Key Technical Specifications
| Parameter | Detail |
|---|---|
| Part Number | 133388-01 |
| Module Type | 3500/53 Overspeed Detection Module |
| Application | Redundant overspeed protection for turbines, compressors, generators |
| System Compatibility | Bently Nevada 3500 rack |
| Input Signal | Proximitor or magnetic pickup, +10.0 V to −24.0 V |
| Input Impedance | 20 kΩ |
| Speed Range | Up to 99,999 rpm |
| Max Input Frequency | 20 kHz |
| Events per Revolution | 1 to 255 |
| Voting Logic | 2oo2 or 2oo3 (2oo3 recommended) |
| Relay Output | SPDT, 5 A max, 30 VDC / 250 VAC |
| Recorder Output | +4 to +20 mA proportional to rpm |
| Power Consumption | Approx. 8.0 W typical |
| Operating Temperature | −30 °C to +65 °C |
| Condition | New Surplus or Refurbished (Tested), subject to stock |
| Warranty | 12 months unless otherwise stated |
Product Introduction
Bently Nevada 3500/53 133388-01 is an electronic overspeed detection module for the 3500 machinery protection system. It accepts proximitor or magnetic pickup signals to monitor shaft speed and drive alarm or trip relays when configured setpoints are exceeded.It is designed for API 670 / API 612-style overspeed protection and supports 2oo2 or 2oo3 voting. Typical use includes steam turbines, gas turbines, compressors, and generators where fast, redundant speed monitoring is required. Full-scale range reaches 99,999 rpm with a 20 kHz maximum input frequency.
Installation & Configuration Guide
Preparation (10 min)
- Record rack ID, slot position, and existing alarm setpoints.
- Photograph the label, revision, LED status, and cable connections.
- Confirm whether the module is part of a 2oo2 or 2oo3 group.
- Verify rack firmware and configuration software compatibility.
Removal (5–10 min)
- Follow site lockout/tagout rules before working on protection systems.
- Do not remove overspeed modules during live operation unless approved.
- Label sensor cables, relay outputs, and recorder outputs.
- Remove the module without forcing the backplane connector.
Installation (10 min)
- Install into an adjacent slot if used in a multi-module voting group.
- Only one overspeed group is allowed per 3500 rack.
- Reconnect sensor, relay, and recorder wiring per saved labels.
- Verify redundant 3500/15 power supplies are present and healthy.
Power-On & Test (10 min)
- Confirm OK, TX/RX, Bypass, Test Mode, and Alarm LEDs behave as expected.
- Download or verify configuration from the 3500 rack software.
- Simulate speed input to validate alert, danger, and trip setpoints.
- Test relay operation and recorder output before returning to service.
Troubleshooting Quick Reference
| Symptom | Likely Cause | First Action |
|---|---|---|
| OK LED off | No power or failed module | Check rack power and slot seating |
| TX/RX LED inactive | Backplane communication fault | Reseat module; verify rack interface |
| False overspeed alarm | Sensor noise or wrong threshold | Check sensor gap, cable shield, and trigger level |
| No trip on test | Wrong voting logic or bypass active | Verify 2oo2/2oo3 group and bypass state |
| Recorder output incorrect | Scaling mismatch | Confirm full-scale rpm and 4–20 mA mapping |
| Module not recognized | Firmware or revision mismatch | Compare rack firmware and module revision |
Dimensions, Mounting & Wiring Notes
- Mounting: 3500 Series 19-inch rack, monitor slots 2–15.
- Grouping: Overspeed modules must be installed in adjacent slots.
- Sensor input: Proximitor or magnetic pickup; input range +10.0 V to −24.0 V.
- Relay output: SPDT dry contacts; verify NO/NC wiring before energizing trip circuits.
- Recorder output: +4 to +20 mA, 0–600 Ω load.
- ESD: Handle as a static-sensitive assembly.
FAQ
Is 133388-01 the same as 133396-01?
No. 133388-01 is the 3500/53 overspeed detection module. 133396-01 is the associated overspeed I/O module. They are not interchangeable.Can I install just one 3500/53 module?
A single module can operate, but overspeed protection systems typically use two or three modules for 2oo2 or 2oo3 voting. Three modules are preferred for higher reliability.I replaced the module but the rack still shows a fault. What should I check?
Check slot position, group configuration, firmware compatibility, sensor input, and whether the module is in bypass or test mode. Also confirm the configuration was downloaded correctly.Does this module replace a 3500/50 or 3500/54?
Not automatically. 3500/50, 3500/53, and 3500/54 serve different overspeed and protection roles. Replacement requires configuration and hardware verification.Is this part still produced by Bently Nevada?
It is generally treated as a legacy/discontinued spare. Supply depends on surplus or tested inventory. Confirm condition and revision before ordering.Do you provide a test report?
Yes, when testing is performed. Reports cover power-up, communication, LED status, input simulation, relay response, and recorder output. Function is verified under test conditions only.
