Description
Processing phase reference signals within the Bently Nevada 3500 Machinery Protection System is executed by the 3500/25-02-01-00 module. This half-height, four-channel Enhanced Keyphasor Module provides once-per-turn tachometer and phase reference measurements to monitor shaft rotational speed and phase vector parameters. It accepts input signals from proximity probes and magnetic pickups, converting these raw pulses into digital Keyphasor signals used by other monitor modules across the 3500 backplane.
The system configuration of this specific model includes two half-height, 2-channel Keyphasor cards (totaling 4 channels) paired with an internal termination I/O module. This setup handles phase measurement, speed calculation, and tracking filter coordination, enabling diagnostic software such as System 1 to correlate vibration and process data with shaft position.
Features
- Provides multi-channel speed and phase measurements across four total channels.
- Accepts input signals from magnetic pickups, proximity sensors, and optical transducers.
- Internal termination I/O module design eliminates the need for external terminal blocks.
- Supports redundant Keyphasor configuration setups to maintain protection in critical applications.
- Configurable via the 3500 Rack Configuration Software for specific transducer thresholds and hysteresis.
- Transmits phase reference signals digitally across the backplane to all adjacent monitor modules.
Applications
- Steam, gas, and hydro turbine speed and phase monitoring.
- Industrial compressor and expander diagnostics.
- High-speed gearbox and pump phase vector analysis.
- Power generation and petrochemical rotating machinery protection.
Technical Specifications
| Manufacturer |
Bently Nevada |
| Part Number |
3500/25-02-01-00 |
| Series |
3500 Machinery Protection System |
| Module Type |
Enhanced Keyphasor Module |
| Channel Count Option (-02) |
Two half-height, 2-channel Keyphasor cards (4 channels total) |
| I/O Module Option (-01) |
Internal Terminations I/O Module |
| Agency Approval Option (-00) |
None required |
| Input Signal Range |
-0.8 V to -26.0 V (Proximitor sensor) or +1.0 V to +12.0 V (Magnetic pickup) |
| Power Consumption |
3.2 Watts (typical) |
| Operating Temperature |
-30 degC to +65 degC |
| Storage Temperature |
-40 degC to +85 degC |
| Humidity |
95% non-condensing relative humidity |
| Approximate Shipping Weight |
2.0 kg |
Connections and Interfaces
| Terminal Name |
Function Pinout Description |
| KPH 1 / KPH 2 / KPH 3 / KPH 4 |
Signal input from Keyphasor transducers |
| COM |
Common return path for transducers |
| -24 Vdc |
Power supply output for active transducers |
| SHLD |
Shield terminal for field wiring termination |
Installation Guidelines
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Slot Placement: Install only in designated half-height slot positions within the 3500 rack system.
-
Wiring: Use high-quality twisted-shielded cabling for all transducer connections to prevent electromagnetic noise from causing false speed readings.
-
Grounding: Ensure the shield is grounded at the rack end only (the SHLD terminal) to avoid ground loops.
-
Hot-Swapping: Observe proper electrostatic discharge (ESD) and safety procedures if inserting or removing the module while the rack is powered.