PLCs, Power Supplies & Others

Intelligent Emergency Shutdown and Machinery Protection System

The Bently Nevada 3701/55 ADAPT Condition Monitor (ADAPT ESD) is a high-performance safety PLC designed to protect critical rotating machinery, including steam turbines, gas turbines, compressors, and expanders. It combines advanced overspeed detection, triple-redundant architecture, and graphical logic configuration to ensure rapid and reliable emergency shutdown operations in mission-critical environments.

This standalone system from Bently Nevada delivers exceptional reliability, offering built-in diagnostics, real-time monitoring, and compliance with international safety standards. Engineers use it widely across oil & gas, power generation, and heavy process industries to prevent catastrophic failures and improve system uptime.

Key Technical Specifications

Communication and Networking

The 3701/55 ADAPT monitor provides flexible Ethernet connectivity with six independent ports supporting both TCP/IP and static addressing. Engineers can modify network configurations through password-protected settings, ensuring secure access and control. The built-in NTP synchronization maintains precise timing across distributed systems.

Power and Electrical Characteristics

The 3701/55 ADAPT Condition Monitor operates on a stable 24 VDC supply with low power consumption, making it suitable for hazardous-area installations when used with certified supplies.

Input Specifications

Discrete Inputs

• Two-terminal, dry contact, polarity independent design
• Closed impedance: 57 kΩ max; open impedance: 187 kΩ min
• Low voltage threshold: 1.2 VDC max
• High voltage threshold: 2.9 VDC min
• Internal wetting voltage: 10–15 VDC
• Input resistance: 150 kΩ typical
• Fault tolerance: ±40 V

Analog Inputs

• Full-scale range: 4–20 mA ±1%
• Common-mode input range: ±32 V
• Differential range: 0–25 mA
• Frequency response: 0–159 Hz
• Faulted input tolerance: ±40 V

Proximity Speed Inputs

The system’s auto-threshold and hysteresis control maintain accuracy across varying signal strengths, ensuring stable overspeed protection.

System Architecture and Modules

The 3701/55 ADAPT ESD integrates three main hardware elements for optimal performance:

1. Processing Module – Core logic unit with embedded overspeed detection
2. Relay Output Module – Provides fast and isolated shutdown signals
3. Main ESD System Chassis – Houses power, communication, and interface units

Performance and Safety Features

• Triple-redundant configuration enhances system reliability
• Integrated overspeed detection ensures fast protective response
• Comprehensive self-diagnostics for fault isolation and maintenance
• Complies with major industry safety and control standards
• Graphical programming interface simplifies configuration and troubleshooting

Country of Origin, Size & Weight

• Origin: United States
• Total System Dimensions: 25.4 × 30.48 × 18.0 cm
• Total Weight: 8.8 kg (19.4 lb)

Details