21747-085-00 | Bently Nevada 8.5m Extension Cable

Why Choose the Bently Nevada 21747-085-00 Extension Cable?

When your machinery monitoring system demands precise signal integrity over distance, the 21747-085-00 from Bently Nevada delivers. This extension cable is engineered to connect a probe with an integral lead to a Proximitor, achieving a system length of either five or nine meters from probe tip to Proximitor. With a cable length of 8.50 meters (335 inches), it provides the flexibility needed for various installation layouts.

Manufactured by Bently Nevada, a trusted name in industrial automation, this extension cable ensures reliable performance in demanding environments. It is supplied new and original in factory packing, backed by a 12-month factory warranty.

Key Features and Technical Specifications

• Model: 21747 - Extension Cable
• Cable Length Option: 085 – 8.50 meters (335 inches)
• Armor Option: 00 – Without armor
• Power Requirement: -17.5 Vdc to -26 Vdc at 12 mA maximum consumption
• Calibrated Range: 80 mils (2.0 mm), beginning 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; within ±9.5% including interchangeability errors
• Linearity: Within 0.8 mils (0.02 mm) of a 200 mV/mil straight line if calibrated as a system; within 2.3 mils (0.06 mm) including interchangeability errors
• Frequency Response: 0 to 10 kHz (0 to 600,000 cpm); -5% at 10 kHz (600,000 cpm)
• Temperature Sensitivity: Typically -3% change in scale factor at +150°F (+65°C) at 50 mils gap (1.27 mm)

One standout feature is the calibrated range of 80 mils (2.0 mm), which begins at approximately 10 mils (0.25 mm) from the probe face. This ensures accurate measurement even in tight clearances, making the 21747-085-00 suitable for high-precision monitoring tasks.

Installation and Setup

Installing the 21747-085-00 is straightforward. The combination of probe with integral lead and extension cable is designed to achieve a system length of either five or nine meters from probe tip to Proximitor. Probes are available with integral leads of various lengths to match average extension cable lengths. Probes and cables of the same length, and Proximitors with the same part number, are completely interchangeable, simplifying replacement and inventory management.

For installations requiring added protection, stainless steel armor is available as an option. This armor provides improved resistance to physical abuse, extending the cable's service life in harsh environments.

Environmental Durability

The 21747-085-00 is built to withstand challenging conditions. The Proximitor operates in temperatures from -60°F to +212°F (-51°C to +100°C), while the probe and extension cable handle -30°F to +350°F (-34°C to +177°C). With relative humidity up to 95% noncondensing, this cable is suitable for humid industrial settings.

For 8 mm probes, the probe operation is not affected by direct contact with air, water, lube oil, ammonium hydroxide, sulfuric acid (10%), MEK (methyl-ethyl ketone), or DMF (dimethylformamide). This corrosion resistance enhances reliability in chemically aggressive environments.

Maintenance and Reliability

To maintain optimal performance, inspect the extension cable periodically for signs of wear or physical damage. Ensure that all connections remain secure and free from contamination. Following the manufacturer's guidelines for installation and handling will help maximize the cable's lifespan and maintain measurement accuracy.

Because the 21747-085-00 is designed for interchangeability, replacing a damaged cable is simple—just match the length and part number. This reduces downtime and simplifies spare parts management.

Compatibility and Integration

The 21747-085-00 is part of the Bently Nevada 21747 series, designed to work seamlessly with compatible probes and Proximitors. The system length flexibility—five or nine meters—allows integration into various machine train configurations. Always verify compatibility with your existing Bently Nevada monitoring system before ordering.

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 length matches the system design requirements. If the cable is damaged, replace it with an identical 21747-085-00 to restore performance. For persistent issues, consult the official Bently Nevada documentation or contact Petro Auto Tech for technical support.

FAQs

Q: What is the length of the 21747-085-00 extension cable?

A: The cable length is 8.50 meters (335 inches).

Q: Does the 21747-085-00 come with armor?

A: No, the armor option is 00, meaning without armor. Stainless steel armor is available as an option for added protection.

Q: What is the power requirement for the 21747-085-00?

A: The power requirement is -17.5 Vdc to -26 Vdc at 12 mA maximum consumption.

Q: What is the calibrated range of the system using this cable?

A: The calibrated range is 80 mils (2.0 mm), beginning at approximately 10 mils (0.25 mm) from the probe face.

Q: Can the 21747-085-00 be used in high-temperature environments?

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

Product Support and Availability

The Bently Nevada 21747-085-00 is available from Petro Auto Tech, an industrial automation parts supplier. Contact Petro Auto Tech to confirm current availability and lifecycle status before placing an order. With a 12-month factory warranty, you can rely on the quality and authenticity of this product.