The GE / Bently Nevada 3300/20 Dual Thrust Position Monitor provides continuous surveillance of axial thrust bearing position in rotating machinery through real-time measurement of shaft axial displacement. This dual-channel instrument delivers early warning detection of thrust bearing failure, preventing catastrophic operational disruptions and equipment damage. As a core component of the Bently Nevada 3300 monitoring system, it combines precision measurement with flexible signal conditioning to protect critical rotating equipment.
## Technical Specifications
**Measurement Principle:** Gap voltage measurement via proximity probe sensing.
**Full-Scale Range Options:** 25-0-25 mils, 30-0-30 mils, 40-0-40 mils, 50-0-50 mils, 75-0-75 mils, 0.5-0-0.5 mm, 1.0-0-1.0 mm, 2.0-0-2.0 mm, ±25 mils (Option 12).
**Sensitivity:** User-programmable—200 mV/mil (8 V/mm) or 100 mV/mil (4 V/mm).
**Signal Conditioning Accuracy:** ±0.33% of full-scale typical; ±1% maximum at +25°C.
**Measurement Accuracy:** ±1% of full scale.
**Recorder Output Accuracy:**
• 4–20 mA: ±0.7% of signal, ±0.09 mA offset at +25°C
• 1–5 Vdc: ±1.1% of signal, ±10 mV offset at +25°C
• 0 to −10 Vdc: ±1.1% of signal, ±15 mV offset at +25°C
**Alarm Setpoints:** Bi-directional Alert and Danger thresholds, digitally adjustable 0–100% of full-scale. Repeatability within 0.39% of full-scale; LCD resolution ±1.6%.
**Display:** 63-segment LCD per channel; displays error codes and ADJUST mode.
**LED Status Indicators:** Green OK LED per channel (constant ON = normal, OFF = fault or bypassed); 5 Hz flashing indicates stored error codes.
## Key Features
• Dual independent measurement channels for simultaneous thrust position monitoring
• Voting logic support: AND (recommended for thrust position) and OR configurations
• Normal thrust direction programmable per channel—toward or away from probe
• Compatible with 3300, 7200, and 3000 Proximitor sensor systems
• Transducer input options with 100 mV/mil or 200 mV/mil sensitivity
## Typical Applications
Axial position monitoring in large rotating machinery including turbines, compressors, and pumps where thrust bearing wear or failure represents significant operational risk.
## Compatibility & Integration
Integrates with 3300 and 7200 Proximitor Systems (200 mV/mil); 7200 11 mm Proximitor (100 mV/mil); 7200 14 mm and 3300 HTPS Proximitor systems (100 mV/mil); 3000 Proximitor (200 mV/mil); 3300XL NSv and 3300 RAM Proximitor sensors (200 mV/mil). AND voting logic strongly recommended; external implementation required for Quad Relay configurations.
