Description
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | Bently Nevada 3500/53M 286566-01 |
| Manufacturer | Bently Nevada (a Baker Hughes business) |
| Product Type | Electronic Overspeed Detection Module, single-channel |
| System Platform | 3500 Series Machinery Protection System, 3500/05 System Rack |
| Ordering Reference | 3500/53-AXX-BXX (A: 02 = two-channel system, 03 = three-channel system; B: 00 = none, 01 = CSA/NRTL/C approval) |
| Input Signal | One transducer input per module; +10.0 V to -24.0 V, internally limited; input impedance 20 kΩ |
| Compatible Transducers | 3300 8 mm Proximitor, 3300 16 mm HTPS, 7200 5/8/11/14 mm Proximitor, 3300 RAM Proximitor, passive magnetic pickups |
| Speed Measurement Range | 1 to 99,999 rpm; 1 to 255 events per revolution; maximum input frequency 20 kHz; minimum 0.0167 Hz (proximity) / 3.3 Hz (magnetic pickup) |
| Measurement Accuracy | ±0.1 rpm below 100 rpm; ±1 rpm from 100 to 10,000 rpm; ±0.01% from 10,000 to 99,999 rpm |
| Alarm Setpoints and Response | Under Alert, Over Alert and Danger (Overspeed), adjustable 0–100% of full scale via software; alarm time delay less than 30 ms above 300 Hz |
| Relay Outputs | Four fast-response SPDT (Form C) relays, epoxy sealed, 250 Vrms arc suppressors fitted, switch-selectable normally energized or normally de-energized |
| Relay Contact Ratings | 5 A maximum switched current (resistive); 120 W dc / 600 VA ac; 30 Vdc / 250 Vac maximum; contact life 100,000 operations at 5 A |
| Recorder and Buffered Outputs | +4 to +20 mA proportional to full-scale rpm, 0.3662 µA per bit, ±0.25% error at room temperature, ~100 ms update; front-panel coaxial buffered transducer output, 550 Ω, short-circuit and ESD protected |
| Transducer Power and Consumption | -24 Vdc, 40 mA maximum sensor excitation; 8.0 W typical module power drawn from the 3500 rack |
| Voting Architecture | 2-out-of-2 or 2-out-of-3 (recommended); redundant rack power supplies are mandatory |
| Front Panel Indication | OK, TX/RX, Bypass, Test Mode and Alarm LEDs |
| Environmental Limits | Operating -30°C to +65°C (-22°F to +149°F); storage -40°C to +85°C (-40°F to +185°F); 95% humidity, non-condensing |
| Physical Dimensions and Weight | Monitor module 241.3 mm × 24.4 mm × 241.8 mm, 0.82 kg (1.8 lb); I/O module 241.3 mm × 24.4 mm × 99.1 mm, 0.45 kg (1.0 lb) |
| Rack Space Requirement | One full-height front slot per channel plus one full-height rear slot for the I/O module |
| Compliance and Certification | API 670 and API 612; CE EMC per EN 50081-2 and EN 50082-2; CSA/NRTL/C Class I, Division 2, Groups A–D (approval option 01) |
Main Features and Advantages
API 670 and API 612 compliance by design: The Bently Nevada 3500/53M 286566-01 was developed specifically against the two API standards that govern overspeed protection, which means procurement teams and machinery engineers can build a compliant protection system without adding third-party validation hardware or writing justification documents for a general-purpose tachometer. This compliance is not a marketing label; it shapes the module’s redundancy requirements, its relay behaviour and its diagnostic coverage.
Voting architecture that defeats both missed trips and nuisance trips: A single overspeed channel faces an impossible trade-off — configure it sensitively and a failed probe trips the plant, configure it conservatively and a real overspeed is missed. The Bently Nevada 3500/53M 286566-01 resolves this by working in 2-out-of-2 or, preferably, 2-out-of-3 groups, where a genuine overspeed condition agreed on by two independent channels produces a hard trip while a single faulty channel is outvoted and isolated. Plants gains both safety and availability, which is precisely the balance the 3500 platform is known for.
Sub-30 millisecond response when seconds do not exist: With alarm time delays of less than 30 ms above 300 Hz and four dedicated fast-response relays on board, the module closes its contacts and de-energises the trip circuit while the rotor is still accelerating through the danger band. Every relay is epoxy sealed, protected by 250 Vrms arc suppressors, and selectable for normally energized or normally de-energized operation, so it can be matched to either energise-to-trip or de-energise-to-trip shutdown philosophies.
Transducer flexibility that protects existing field investment: The module accepts signals from 3300 8 mm and 16 mm HTPS Proximitors, the full 7200 series, 3300 RAM probes and passive magnetic pickups, with selectable auto or manual trigger thresholds and adjustable hysteresis from 0.2 to 2.5 V. Existing sensors and existing machine gear or notch wheels can therefore be reused during a retrofit, and the built-in -24 Vdc transducer supply removes the need for separate sensor excitation.
Diagnostics that make protection verifiable: Front-panel OK, TX/RX, Bypass, Test Mode and Alarm LEDs give operators an immediate health read, while Test Mode allows relay logic and trip wiring to be proven without rotating the machine. A buffered coaxial transducer output permits an external tachometer or oscilloscope to be connected for commissioning, and the +4 to +20 mA recorder output feeds live speed and peak speed values to the DCS, PLC or SCADA for trending and post-event analysis.
