Bently Nevada 330103 3300 XL 8 mm Proximity Non-armored Metric Probes

The Bently Nevada 330103 is a standard forward mount probe with metric M10×1 thread and without armor from the 3300 XL series 8 mm eddy current transducer system. This system is a global benchmark for condition monitoring of rotating machinery, widely used for vibration, displacement, speed, and Keyphasor measurements on turbines, compressors, fans, pumps, generators, and other critical equipment.

The 3300 XL 8 mm system is renowned for its advanced performance, high reliability, and complete interchangeability. The 330103 probe features M10×1 metric thread for standard forward mounting (i.e., installed from outside the machine by screwing into a mounting hole). The probe is supplied without armor (standard FEP insulated triaxial cable), offering excellent flexibility and temperature resistance. Its metric thread design is especially suited for equipment built to metric standards, particularly in Europe, Asia, and other metric‑region machinery manufacturers and end users.

This product fully complies with the American Petroleum Institute (API) 670 Standard for mechanical configuration, linear range, accuracy, and temperature stability. All 3300 XL 8 mm system components (probes, extension cables, and Proximitor sensors) are fully interchangeable, eliminating the need for matching or bench calibration of individual components – greatly simplifying field maintenance and spare parts management.

2. System Components

A complete 3300 XL 8 mm eddy current transducer system consists of three core components, with the 330103 probe being the key sensing element:

1. 330103 3300 XL 8 mm Metric Thread Probe (without armor) – Directly senses the distance to the conductive surface (e.g., shaft). Its M10×1 thread fits metric mounting holes, and the non‑armored design provides maximum cable flexibility.

2. 3300 XL Extension Cable – Connects the probe to the Proximitor sensor. The total system length (probe cable length + extension cable length) must match the Proximitor sensor’s rated length (e.g., 5 m or 9 m). The 330103 probe can be used with standard, armored, or FluidLoc extension cables (e.g., 330130 series).

3. 3300 XL Proximitor Sensor – Supplies a high‑frequency carrier signal to the probe, demodulates and amplifies the gap voltage. The output is a negative DC voltage proportional to the gap (typically -0 Vdc to -18 Vdc or -24 Vdc linear range) and can drive monitors or analyzers. Common model: 330180 series.

Important Notes:

• 1‑meter systems do not use an extension cable; the probe connects directly to the Proximitor.

• Factory default calibration target material is AISI 4140 steel. Calibration to other target materials is available upon request.

• The 330103 is electrically and physically identical to the imperial thread model 330101, except for the thread specification.

3. Key Features and Advantages

The 330103 probe incorporates many advanced designs from the 3300 XL series, while adding the convenience of metric threads.

3.1 Robust Mechanical Design

• TipLoc™ Molding – Patented probe tip molding provides a robust bond between the probe tip and body, preventing loosening or rotation, significantly improving vibration and shock resistance.

• CableLoc™ Design – The cable‑to‑probe body connection uses the patented CableLoc design, with pull strength up to 330 N (75 lbf), ensuring the cable does not detach under high stress.

• Metric M10×1 Thread – Thread size M10×1 conforms to international metric standards, allowing direct installation in metric mounting holes without adapters. Thread engagement characteristics are optimized for 8 mm probes.

• Standard Forward Mount – The probe is screwed into the mounting hole from outside the machine and secured with a lock nut – a straightforward and reliable installation method.

3.2 Reliable Electrical Connection

• ClickLoc™ Gold‑Plated Connectors – Corrosion‑resistant ClickLoc connectors between probe and extension cable require only finger tightening (an audible “click” indicates full engagement). The special locking mechanism prevents loosening due to vibration, and no special tools are needed.

• Connector Protectors – Optional connector protectors provide additional environmental protection against oil, moisture, and dust. The datasheet recommends connector protectors for all installations.

3.3 High RFI/EMI Immunity

• The 3300 XL Proximitor sensor and probe system exhibit high immunity to radio frequency and electromagnetic interference. Even when installed in fiberglass housings, nearby radio signals cause no adverse effects. The improved immunity meets European CE mark requirements without special shielded conduit or metal housings, reducing installation cost and complexity.

3.4 Easy Installation and Maintenance

• SpringLoc Terminal Strips – The Proximitor sensor’s SpringLoc terminal strips require no special tools. They provide fast, robust, vibration‑resistant wiring connections, eliminating screw‑type clamps that can loosen.

• Complete Interchangeability – 3300 XL 8 mm components (including the 330103 probe) are both electrically and physically interchangeable with non‑XL 3300 series 5 mm and 8 mm components. However, mixing XL and non‑XL components limits system performance to the non‑XL specifications.

4. Installation Considerations

1. Thread Engagement Length – For M10×1 metric threads, the maximum recommended engagement length is 5 mm (see datasheet page 8 table: M10×1 max engagement 5 mm). Exceeding this may cause binding or probe damage. Bently Nevada does not replace probes damaged by excessive thread engagement.

2. Mounting Torque – Follow the recommended torque values. Standard forward mount probes: 11.2 N·m (100 in·lbf) for full thread engagement; use 7.5 N·m (66 in·lbf) if only the first three threads are engaged. Maximum allowed torque is 33.9 N·m (300 in·lbf).

3. Lock Nut – Optional M10×1 probe lock nut with safety wire holes (part number 04301008) is available to secure the probe.

4. Connector Protectors – Strongly recommended for all installations (ordering options DD=01 or 11). Silicone tape (supplied with extension cables) is not recommended for connections exposed to turbine oil.

5. Minimum Bend Radius – The minimum cable bend radius is 25.4 mm (1.0 in). Excessive bending may damage the internal cable structure.

6. Metric/Imperial Mixing – The 330103’s M10×1 thread cannot be used with imperial mounting holes or lock nuts. Ensure the mounting base also has M10×1 threads.

5. Typical Applications

The 330103 metric non‑armored probe is particularly suited for:

• Metric‑standard rotating machinery – Turbines, compressors, generators manufactured in Europe, Asia, etc., with M10×1 mounting holes.

• Applications requiring high cable flexibility – Non‑armored cable is more flexible, easing routing through tight or curved conduits.

• Areas with moderate temperatures and low abrasion risk – Standard FEP cable withstands 177°C, suitable for most bearing housings.

• Metric plants needing uniform spares – The 330103 is electrically identical to the 330101, allowing metric facilities to stock a single metric‑thread spare.

6. Comparison with Related Models