21747-040-01 | Bently Nevada 4m Armored Extension Cable

Introduction to the Bently Nevada 21747-040-01

When your rotating machinery demands reliable vibration monitoring, the 21747-040-01 from Bently Nevada provides a robust connection between probe and Proximitor. This extension cable, part of the 21747 series, is engineered to maintain signal integrity over a 4-meter (157-inch) length, with stainless steel armor for added physical protection.

Whether you are upgrading an existing system or installing new monitoring points, this cable ensures consistent performance. Its design focuses on durability and interchangeability, making it a practical choice for industrial environments.

Key Features and Technical Specifications

• Part Number: 21747-040-01
• Model: Extension Cable
• Manufacturer: Bently Nevada
• Cable Length: 4 metres (157 inches)
• Armor: With armor (stainless steel)
• Power: -17.5 Vdc to -26 Vdc at 12 mA maximum consumption
• Calibrated Range: 80 mils (2.0 mm), begins at approximately 10 mils (0.25 mm) from probe face
• Scale Factor: 200 mV/mil (7.87 V/mm), ±4% if calibrated as a system
• Linearity: Within 0.8 mils (0.02 mm) of a 200 mV/mil straight line if calibrated as a system
• Frequency Response: 0 to 10 kHz (0 to 600,000 cpm); -5% at 10 kHz
• Temperature Sensitivity: Typically -3% change in scale factor at +150°F (+65°C) at 50 mils gap (1.27 mm)
• Operating Temperature: Proximitor: -60°F to +212°F (-51°C to +100°C); Probe and Extension Cable: -30°F to +350°F (-34°C to +177°C)
• Relative Humidity: To 95%, noncondensing

The armored construction provides improved resistance to physical abuse, making it suitable for demanding field installations. The cable is designed to achieve a system length of either five or nine metres from probe tip to Proximitor, ensuring flexibility in system design.

Applications and Use Cases

This extension cable is ideal for vibration monitoring on rotating equipment such as turbines, compressors, and pumps. Its robust armor protects against mechanical damage in harsh industrial settings. Furthermore, the interchangeable design allows for easy replacement without recalibrating the entire system.

For engineers seeking reliable signal transmission over longer distances, the 21747-040-01 ensures minimal signal loss. Its frequency response of 0 to 10 kHz covers typical machine vibration frequencies, making it a versatile choice for condition monitoring.

Installation and Setup

When installing the 21747-040-01, ensure that the cable is routed away from sharp edges and excessive heat sources. The stainless steel armor provides a first line of defense, but proper installation practices further enhance longevity. Connect the cable securely to both the probe and the Proximitor, following Bently Nevada's recommended torque specifications.

Verify that the total system length (probe integral lead plus extension cable) matches the intended five or nine metre configuration. This ensures accurate calibration and optimal performance.

Maintenance and Reliability

Regular inspection of the cable and its connections is recommended to prevent downtime. Check for signs of wear, corrosion, or physical damage, especially in high-vibration areas. The armor significantly reduces the risk of damage, but periodic checks help maintain system integrity.

Given the temperature sensitivity of the scale factor, consider ambient temperature variations when interpreting measurements. The cable operates reliably within the specified temperature range, but extreme conditions may affect accuracy.

Compatibility and Integration

The 21747-040-01 is designed to work with Bently Nevada proximity probe systems. Probes and cables of the same length, and Proximitors with the same part number, are completely interchangeable. This simplifies inventory management and reduces spare parts complexity.

For detailed compatibility information, refer to the official Bently Nevada documentation or contact Petro Auto Tech for assistance.

Troubleshooting and Common Issues

If you experience signal loss or erratic readings, first check the cable connections for looseness or corrosion. Ensure that the cable is not pinched or damaged. Also, verify that the total system length matches the intended configuration, as incorrect lengths can affect calibration.

Should issues persist, consult the Bently Nevada manual or reach out to Petro Auto Tech for technical support.

FAQ about 21747-040-01

Q: What is the length of the 21747-040-01 extension cable?

A: The cable length is 4 metres (157 inches).

Q: Does the 21747-040-01 come with armor?

A: Yes, the armor option is '01 - With armor', providing stainless steel protection.

Q: What is the operating temperature range for the extension cable?

A: The probe and extension cable operate from -30°F to +350°F (-34°C to +177°C).

Q: What is the power requirement for the system?

A: The system requires -17.5 Vdc to -26 Vdc at 12 mA maximum consumption.

Product Support and Availability

The Bently Nevada 21747-040-01 is available from Petro Auto Tech, a trusted industrial automation parts supplier. We offer new and original factory-packed units with a 12-month warranty. Contact us for current availability and lifecycle status before ordering.