1. General Information

• Manufacturer: Bently Nevada (Baker Hughes)

• Model Number: 3500/53

• Spare Part Number: 133396-01

• Product Name: Electronic Overspeed Detection Module

• Series: 3500 Machinery Protection System

• Module Type: Full‑height safety overspeed protection module

• Application: High-speed shaft overspeed protection for steam turbine, gas turbine and centrifugal compressor; Designed for emergency trip safety loop.

• Installation Rule: Any full-height slot in 3500 rack; redundant power supply is mandatory

• Compliance: API 670, API 612

2. Functional Description

• Channel Quantity: 3 independent keyphasor speed input channels

• Voting Logic: Support 2oo2 or 2oo3 voting trip configuration

• Sensor Type: Eddy-current probe or magnetic pickup sensor

• Response Speed: Ultra-fast trip response time ≤ 10 ms

• Working Mode: Fail-safe design for turbine ETS trip system

3. Electrical Specifications

• Backplane Power: +5 VDC from rack backplane

• Power Consumption: 9.5 W typical

• Speed Measuring Range: 0 ~ 99999 RPM

• Input Frequency Range: 0.017 Hz ~ 20 kHz

• Speed Accuracy: ±1 RPM high precision measurement

• Isolation Voltage: 1500 VAC channel-to-system isolation

4. Environmental Specifications

• Operating Temperature: -30 °C ~ +65 °C (-22 °F ~ +149 °F)

• Storage Temperature: -40 °C ~ +85 °C (-40 °F ~ +185 °F)

• Relative Humidity: 5% ~ 95% (Non-condensing)

• Anti-vibration: Compliant with API 670 industrial vibration standard

5. Mechanical Specifications

• Structure: Full-height single slot module

• Dimensions (H × W × D): 241.3 × 24.4 × 99.1 mm

• Weight: Approximately 0.62 kg

• Mounting: 3500 standard rack slot installation, hot-swap capable

6. Compatible Devices

7. Key Features

• Triple-channel redundant speed monitoring to avoid false trip

• 2oo3 voting logic for highest safety reliability

• Millisecond-level overspeed emergency trip response

• Fail-safe architecture compliant with turbine ETS system

• High anti-interference capability for harsh power plant environment

8. Difference Between 3500/53 & 3500/25

• 3500/25: Ordinary keyphasor card, only measure speed & phase, no trip function.

• 3500/53: Safety overspeed card, dedicated for ETS trip, triple redundant voting,safety protection level.