Bently Nevada|3500/72M 176449-08| 4-channel monitor

Bently Nevada 3500/72M 176449-08 Recip Rod Position Monitor

The Bently Nevada 3500/72M is a 4-channel monitor designed to protect reciprocating compressors by measuring rod position, rod drop, and hyper-compressor displacement using proximity transducer inputs.

Features

• Accepts 1–4 proximity probe signals
• Measures dynamic and static position parameters
• Supports user-programmable alert and danger alarm setpoints
• Channels programmed in pairs, allowing two simultaneous functions
• Complies with API 618 for reciprocating compressor monitoring

Technical Specifications

Inputs

• Input Impedance: 10 kΩ
• Nominal Scale Factors:
  • Rod Position: 0.79–7.87 mV/µm (20–200 mV/mil)
  • Rod Position 2: 3.94–7.87 mV/µm (100–200 mV/mil)
  • Rod Drop: 3.94–7.87 mV/µm (100–200 mV/mil)
  • Hyper-Compressor: 3.94–7.87 mV/µm (100–200 mV/mil)

Power

• Consumption: 7.7 W (nominal)

Outputs

• Buffered Transducer Outputs: One coaxial connector per channel
• Output Impedance: 510 Ω
• Transducer Power Supply: -24 Vdc

Signal Conditioning

• Accuracy: ±0.33% typical, ±1% max (excluding filters)
• Frequency Response:
  • Peak-Peak Filter: Fixed 1 Hz to 600 Hz
  • Gap Filter: -3 dB at 0.09 Hz
  • Not 1X Filter: Constant Q notch, 34.9 dB rejection
  • 1X/2X Vector Filter: Constant Q, 57.7 dB rejection
• Valid Speed Range: 60–2130 cpm

Alarms

• Setpoint Range: 0–100% of full-scale
• Alarm Accuracy: ±0.13% of desired value
• Time Delays:
  • Alert: 1–60 sec
  • Danger: 0.1 sec nominal or 1–60 sec

Physical

• Monitor Dimensions: 241.3 × 24.4 × 241.8 mm
• Monitor Weight: 0.91 kg
• I/O Module Weights: 0.20 kg (non-barrier), 0.46 kg (barrier)

Environmental

• Operating Temp: -30°C to +65°C (standard), 0°C to +65°C (barrier modules)
• Storage Temp: -40°C to +85°C
• Humidity: 95% non-condensing