- Automation & ControlView all 1,921 products
- AC Drives
- PLC & I/O Cards
- Industrial Communications
- Vibration Monitoring
- Automation Accessories
- Controllers & Data Acquisition
- Isolator & Barrier
- CCTV & Security
- Safety Switches & Guard Locking
- Encoders
- HMI Displays
- Industrial Computers
- Motor Soft Starters
- Servo Drives
- Pneumatic Cylinders
- Machine Vision
- Automation Software
- Robotics
Brand: Bently Nevada
Bently Nevada 330850-50-00 3300 XL 25 mm Proximitor, 5 m Panel
Description
330850-50-00: 3300 XL 25 mm Proximitor Sensor, 5.0 m system, panel mount
The Bently Nevada 330850-50-00 is a 3300 XL 25 mm Proximitor Sensor for a 5.0 m (16.4 ft) system with four-hole panel mounting and no approvals option. It supports the 25 mm probe, whose 12.7 mm linear range suits differential expansion measurement on larger steam turbines.
Reading 330850-AA-BB for this part, 50 is the 5.0 m panel-mount system and 00 is no approvals.
| Segment | Code | Meaning (from the ordering table) |
|---|---|---|
| 330850 | 330850 | 3300 XL 25 mm Proximitor Sensor |
| A: total length and mounting | 50 | 5.0 m system length, panel mount |
| B: agency approval | 00 | No approvals |
330850-50-00 technical specifications
| Parameter | Specification |
|---|---|
| Manufacturer / part number | Bently Nevada 330850-50-00 |
| Product | 3300 XL 25 mm Proximitor Sensor |
| System length / mounting | 5.0 m (16.4 ft) including extension cable; panel mount |
| Agency approval option | 00 (no approvals) |
| Probe input | One non-contacting 3300 XL 25 mm probe with extension cable |
| Supply voltage | -17.5 to -26 Vdc at 12 mA maximum without barriers; -23 to -26 Vdc with barriers |
| Supply sensitivity | Less than 2 mV output change per volt of supply change |
| Output resistance | 50 Ω |
| Linear range | 12.7 mm (500 mils), from about 0.63 to 13.33 mm (25 to 525 mils), roughly -1.5 to -11.5 Vdc |
| Average scale factor | 0.787 V/mm (20 mV/mil) nominal |
| Deviation from best-fit line | Less than ±0.31 mm (±12 mils) |
| Frequency response | 0 to 2.7 kHz, +0/-3 dB typical, with up to 305 m of field wiring |
| Field wiring | 0.2 to 1.5 mm² (16 to 24 AWG), three-conductor shielded triad recommended, up to 305 m (1,000 ft) |
| Recommended minimum target | 61 mm (2.4 in) diameter, flat |
| Sensor operating temperature | -51 to +100 °C (-60 to +212 °F); storage -51 to +105 °C |
| Humidity | 100% condensing, non-submersible when connectors are protected; damp heat tested to IEC 68-2-3 |
| Sensor material and weight | A380 aluminum; 255 g (9 oz) |
Why the 330850-50-00 has such a low sensitivity
The 25 mm Proximitor Sensor drives a large-coil probe with a radio-frequency signal and converts the loading from the target into a negative dc voltage. The sensitivity is deliberately low, 0.787 V/mm (20 mV/mil), in return for a linear range of 12.7 mm (500 mils). That range is what lets two probes follow a rotor collar or ramp as the turbine rotor grows axially relative to its casing, which is the differential expansion (DE) measurement the datasheet names as the system’s main application.
330850-50-00: the shorter system for compact installations
A 5.0 m system suits turbines where the junction box can be mounted close to the casing. The combination of probe and extension must equal 5.0 m, for example a 1.0 m probe and a 4.0 m extension (330854 code 040), or a 5.0 m probe used on its own.
The datasheet frequency response of 0 to 2.7 kHz typical applies to the system with up to 305 m of field wiring. The panel base uses the same four-hole footprint as earlier designs.
