Description
Product Core Brief
- Model: 3500/50 (Part: 133388-02)
- Brand: Bently Nevada
- Series: 3500 Machinery Protection System
- Core Function: Determines shaft speed, rotor acceleration, and rotor direction.
- Product Type: 2-Channel Tachometer Monitor Module
- Key Specs: Dual Sensor Input | ±20 RPM/Min Accuracy | 5.8W Power
- Condition: New Original (New Surplus)
BENTLY 3500/50 133388-02
Product Introduction
BENTLY 3500/50 133388-02 is a 2-channel tachometer monitor module designed for the Bently Nevada 3500 Machinery Protection System. It accepts inputs from proximity probes or magnetic sensors to accurately determine machine rotational speed.
This module continuously compares the measured speed, acceleration, and directional parameters against user-programmable alarm setpoints. It is highly configurable via the 3500 Rack Configuration Software to support multiple monitoring functions, including speed monitoring, zero-speed notification, reverse rotation detection, and rotor acceleration alarms. When configured limits are violated, the module generates alarms to protect the machinery.
Key Technical Specifications
- Module Type: 2-Channel Tachometer Monitor
- Input Signal Range: +10.0 V to -24.0 V
- Input Impedance: 20 kΩ (Standard), 40 kΩ (TMR), 7.15 kΩ (Internal Barrier)
- Output Impedance: 550 Ω
- Speed Accuracy: ± 20 RPM/Min
- Typical Power Consumption: 5.8 Watts
- Indicators: OK LED, TX/RX LED, Bypass LED
- Software Requirements: 3500 Rack Configuration Software
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Trace source via serial number. Inspect front panel connectors and rear Euro-connector for physical damage.
- Visual Inspection: Verify OK, TX/RX, and Bypass LED indicators and module seating alignment.
- Live Functional Test: Install in rack. Verify “OK” LED illuminates and communication with RIM/TDI is established.
- Signal Path Test: Inject simulated tachometer pulse signal. Verify accurate RPM calculation and alarm triggering in software.
- Final QC & Packaging: Seal in anti-static bag. Apply QC Passed label with date.
BENTLY 3500/50 133388-02
Replacement Pitfall Guide
❗ Factory Unconfigured: The 3500/50 module ships from the factory unconfigured. It must be inserted into a 3500 frame and programmed using the 3500 Rack Configuration Software to execute the required monitoring functions.
❗ Sensor Compatibility: This module accepts inputs from eddy current proximity probes (e.g., 3300 XL, 7200 series) or magnetic pickups. Ensure the selected sensor type matches the module’s input configuration.
❗ Software Configuration Options: The module supports multiple distinct configurations. Ensure the correct function is selected during setup: Speed/Setpoint Alarms, Speed Band Alarms, Zero Speed Notification, Reverse Rotation Notification, or Rotor Acceleration Alarms.
❗ Bypass Mode: The Bypass LED indicates the module is in bypass mode. If illuminated during normal operation, check the software configuration and verify that no maintenance bypass commands are active.
❗ TMR Impedance: If used in a Triple Modular Redundancy (TMR) configuration, note that the input impedance changes to 40 kΩ. Ensure the I/O module suffix matches your system’s redundancy and termination requirements.
Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
- 3500/50 133388-02 → 3500/53 : Alternative — Use 3500/53 for dedicated electronic overspeed protection (2oo3 voting)
- 3500/50 133388-02 → 3500/22M : Complementary — Requires TDI module for rack communication
- 3500/50 133388-02 → 3300 XL / 7200 Probes : Compatible — Standard eddy current and magnetic speed sensors
Benchmarks:
- Alarm Response Time: < 50 ms (typical)
- Input Signal Clipping: Signals outside +10.0 V to -24.0 V range are internally limited
