Keyphasor Module – Functional Description

Functional Purpose

This module is a half-height, dual-channel unit designed to provide key phase signals to the monitoring modules within the 3500 rack system. It receives input signals from proximity probes or magnetic pickups, converting these signals into digital key phase outputs that indicate when the key phase markings on the rotating shaft align with the key phase sensor.

Technical Specifications

Input Signal Range:

Non-isolated I/O modules: –0.8 V to –21.0 V

Isolated I/O modules: +5 V to –11 V
The module includes internal amplitude limiting to ensure the signal remains within the specified range.

Environmental Limitations:

Operating Temperature:

With standard Keyphasor I/O modules (non–barrier): –30 °C to +65 °C

With Keyphasor I/O modules containing internal barriers: 0 °C to +65 °C

Storage Temperature: –40 °C to +85 °C

Relative Humidity: Up to 95%, non-condensing

Product Features

Compared with earlier designs, this module provides enhanced key signal processing capabilities while maintaining full downward compatibility with existing Keyphasor modules in terms of appearance, installation, and function—making it suitable for both new and legacy 3500 systems.

Additional features include:

Event signal generation per revolution from multiple event input terminals.

On-site firmware upgrade capability for improved serviceability.

Support for asset management data to enhance system diagnostics and monitoring.

System Configuration

The 3500 Machinery Protection System supports:

Up to four key phase signals in a standard configuration.

Up to eight key phase signals in a paired configuration.

For Triple Modular Redundancy (TMR) applications requiring system keying inputs, the 3500 system should employ two Keyphasor modules operating in parallel, providing primary and secondary keying signals to other modules in the rack to ensure system reliability and redundancy.