General

Manufacturer: Bently Nevada (Baker Hughes)

Model: 3500/25 (Enhanced Keyphasor Module)

Type: Half‑height, 2‑channel module

PWA: 149369‑01 (replaces legacy 125792‑01)

Application: Provides keyphasor signals for speed, phase, 1X/2X vector, and tracking filter measurements in 3500 TSI systems

Inputs

Channel Count: 2 independent keyphasor input channels

Sensor Types: Proximity probes (eddy current), magnetic pickups

Signal Voltage Range:

Non‑isolated: +0.8 V to –21.0 V

Isolated: +5 V to –11 V

Input Impedance: Min. 21.8 kΩ per channel

Frequency Range: 0.017 Hz to 20 kHz (1–1,200,000 CPM)

Sensor Power: –24 VDC, max. 40 mA per channel

Outputs

Buffered Keyphasor Outputs: 2 (one per channel)

Output Impedance: Max. 504 Ω

Signal Type: Digital keyphasor pulses (synchronous with shaft mark)

Performance

Phase Accuracy: ±0.1°

Speed Accuracy: ±0.05% of reading

Max Keyphasor Signals per Rack: 4 (2 modules, paired config: up to 8)

Electrical & Power

Power Supply: +5 VDC from 3500 rack backplane

Power Consumption: 3.2 W typical

Environmental

Operating Temperature: –30 °C to +65 °C

Storage Temperature: –40 °C to +85 °C

Humidity: 5%–95% non‑condensing

Mechanical

Dimensions (H × W × D): 241.3 × 12.2 × 99.1 mm (half‑height)

Weight: 0.46 kg (1.01 lb)

Installation: Any half‑height slot in 3500 rack; two modules stack vertically in one slot

Ordering Codes (Example)

3500/25‑02‑01: Standard enhanced keyphasor module, internal terminations

3500/25‑01‑04: Isolated inputs, buffered outputs