCS platforms, the Bently Nevada 177230-02-01-05 (177230 Series Seismic Transmitter) converts broad-band seismic vibration into a proportional 4-20 mA analog current loop signal.

Electrical & Mechanical Characteristics

Cross-Talk Suppression and Loop-Powered Interface

The ceramic shear-element design provides high rejection of base-strain and transverse motion, minimizing cross-talk from adjacent machinery. The device operates as a 2-wire loop-powered transmitter, sourcing current proportional to RMS vibration velocity. It requires no field calibration or zero adjustment. Signal linearity is maintained across the 12-30 VDC excitation range, allowing direct interface to analog input cards without external signal conditioners.

Technical Performance FAQ

• Does the 177230 support HART communication? No, this device outputs a raw 4-20 mA analog signal and does not support digital protocol overlays.

• What is the maximum allowable cable length? The limit is defined by the loop resistance; total resistance (including cable and input card impedance) must not exceed (Vs - 12 V) / 0.02 A.

• Can the unit be mounted in any orientation? Yes, the shear-mode sensing element allows for mounting in any orientation relative to the vibration vector.

• How is the output signal calculated? The 4-20 mA output is linearly proportional to the measured RMS velocity within the defined 0-50.8 mm/s range.

• Does the transmitter require periodic calibration? No, the factory-set gain and zero points are permanent; no field adjustments are provided or required.

• How should the shield be handled? The cable shield should be grounded only at the receiving end (PLC/DCS) to prevent ground loops.

• Is the device hot-swappable? As a loop-powered device, disconnecting the transmitter will break the current loop; observe standard site safety protocols for 4-20 mA circuits.

• What happens if the power supply exceeds 30 VDC? Exceeding the maximum excitation voltage may cause internal thermal failure of the current regulation circuitry.

Field Installation Guidelines

Mount the transmitter directly to a clean, flat machine surface using the integral stud. Apply a torque of 20 N·m (177 lbf·in). If using a magnetic base, ensure proper seating without impact loading. Use shielded twisted-pair cable for the 4-20 mA loop. Connect the shield drain wire to the PLC/DCS ground terminal only. Verify the loop power supply provides sufficient voltage headroom for the selected cable length.

Ordering Information

• 177230-02-01-05 Seismic Transmitter
• 4-20 mA loop-powered configuration
• Multiple agency approvals included

Dispatch & Packaging

Dispatch occurs within 3-5 days after payment clearance via DHL / FEDEX / UPS. Each transmitter is sealed in anti-static ESD shielding and foam-packaged to prevent piezoelectric damage during transit.