Description
Product Core Brief
- Model: 3500/25 125792-01 (Legacy PWA)
- Brand: BENTLY NEVADA
- Series: 3500 Machinery Protection System
- Core Function: Converts proximity/magnetic sensor signals into digital keyphasor timing pulses.
- Product Type: Enhanced Keyphasor Module
- Key Specs: Half-Height | Dual Channel | 1 to 1,200,000 RPM Input Range
- Condition: New Original (New Surplus)
BENTLY 3500/25 125792-01
Product Introduction
The BENTLY 3500/25 125792-01 is an Enhanced Keyphasor Module designed for the 3500 Machinery Protection System. It acts as a half-height, dual-channel module that receives input signals from eddy current (proximity) or electromagnetic (magnetic pickup) sensors. It converts these raw signals into precise digital keyphasor pulses, indicating the exact moment a keyway or gear tooth passes the sensor.
This timing reference is critical for 3500 monitor modules and external diagnostic equipment to measure vector parameters such as 1X amplitude, phase angle, and shaft speed. Note: The specific PWA board number 125792-01 is a legacy version that has been completely replaced by the newer, fully backward-compatible PWA 149369-01. New orders will typically receive the upgraded 149369-01 module.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Module Type | Enhanced Keyphasor (Dual Channel) |
| Legacy PWA Board | 125792-01 (Replaced by 149369-01) |
| Input Sensors | Eddy Current / Electromagnetic (Magnetic Pickup) |
| Input RPM Range | 1 to 1,200,000 RPM (up to 20 kHz) |
| Output RPM Range | 1 to 99,999 RPM |
| Power Consumption | 3.2 Watts (Typical) |
| Sensor Power | -24 Vdc, 40 mA max per channel |
| Installation | Half-Height Front Slot |
| Compliance | API 670, CSA/NRTL/C |
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: We check source traceability and verify serial numbers against anti-counterfeit databases. Visual inspection confirms no physical damage, bent pins, or connector corrosion.
- Live Functional Test: Power-on self-checks validate basic operation. We run continuous load tests exceeding 24 hours with temperature logging to ensure stability.
- Electrical Parameter Test: Insulation resistance is verified using a 500 V Megger, requiring >10 MΩ. Ground continuity is also strictly checked.
- Firmware Verification: We read and record internal firmware versions. DIP switch and jumper settings are photographed for future reference.
- Final QC & Packaging: The unit is sealed in an anti-static bag. A QC Passed label with the inspection date is applied before shipping.
BENTLY 3500/25 125792-01
Replacement Pitfall Guide
❗ Legacy PWA Confusion: The 125792-01 is no longer manufactured. It has been fully replaced by the enhanced PWA 149369-01. The new module is completely backward compatible in form, fit, and function, and can be directly inserted into existing 3500 racks.
❗ TMR Redundancy Requirements: If your system utilizes Triple Modular Redundancy (TMR) and requires a system-wide keyphasor input, you must install two keyphasor modules. They operate in parallel to provide primary and secondary keyphasor signals to the rest of the rack.
❗ Isolated vs. Non-Isolated I/O: Verify your I/O module type. Isolated Keyphasor I/O modules are designed primarily for speed measurement rather than precise phase measurement. Using an isolated I/O module for phase measurement will introduce a slightly higher phase drift compared to non-isolated versions.
❗ Magnetic Pickup RPM Limit: If using passive electromagnetic sensors, ensure the machine’s minimum operating speed exceeds 200 RPM (3.3 Hz), as these sensors cannot generate sufficient voltage below this threshold.
❗ ESD Damage: Use an anti-static mat during installation. Dry environments significantly increase electrostatic discharge risks to sensitive electronics.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
- 3500/25 125792-01 → 3500/25 149369-01 : Direct — Legacy PWA replaced by Enhanced PWA (100% backward compatible)
- 3500/25 125792-01 → 3500/22M : Companion — TDI Module for data communication
- 3500/25 125792-01 → 3500/40M / 3500/42M : Companion — M-Series Monitors utilizing keyphasor for vector analysis
- Max Keyphasors per Rack: Up to 4 standard signals (or 8 in paired configuration)
Need the matching 125800-01 (Non-Isolated) or 125800-02 (Isolated) Keyphasor I/O backplane module to complete this assembly? I can verify the exact wiring and phase-drift requirements for your turbine or compressor.
