177230-02-02-CN Bently Nevada 4-20 mA Seismic Transmitter

Bently Nevada 177230-02-02-CN Seismic Transmitter

The Bently Nevada 177230-02-02-CN, also cataloged as the 177230 Seismic Transmitter, converts casing vibration velocity to a 4-20 mA signal. Option 02 provides 0 - 50.8 mm/s (0 - 2.0 in/s) range, 3 Hz to 1 kHz response. CN approvals apply.

Hardware Specifications

Signal Interface and Mounting

The 177230 uses electromagnetic induction, not eddy-current displacement. No -10 VDC gap voltage applies. Shielded twisted-pair cable is required. Ground the shield at the monitor end only. Mount on a flat machined surface with silicone grease to improve high-frequency response. The wide 3 Hz to 1 kHz range captures low to high frequency vibrations for machinery monitoring.

Frequently Asked Questions

Q: Can the transmitter be hot-swapped?
A: No. Disconnecting the loop interrupts the 4-20 mA signal. Remove power or bypass the loop before replacement.

Q: What cable length is supported?
A: Total loop resistance including cable and receiver must stay below the specified load limit for 24 VDC supply. Use shielded twisted-pair.

Q: Is it compatible with 3500 monitor racks?
A: Yes, via a 4-20 mA input module. Direct connection to proximity probe inputs is not supported.

Field Installation Guidelines

1. Mount on a flat machined surface. Tighten stud to specified torque. No washer between base and surface.
2. Apply silicone grease to mounting surface. Avoid air gaps.
3. Route cable away from AC drives (300 mm min) and 24 VDC wiring (150 mm min).
4. Ground shield at monitor end only.
5. Verify loop current with milliammeter before monitor connection. 12 mA = zero vibration.
6. For NPT entries, engage 5 threads minimum. Seal conduit fitting only.