Description
3500/50-A01-B00: Product Overview
- This device is a tachometer module within the 3500 Monitoring System, designed for precise measurement of shaft rotational speed and provision of phase reference signals in rotating machinery. In an automation system, it serves as the primary interface for speed/phase sensors (e.g., magnetic pickups, proximity probes), converting raw sensor signals into standardized outputs for machinery protection and control systems (DCS/SIS). The 3500 framework is recognized for its modularity and reliability, and this module enhances it by enabling critical speed monitoring (e.g., overspeed protection) and phase synchronization (e.g., vibration analysis alignment). It supports dual-channel inputs for redundant monitoring of critical assets like turbines or compressors, with outputs compatible with 3500/42M vibration monitors and 3500/92 communication gateways. The A01-B00 configuration denotes 2 independent channels and base functionality for standard industrial applications.
Bently Nevada 3500/50-A01-B00
3500/50-A01-B00: Technical Specifications
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Model Number: 3500/50-A01-B00
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Manufacturer: Bently Nevada
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Product Type: Tachometer Module (Speed/Phase Reference)
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Number of Channels: 2 independent (redundant speed/phase monitoring)
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Input Type: Magnetic pickups (variable reluctance), proximity probes (eddy current), TTL/CMOS digital pulses
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Speed Range: 0-50,000 RPM (0-833 Hz at 60 pulses/rev)
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Output Signals: Pulse train (per channel, proportional to RPM), 4-20mA analog (per channel, linear to speed)
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Phase Reference Accuracy: ±1° (relative to keyphasor signal)
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Supply Voltage: 24V DC (±10%, from 3500 rack power supply)
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Operating Temperature: 0°C to +65°C (rack-mounted)
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Isolation: 500Vrms (channel-to-rack, per IEC 60664-1)
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Dimensions: 119mm (H) x 25mm (W) x 102mm (D) (3500 half-height slot)
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Weight: 0.17kg (rack-mountable)
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Certifications: CE, UL/cUL, ATEX (optional)
Bently Nevada 3500/50-A01-B00
Core Features & Customer Value
Dual-Channel Redundancy: The 2 independent channels allow simultaneous monitoring of a single shaft (e.g., primary + backup sensor) or multiple shafts. For engineers, this eliminates single-point failure risks in critical assets like 500MW steam turbines, where loss of speed data could prevent overspeed protection.
High-Precision Speed Measurement: With a 0-50,000 RPM range and ±0.1% accuracy, the module resolves speed changes as small as 1 RPM. This supports precise control in applications like compressor surge prevention, where maintaining speed within ±2% avoids costly shutdowns.
Phase Reference Synchronization: The module aligns phase data with keyphasor signals (e.g., from 3500/25), enabling accurate vibration orbit plots and rotor dynamic analysis. For predictive maintenance teams, this improves fault diagnosis of imbalance or misalignment.
Seamless 3500 System Integration: Native compatibility with 3500/42M monitors and 3500/92 gateways reduces configuration time. The 4-20mA analog output feeds plant DCS for trending, while pulse outputs trigger protection logic—all via plug-and-play setup in 3500 Configuration Software.
Compact, Low-Power Design: Occupying a half-height slot and drawing 6W nominal power, it minimizes rack space and load on 3500/15 power supplies. This is critical for retrofits in crowded control cabinets.
Typical Applications
This module is deployed in rotating machinery requiring precise speed/phase monitoring. In steam turbines at power plants, it measures rotor speed to trigger overspeed trips (e.g., 3,600 RPM limit for 60Hz generators) and provides phase data for vibration analysis. Centrifugal compressors at refineries use it to monitor suction/discharge speeds, preventing surge via DCS feedback. Gas turbines employ it for startup speed ramping (e.g., 0-3,000 RPM warm-up) and synchronization with the grid. Hydroelectric generators use it for governor control (speed regulation) and phase locking during并网. The dual-channel design is particularly valued in ethylene crackers, where redundant speed signals ensure continuous monitoring of cracked gas compressors.
