Description
Bently Nevada 126648-02 Isolated Keyphasor I/O Module
The Bently Nevada 126648-02, also cataloged as the 126648-02 Isolated Keyphasor I/O Module, operates as a dedicated hardware component for isolating Keyphasor signals from magnetic pickups or Proximitor sensors within the 3500 monitoring system.
Hardware Specifications
| Parameter |
Specification |
| Model |
126648-02 |
| Brand |
Bently Nevada |
| Origin |
United States |
| Weight |
1.4 kg |
| Dimensions |
5.1 x 20.3 x 33 cm |
| Operating Temp |
Industry standard ambient (0-60 deg C recommended) |
| Power Consumption |
3.2 Watts typical |
| Input Signal |
+5 V to -11 V for isolated operation; compatible with magnetic pickups and Proximitor transducers |
| Input Impedance |
21.8 kΩ minimum |
| Core Function |
Converts proximity/magnetic signals to digital Keyphasor pulses |
| Signal Capacity |
Up to 2 signals per module |
| Minimum Shaft Speed |
200 rpm (passive magnetic pickups) |
Eddy-Current Probe & Rotor Signal Isolation
The module implements eddy-current probe scaling to ensure accurate pulse generation while maintaining a measured gap voltage of -10 VDC tolerance. This configuration reduces signal cross-talk and preserves rotor dynamic data integrity across multiple monitoring channels. For applications requiring Proximitor integration, external power supplies allow full isolation without affecting 3500 monitor module performance. Phase measurement is supported but introduces slightly greater shift compared to non-isolated modules, optimized for shaft speed detection.
Frequently Asked Questions (FAQ)
Q: Can the 126648-02 module operate in parallel with other Keyphasor modules?
A: Yes, the isolated I/O design allows multiple modules to receive the same signal without interference between systems.
Q: What are the input signal limits for magnetic pickups?
A: The module accepts +5 V to -11 V; internal circuitry limits signals beyond this range.
Q: Is external power required for Proximitor compatibility?
A: Yes, an external power supply is necessary to maintain full isolation when using Proximitor sensors.
Field Installation Guidelines
-
Mount the module in standard 3500 racks ensuring proper orientation and clearance for cooling.
-
Route signal wires with shielding connected to system ground to minimize EMI.
-
Keep Keyphasor and proximity sensor cabling separate from high-voltage power lines.
-
Verify input signal polarity and continuity before powering the module.
-
Ensure magnetic pickups meet the minimum rotational speed requirement of 200 rpm for accurate detection.
