EPRO CON021 Eddy Current Preprocessor (User Manual - No Diagram Version) I. Product Overview

CON021 is an eddy current sensor preamplifier of the EPRO brand under Emerson. It is a core signal conditioning component of the MMS6000/AMS6500 TSI system and is specifically designed for the PR6422/PR6423/PR6424/PR6425/PR6426 series of eddy current sensors. It converts the weak signals from the sensors into standard DC voltage signals, which are used for monitoring the shaft vibration, shaft displacement, temperature difference, and phase alignment of rotating machinery.

II. Model Meaning

CON021: Standard Preprocessor (IP20, LEMO connector, non-explosion-proof)

Example of matching models: CON021/916-240 (custom parameters)

III. Compatible Sensors Table

Sensor model: PR6426/010-140

Measurement range: 0 - 4mm

Sensitivity: -7.87V/mm

Linear range: -4 to -20V PR6425/... 0 - 2mm -10V/mm -4 to -20V PR6424/... 0 - 3mm -8V/mm -4 to -20V PR6423/... 0 - 1.5mm -12V/mm -4 to -20V

IV. Technical Specifications

Electrical Specifications

Power Supply: -18 to -30VDC (standard -24VDC, ±10%)

Power Consumption: ≤ 2W

Output Signal: DC voltage (DC) + AC vibration (AC) combined signal

Linear Range: -4 to -20V (corresponding to sensor range)

Reference Voltage: -12V (optimal working point, gap approximately 5.5mm)

Frequency Response: 0 to 10kHz (-3dB)

Response Time: ≤ 15μs

Accuracy: Linear Error ≤ ±1% FS; Temperature Drift ≤ 0.05%/℃

Protection: Open Circuit / Short Circuit / Reverse Polarity Protection

Physical and Environmental

Protection Grade: IP20 (installed in control cabinet)

Connection Method: Sensor end LEMO plug; Power / Output end screw terminals

Operating Temperature: -30℃ to +100℃

Weight: Approximately 0.6kg

V. Wiring Definitions (Terminal Block) Table

Terminal Identification Function

1 -24V Power negative pole (-18 to -30 VDC)

2 GND Power ground (0V)

3 OUT Signal output (-1 to -22 V)

4 COM Signal ground (separated from GND)

Six, Installation and Debugging

Mechanical Installation

Location: Inside the control cabinet, away from strong electromagnetic interference (frequency converter, motor)

Fixing: 4 M5 screws for panel installation

Spacing: ≥20mm from other equipment, good ventilation

Sensor Connection

Cable: Special double-shielded coaxial cable (≤100m)

Plug: LEMO plug locked in place to avoid loosening

Gap Setting: 5.5mm (reference voltage -12V, optimal linear point)

Power On Debugging

Power Supply: Confirm -24VDC (±10%), polarity correct

Gap Voltage Measurement:

Normal Value: -10 to -12V (gap 5.5mm, midpoint of the linear zone)

Close to 0V: Sensor open circuit / short circuit / plug loosening

Close to -22V: Sensor short circuit / gap too large

Signal Verification: When rotating the shaft, AC component changes with vibration, frequency consistent with speed / fault characteristics

Seven, Fault Troubleshooting

No output signal (OUT ≈ 0V)

Sensor: Coil resistance 3 to 15Ω, insulation resistance >100MΩ

Cable: Break / short circuit / shielding layer damaged

Plug: LEMO not locked / pin oxidation

Preprocessor: Power supply abnormal or internal circuit damage

High signal noise / fluctuation

Interference: Cable close to power line / frequency converter, double-ended grounding of shielding layer (should be single-point grounding)

Gap: Deviation from 5.5mm, beyond the linear range

Target Surface: Material not soft magnetic steel, rough / dirty

Output Saturation (OUT ≈ -22V)

Gap too large: Probe away from target surface, beyond measurement range

Sensor short circuit: Coil connected to casing

Eight, Accessories and Selection

Standard Accessories: CON021 + PR6426/010-140 + MMS6312 (rotation speed) / MMS6110 (vibration)

Cable: Double-shielded coaxial cable (such as RG223), length according to on-site requirements

Attachments: LEMO plug, terminal connector, fixing bracket