Description
Application Scenarios
On a 300 MW steam turbine at a combined-cycle power plant, the high-pressure rotor operates on fluid-film bearings where even minor shaft misalignment can escalate into bearing wipe and forced outage. The 3300/16-13-01-01-00-00-00 addresses this by simultaneously monitoring X and Y radial vibration probes at each bearing, calculating peak-to-peak vibration amplitude and average shaft position. When a gradual increase in gap voltage indicates the rotor drifting toward a bearing surface, the monitor’s Alert relay trips a DCS alarm before the vibration reaches Danger level. This early-warning capability allows operators to adjust steam admission or schedule a controlled shutdown during the next planned outage window—rather than facing an unplanned trip that costs hundreds of thousands of dollars in lost generation and repair labor.
Parameter
| Parameter | Value/Description |
|---|---|
| Product Model | 3300/16-13-01-01-00-00-00 |
| Manufacturer | Bently Nevada |
| Product Category | Dual Vibration XY/Gap Monitor Module |
| System Platform | Bently Nevada 3300 Machinery Protection System |
| Input Channels | 2 independent proximity probe inputs |
| Transducer Compatibility | 3300 8 mm, 3300 XL 8 mm, 7200 5 mm and 8 mm Proximitor systems |
| Input Sensitivity | 100 mV/mil (4 V/mm) or 200 mV/mil (8 V/mm), user-programmable |
| Input Impedance | 10 kΩ nominal |
| Full Scale Range | 0–200 µm peak-to-peak (metric scale) |
| Frequency Response | 4–4,000 Hz (240–240,000 cpm) or 1–600 Hz (60–36,000 cpm), selectable |
| Recorder Outputs | +4 to +20 mA, 0 to -10 Vdc, or +1 to +5 Vdc (per channel) |
| Alarm Outputs | Dual epoxy-sealed Alert and Danger relay contacts |
| Power Consumption | 2 W nominal (rack-powered) |
| Operating Temperature | 0°C to +65°C |
| Mounting | Standard 3300 Series rack slot |
Technical Principles and Innovative Values
Innovation Point 1 — Dual-Channel XY Vibration and Gap in One Module: The 3300/16-13-01-01-00-00-00 processes two independent proximity probe signals simultaneously, measuring radial vibration in orthogonal X and Y directions while also deriving average shaft position. This dual-function capability eliminates the need for separate vibration and position monitors at each bearing, reducing rack space and wiring complexity in machinery protection cabinets .
Innovation Point 2 — Supersedes 3300/15 with Enhanced Gap Alarms: Unlike its predecessor the 3300/15 Dual Radial Vibration Monitor, the 3300/16-13-01-01-00-00-00 provides radial position gap alarms in addition to vibration alarms. This means the module can alert operators not only when shaft vibration exceeds safe limits but also when the rotor’s average position drifts too close to a bearing surface—a precursor condition that vibration monitoring alone might miss until damage has already begun .
Innovation Point 3 — OK Circuit for Probe Fault Detection: The module includes an OK circuit that continuously monitors probe and wiring integrity. If a proximity probe fails or its signal cable is damaged, the 3300/16-13-01-01-00-00-00 flags the fault rather than allowing an invalid signal to be interpreted as normal operation. This diagnostic function prevents silent failures that could leave machinery unprotected .
Innovation Point 4 — Field-Selectable Frequency Response: The module supports two frequency response ranges: 4–4,000 Hz for standard radial vibration monitoring and 1–600 Hz for applications requiring lower-frequency response, such as shaft runout or slow-roll monitoring during turbine startup and coast-down .
