EPRO pr9268 / 017-100 Electrodynamic Velocity Sensor

The Emerson PR9268/017-100, also cataloged as the PR9268 Electrodynamic Velocity Sensor, operates as a dedicated hardware component for absolute bearing housing vibration measurement within MMS6000 machinery protection systems. The seismic sensor converts mechanical structural vibration velocity directly into an proportional electrical AC millivolt signal without requiring external power amplification.

Hardware Specifications

4-20 mA HART Loop Protocol and DCS Connectivity

The PR9268/017-100 utilizes a moving-coil electrodynamic assembly to generate self-induced voltage outputs proportional to dynamic velocity. Signal conditioning cards receive the high-impedance coil signal across a 1723 ohm internal resistance path, converting raw AC millivolt data into 4-20 mA HART loop protocol outputs for continuous process control integration. Channel-to-channel isolation on the receiving monitor prevents high-voltage spikes and ground loops from corrupting critical vibration telemetry. Integrated signal routing delivers calibrated dynamic velocity profiles directly to Emerson DeltaV and Ovation DCS architectures for automated trip execution and predictive asset monitoring.

Frequently Asked Questions

Q: Does the PR9268/017-100 velocity sensor require an external power supply to operate?

A: No, the sensor uses an internal electrodynamic coil and permanent magnet assembly that self-generates an AC millivolt voltage proportional to vibration velocity.

Q: How does transverse acceleration affect the measurement accuracy of the sensor?

A: Transverse sensitivity is rated at < 0.1 at 80 Hz, minimizing measurement cross-talk from orthogonal axis vibration during continuous operation.

Field Installation Guidelines

1. Mount the velocity sensor rigidly on the machine bearing housing using a threaded mounting stud to ensure complete mechanical energy transfer.
2. Route twisted-pair shielded signal cabling through dedicated metallic conduits separated from high-voltage AC power lines.
3. Connect signal cable shielding strictly to the cabinet instrument ground point (single-point ground) to prevent ground loop noise injection.
4. Verify that physical shaft or casing vibration does not exceed the maximum continuous acceleration limit of 10g (98.1 m/s2) peak-peak.
5. Ensure threaded mounting connections are torqued to specified field ratings to avoid resonance shifts or mechanical loosening during high-vibration events.