Related parts and family overview for 330850-50-00
The 9.0 m panel version is 330850-90-00, and DIN versions are 330850-51-00 and 330850-91-00. The probes are 330851 and a sliding bracket 330853 can be added. The ordering table for 330850-AA-BB offers four length and mounting codes (50, 51, 90, 91) and two approval codes (00 and 05). The 25 mm line is only offered as 5.0 m and 9.0 m systems, so there is no 1.0 m sensor option as there is on the 8 mm line.
| Part number | System length | Mounting | Approval option |
|---|---|---|---|
| 330850-50-00 | 5.0 m (16.4 ft) | Panel mount | None |
| 330850-51-00 | 5.0 m (16.4 ft) | DIN mount | None |
| 330850-90-00 | 9.0 m (29.5 ft) | Panel mount | None |
| 330850-91-00 | 9.0 m (29.5 ft) | DIN mount | None |
Selection and ordering checklist for 330850-50-00
- Confirm differential expansion duty and the number of probes (single or complementary)
- Confirm the 5.0 m system total length
- Choose the probe case thread (1 1/4-12, M30x2, smooth) and armor
- Confirm panel-mount hardware is needed
- Confirm the monitor input scaling is for 20 mV/mil
- Check the sliding bracket and the dial indicator kit requirement
Installation, commissioning and maintenance of the 330850-50-00
Fit the sensor in the terminal box, connect the field wiring and plug in the extension cable. Probe and cable connectors are high-temperature ClickLoc types, and each probe is supplied with connector protectors and a disposable installation tool.
During commissioning, slide the transducer through its range and check the output against the dial indicator kit (163854), so the full 12.7 mm range is verified before the machine runs.
- Armored cable options add protection near hot casings
- Sensor temperature limit is +100 °C operating
- Replace the sensor as a whole; no individual component matching is needed
- Keep probe lead routing clear of moving parts
- Log the gap voltage and output at each position as a baseline
Typical applications in Oman and the GCC
In Oman and the GCC the 330850-50-00 appears on steam turbine generators in power stations, on desalination cogeneration units and on large industrial turbines in oil and gas and petrochemical sites. Differential expansion is a start-up and shutdown protection parameter, so the transducer is usually part of a monitored turbine train with several radial and axial channels.
Information to send with an RFQ for 330850-50-00
- Part number 330850-50-00 and quantity
- Probe part number and extension cable length (total 5.0 m)
- Turbine make and model
- Single or complementary DE arrangement
- Delivery location in Oman or the GCC and required date
Related Bently Nevada products: Bently Nevada 3300 XL 25 mm Proximitor Sensor 330850-51-CN, Bently Nevada 330105-02-12-10-02-05 3300 XL Probe, Bently Nevada 125680-01 3500/40M Proximitor I/O Module, Bently Nevada 3300 XL Proximitor 330180-51-CN, Bently Nevada 3300 XL 8mm Proximity Transducer System and Bently Nevada 3300 XL Proximitor 330180-50-05.
Documents and quotation
The manufacturer datasheet for the 330850-50-00 is attached on this page under Documents, so wiring, ordering options and environmental limits can be checked before you order.
Information on the 330853 sliding bracket and 163854 verification kit is also in the datasheet. Seven Star LLC is an independent supplier based in Muscat; submit the part number, quantity and delivery location and we reply with availability and a quotation.
Other Models in the 3300xl Proximitor 25mm Range
Seven Star LLC supplies models from the 3300xl Proximitor 25mm range in Oman and the GCC. Compare the related models below and request a quote for the one that matches your application.
| Model | Category | |
|---|---|---|
| Bently Nevada 330850-90-00 3300 XL 25 mm Proximitor, 9 m Panel | Vibration Monitoring | View details |
| Bently Nevada 330850-50-00 3300 XL 25 mm Proximitor, 5 m Panel | Vibration Monitoring | You are viewing this model |
Datasheets & Documents
- Datasheet Bently Nevada 330850-50-00 Datasheet Download
Reviews (0)
About brand
Bently Nevada is the American machinery protection and condition monitoring brand behind the 3500 rack, the 3300 XL proximity probe and the System 1 software. It was founded in 1961 in Minden, Nevada, and is today a Baker Hughes business.
