21747-040-00 | Bently Nevada 4m Extension Cable

Introduction to the Bently Nevada 21747-040-00

When your rotating machinery demands precise vibration monitoring, the 21747-040-00 from Bently Nevada delivers the reliable connection you need. This extension cable, part of the 21747 series, is engineered to link a probe with an integral lead to a Proximitor, ensuring accurate signal transmission over a 4-meter distance.

Manufactured by Bently Nevada, a trusted name in industrial monitoring, this cable is supplied new and in original factory packing. It carries a 12-month factory warranty, giving you confidence in its quality and performance.

Key Features and Technical Specifications

The 21747-040-00 is built for demanding environments. Its key specifications include:

• Cable Length: 4 meters (157 inches) – ideal for installations where the probe and Proximitor are separated by a moderate distance.
• Armor Option: 00 – without armor, offering a cost-effective solution for applications where physical abuse is not a primary concern.
• Power Requirements: Operates on -17.5 Vdc to -26 Vdc at 12 mA maximum consumption, ensuring low power draw.
• Calibrated Range: 80 mils (2.0 mm), beginning at approximately 10 mils (0.25 mm) from the probe face.
• Scale Factor: 200 mV/mil (7.87 V/mm), ±4% when calibrated as a system, with interchangeability errors within ±9.5%.
• Linearity: Within 0.8 mils (0.02 mm) of a 200 mV/mil straight line when calibrated as a system, and within 2.3 mils (0.06 mm) including interchangeability errors.
• Frequency Response: 0 to 10 kHz (0 to 600,000 cpm), with -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: Up to 95%, non-condensing.

One distinctive spec is the 4-meter length, which allows for flexible system design. This length is a common choice for installations where the Proximitor must be mounted away from the machine, providing installation flexibility without compromising signal integrity.

Industry Applications

The 21747-040-00 is widely used in industries that rely on rotating equipment, such as oil and gas, power generation, and manufacturing. It is a critical component in vibration monitoring systems for turbines, compressors, pumps, and motors.

For example, in a petrochemical plant, this extension cable connects a proximity probe on a large compressor to a Proximitor in a control cabinet, enabling continuous vibration monitoring. The cable's robust design ensures reliable performance in harsh industrial environments.

Installation and Setup

Proper installation is key to achieving accurate measurements. Here are some practical tips:

• Ensure the probe, extension cable, and Proximitor are of the same length and part number for complete interchangeability.
• Route the cable away from high-voltage lines and sources of electromagnetic interference to maintain signal quality.
• Secure the cable with appropriate clamps or ties to prevent stress on the connectors.
• Verify the power supply meets the -17.5 Vdc to -26 Vdc requirement before connection.

Following these guidelines helps ensure optimal performance and longevity of the system.

Maintenance and Reliability

To maintain reliable operation, inspect the extension cable periodically for signs of wear, cuts, or abrasion. Check connectors for tightness and corrosion.

Because this cable is without armor, it is more susceptible to physical damage, so regular inspection is especially important in environments with moving parts or heavy equipment. Early detection of issues can prevent costly downtime.

Compatibility and Integration

The 21747-040-00 is designed to work seamlessly with Bently Nevada probes and Proximitors. The combination of probe with integral lead and extension cable achieves a system length of either five or nine meters from probe tip to Proximitor, depending on the probe's integral lead length.

Probes and cables of the same length, and Proximitors with the same part number, are completely interchangeable, simplifying spare parts management and system expansion.

Comparison with Armored Options

Bently Nevada offers armored versions of extension cables for added protection. The armored option provides improved resistance to physical abuse, making it suitable for harsh environments. In contrast, the 21747-040-00 without armor is lighter and more flexible, which can simplify routing in tight spaces.

Choose the armored version if the cable is exposed to potential impact or abrasion; otherwise, the non-armored version offers a cost-effective solution.

Troubleshooting and Common Issues

If you experience signal loss or erratic readings, check the following:

• Verify that all connections are secure and free of corrosion.
• Inspect the cable for cuts or kinks that could break the conductor.
• Ensure the power supply is within the specified range (-17.5 Vdc to -26 Vdc).
• Confirm that the probe, cable, and Proximitor are matched in length and part number.

Addressing these common issues can resolve most problems.

FAQs about the 21747-040-00

Q: What is the length of the 21747-040-00 extension cable?

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

Q: Does the 21747-040-00 come with armor?

A: No, the armor option is 00, meaning it is without armor.

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 consumption of the 21747-040-00?

A: It consumes 12 mA maximum at -17.5 Vdc to -26 Vdc.

Q: Can I use this cable with any Bently Nevada probe?

A: It is designed for use with probes and Proximitors of the same length and part number for interchangeability.

Product Support and Availability

The 21747-040-00 is available from Petro Auto Tech, an industrial automation parts supplier. Please verify current lifecycle status and availability with Petro Auto Tech before ordering.