Bently Nevada 286566-01 Overspeed Detection Module

Technical Specifications

Parameter	Details
Product Type	Overspeed Detection Module
Compatibility	Bently Nevada 3500 Series Monitoring System
Number of Channels	3 independent channels
Input Type	Proximity probe or magnetic pickup (MPU)
Input Voltage Range	–0.8 V to –21.0 V (proximity probe), 100 mV to 30 V (MPU)
Frequency Range	0.5 Hz to 20 kHz
Measurement Accuracy	±0.5 % of reading
Response Time	50 ms typical (alarm relay)
Overspeed Trip Setting	User-configurable (1 to 100,000 RPM)
Alarm Outputs	3 dedicated relay outputs (form C)
Communication Protocol	Modbus RTU, Modbus TCP/IP
Dimensions (H x W x D)	241 mm x 48 mm x 254 mm
Weight	1.6 kg
Power Supply	24 VDC nominal (18 VDC to 32 VDC)
Power Consumption	10 W typical
Operating Temperature	–20 °C to +65 °C
Storage Temperature	–40 °C to +85 °C
Protection Class	IP20
Certifications	CE, CSA, ATEX, IEC 61508 (SIL 2)

Triply Redundant Speed Monitoring

The 286566-01 overspeed detection module provides three independent channels for critical speed monitoring in high-value rotating machinery. This module accepts inputs from proximity probes or magnetic pickups, covering a frequency range from 0.5 Hz to 20 kHz. The three channels operate in parallel, using a 2-out-of-3 voting logic for trip decisions, which effectively eliminates false trips while ensuring reliable overspeed protection. Such triple modular redundancy makes this module ideal for gas turbines, steam turbines, and large compressors.

Precision and Response Characteristics

The 286566-01 achieves speed measurement accuracy of ±0.5 % of reading, delivering reliable data for critical trip decisions. The module responds to overspeed conditions within 50 ms from signal detection to relay activation, providing rapid protection against catastrophic overspeed events. Users can configure overspeed trip setpoints individually per channel, enabling flexible protection strategies across different machine operating regimes.

Alarm and Shutdown Logic

Each channel on the 286566-01 includes a dedicated form C relay output for alarm or shutdown signaling. The module’s voting logic determines a trip condition when at least two of the three channels exceed their configured setpoints. Additionally, the unit continuously performs self-diagnostics, verifying probe health and internal circuit functionality to maintain system integrity.

System Integration and Mounting

Weighing 1.6 kg and measuring 241 mm x 48 mm x 254 mm, the 286566-01 occupies one full-height slot within the 3500 series rack. The module draws 10 W from a 24 VDC supply and connects to the 3500 backplane for seamless data exchange with other monitoring modules. Users can access speed data, alarm status, and diagnostic logs via Modbus RTU or TCP/IP interfaces, enabling remote monitoring and predictive maintenance.