177230-01-01-05 Bently Nevada Seismic Transmitter | Original

Bently Nevada 177230-01-01-05 Seismic Transmitter

The 177230-01-01-05 (also cataloged as the 177230 Seismic Transmitter) converts casing vibration into a 4-20 mA loop signal. It houses a piezoelectric sensing element and two-wire transmitter circuit in a sealed IP65 body.

Hardware Specifications

Seismic Signal Characteristics

The 177230 uses seismic velocity sensing, distinct from eddy-current proximity probes. The internal crystal generates charge proportional to casing vibration, conditioned into a 4-20 mA output. Signal integrity depends on shield grounding at the monitoring end only. The two-wire current loop topology suppresses induced voltage noise on long cable runs. Gap voltage validation does not apply to this transmitter. Frequency response is factory-set and not field-adjustable.

Frequently Asked Questions

Q: What is the maximum loop resistance?
A: At 24 VDC, typically 600 ohms. Total cable and receiver resistance must not exceed the limit derived from supply voltage.

Q: Is the 177230-01-01-05 hot-swappable?
A: No. Disconnecting it interrupts the current loop and causes a fault reading. Place the channel in bypass before removal.

Q: Can it work with any 4-20 mA system?
A: Yes, if the receiver supplies 12-30 VDC and accepts 4-20 mA. It does not support HART.

Field Installation Guidelines

Mount directly on the machine casing with a stud or rigid bracket. Ensure flat metal-to-metal contact; avoid paint or gaskets. Route the two-wire cable away from high-voltage conductors. Use twisted-pair shielded cable with the shield terminated only at the monitoring end. For IP65 integrity, use a cable gland with proper thread engagement; NPT threads require a minimum of 5 engaged threads. Verify loop current with a milliammeter before connecting to the monitoring card. Do not exceed -40 deg C to 85 deg C at the mounting location.