Description

Product Description

The 3500/53 Overspeed Protection Module (134611-01) is engineered for high-reliability rotational safety control in critical machinery environments. It is deployed within the Bently Nevada 3500 platform to deliver independent overspeed detection, redundant speed evaluation, and direct trip actuation for turbine and compressor protection systems.

The module is designed to operate as a dedicated safety layer, executing fast response logic when rotational speed exceeds defined thresholds.

Protection and Logic Architecture

This module implements dual-channel safety processing with independent evaluation paths:

• Two isolated speed measurement channels

• Primary overspeed shutdown function

• Secondary backup overspeed verification path

• Configurable voting logic:

• 1-out-of-2 (1oo2) trip logic

• 2-out-of-2 (2oo2) trip logic for stricter validation

• Fail-safe design for turbine trip circuit integration

The architecture is intended to minimize false trips while maintaining deterministic shutdown behavior under fault conditions.

Input Characteristics

• Two independent measurement channels

• Sensor compatibility:

• Eddy current proximity probes (preferred for full dynamic range)

• Magnetic pickups (suitable for high-speed applications, reduced low-speed fidelity)

• Input voltage range: +10 V to –24 V DC

• Input impedance: 20 kΩ

• Frequency response: up to 20 kHz depending on transducer selection

• Low-speed detection:

• Proximity probes support near-zero operation

• Magnetic pickups limited at low rotational speeds

Trip and Output Functions

• Dual high-speed, normally energized trip relays

• Direct interface for turbine trip solenoid circuits

• Independent relay outputs for redundancy

• Front-panel status indicators:

• System OK

• Communication activity (TX/RX)

• Bypass condition

• Active trip status

Additional outputs include:

• Buffered speed signal per channel

• Conditioned Keyphasor-style reference output to rack backplane

Performance Characteristics

• Overspeed trip response time: typically < 40 ms (configuration dependent)

• Speed measurement accuracy: ±0.1% of full-scale range

• Measurement repeatability: ±0.05%

These values support deterministic shutdown performance in high-energy rotating equipment.

Electrical and Environmental Data

• Typical power consumption: 6.0 W

• Operating temperature range: –30 °C to +65 °C

• Relative humidity: up to 95% non-condensing

• Compliance and certification:

• API 670 compliant architecture

• CE and CSA certified

• SIL-2 capable when installed per system requirements

Application Areas

• Steam turbine overspeed protection

• Gas turbine safety shutdown systems

• Industrial compressor protection

• Turboexpander monitoring systems

• High-speed rotating machinery safety loops

FAQ

Q1: Is this module suitable for safety shutdown applications?
Yes, it is designed specifically for overspeed trip functions in turbine safety systems.

Q2: Can it operate in redundant voting configurations?
Yes, it supports both 1oo2 and 2oo2 voting logic schemes.

Q3: Does it require proximity probes?
Proximity probes are recommended for full-range performance, especially near zero speed detection.

Specifications

• Brand: Bently Nevada

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems