Bently Nevada 3500/53 133388-01 Overspeed Detection Module

Description

The Bently Nevada 3500/53 133388-01 is a high-reliability, fast-response, redundant tachometer module designed specifically for machinery overspeed protection within the 3500 Series Machinery Detection System. It meets the rigorous requirements of American Petroleum Institute (API) Standards 670 and 612 for overspeed protection.

The 3500/53 module accepts input signals from proximity probe transducers or magnetic pickups to continuously monitor rotational speed. Multiple modules can be combined in a 3500 rack featuring redundant power supplies to form a 2-out-of-2 or a 2-out-of-3 voting logic system. The module provides proportional current outputs for recorders, buffered transducer outputs for diagnostics, and onboard single-pole double-throw (SPDT) relays to drive emergency shutdown systems.

Features

• Supports 2-out-of-2 or 2-out-of-3 redundant voting configurations.
• Compatible with proximity probes and passive magnetic pickups.
• Provides both auto-threshold and manual-threshold transducer conditioning.
• Integrated single-pole double-throw (SPDT) relays with selectable normally energized or normally de-energized operation.
• Front panel LED indicators for module status, communication, bypass, test mode, and alarms.
• Dedicated front-panel coaxial connector for buffered transducer output.
• Software-configurable alarm setpoints for Under Alert, Over Alert, and Danger (Overspeed).

Applications

• Steam turbines
• Gas turbines
• Turbo-compressors
• High-speed expanders
• Large industrial pumps and fans

Technical Specifications

Compliance and Certifications

• EMC Directives: EN50081-2 (Radiated/Conducted Emissions EN 55011 Class A), EN50082-2 (ESD EN 61000-4-2, Radiated ENV 50140, Conducted ENV 50141, Fast Transient EN 61000-4-4, Surge EN 61000-4-5, Magnetic Field EN 61000-4-8, Voltage Dip EN 61000-4-11, Radio Telephone ENV 50204)
• Low Voltage Directives: EN 61010-1 Safety Requirements
• Hazardous Area Approvals: CSA/NRTL/C, Class I, Div 2, Groups A, B, C, D, T4 @ Ta = -20 Celsius to +65 Celsius (Certification Number: CSA 150268-1002151)

Installation Guidelines

• Rack Requirements: The overspeed detection system must be installed in a 3500 rack equipped with redundant power supplies to ensure continuous operation.
• Voting Logic Configuration: For optimal protection and compliance with industry safety standards, combine multiple modules to establish a 2-out-of-3 voting scheme.
• Wiring and Shielding: Ensure transducer cables are properly shielded and grounded according to standard Bently Nevada practices to mitigate EMI/RFI interference.
• Transducer Threshold Selection: Use the Auto Threshold setting for standard speed ranges above 1 rpm. For specialized low-speed applications or weak signals, configure the Manual Threshold via software.
• Relay Configuration: Verify the hardware switch selection for Normally Energized (NE) or Normally De-energized (ND) matches the logic requirements of the emergency shutdown system before commissioning.

FAQ

What is the primary function of this module?

The module provides high-speed, redundant machinery overspeed detection and protection for critical industrial rotating assets.

Which API standards does this module comply with?

It is designed to meet the specific overspeed protection requirements outlined in API Standards 670 and 612.

Can this module handle inputs from magnetic pickups?

Yes, it accepts signals from passive magnetic pickups as well as standard proximity probe transducers.

What is the maximum speed range supported by the module?

The module supports a maximum full-scale range of 99,999 rpm and an input frequency up to 20 kHz.

What voting logic is recommended for the overspeed system?

A 2-out-of-3 voting system configuration is highly recommended for optimal reliability and fault tolerance.

What is the typical response time for an alarm?

The alarm time delay is less than 30 ms when operating above an input frequency of 300 Hz.

Does the module provide an analog trend output?

Yes, it provides a +4 to +20 mA recorder output proportional to the configured full-scale rpm range.

What happens if the recorder output suffers a short circuit?

The module operation remains completely unaffected by short circuits on the recorder output line.

What are the threshold configuration options for speed detection?

It features Auto Threshold for signals above 0.0167 Hz and a software-adjustable Manual Threshold from +9.9 Vdc to -23.9 Vdc.

What type of internal relays are used?

The module utilizes epoxy-sealed single-pole double-throw relays equipped with standard 250 Vrms arc suppressors.

Can the relay states be modified?

Each relay is switch-selectable to operate as either Normally Energized or Normally De-energized.

What does a solid light on the Bypass LED indicate?

The Bypass LED indicates that the overspeed module has been placed into its bypass mode, suspending active trip outputs.

Is this module safe for deployment in hazardous areas?

Yes, it carries CSA/NRTL/C approval for Class I, Division 2, Groups A, B, C, and D hazardous environments.