Seven Star LLC is an independent supplier in Muscat. We list Bently Nevada monitors, I/O modules, probes, proximitors, velocity transducers and transmitters for rotating equipment in Oman and the GCC, and source them by full part number.
Bently Nevada company profile
| Established | 1961, Minden, Nevada, USA, by Donald E. Bently. The business started earlier as Bently Scientific in Berkeley, California (1956). |
|---|---|
| Known for | The first commercial eddy-current proximity transducers for measuring shaft vibration and position on high-speed turbomachinery |
| Ownership | Acquired by GE Energy in 2002; part of Baker Hughes since GE Oil & Gas combined with Baker Hughes in 2017 |
| Rack generations | 5000 series (from 1965), 3300 series (from 1988), 3500 series (from 1995), Orbit 60 (current platform) |
| Product families | Machinery protection racks, proximity probes and proximitors, Keyphasor sensors, velocity and acceleration transducers, 2-wire vibration transmitters, general-purpose monitors, portable analyzers, wireless sensors and System 1 condition monitoring software |
| Typical machines | Steam and gas turbines, centrifugal and reciprocating compressors, pumps, motors, generators, fans and gearboxes |
Milestones
- 1956: Donald E. Bently starts Bently Scientific in Berkeley, California.
- 1961: The company moves to Minden, Nevada, as Bently Nevada.
- 1965: The 5000 series monitoring system is introduced.
- 1988: The 3300 series follows.
- 1995: The 3500 machinery protection system is launched.
- 2002 and 2017: GE Energy acquires Bently Nevada; it becomes part of Baker Hughes in 2017.
Bently Nevada product series
| Series | Type | What it does |
|---|---|---|
| 3500 | Machinery protection rack | Continuous online protection with alarm and danger relays. Modules include the 3500/15 power supply, 3500/20 rack interface, 3500/25 Keyphasor, 3500/42M proximitor/seismic, 3500/50 tachometer, 3500/60 temperature, 3500/33 relay and 3500/92 communication gateway |
| 3500 recip modules | Reciprocating compressor monitoring | 3500/70M impulse velocity, 3500/72M rod position and 3500/77M cylinder pressure |
| Orbit 60 | Protection and monitoring platform | The current Bently Nevada platform for protection, condition monitoring and data integration with System 1 |
| 3300 XL 8 mm | Proximity transducer system | Probe, extension cable and proximitor sensor for radial vibration, thrust position and Keyphasor reference on fluid-film bearing machines; also 5 mm and 25 mm versions |
| 330500 Velomitor, 190501 Velomitor CT | Piezo-velocity sensors | Casing velocity on rolling-element bearing machines and low-speed cooling tower fans |
| 990 and 991 | 2-wire transmitters | 4-20 mA vibration (990) and thrust position (991) signals straight into a PLC or DCS, without a monitor rack |
| 1900/65A, 2300 | Compact monitors | Protection for balance-of-plant pumps, fans and motors where a full 3500 rack is not justified |
A proximity probe measures the gap to the shaft, so it sees shaft movement inside a fluid-film bearing directly. A velocity or acceleration sensor sits on the casing and suits rolling-element bearing machines. Critical turbomachinery usually carries two X-Y probes per bearing, two axial probes for thrust position and a Keyphasor probe for speed and phase.
Where Bently Nevada systems are used
In Oman and the GCC, Bently Nevada racks and probes protect gas turbines, compressors and steam turbines in gas processing, LNG, refining, petrochemical, power and desalination plants. Many installations are 3500 racks that have run for years, so most requests are for like-for-like module, probe, extension cable and proximitor replacements, plus upgrades to newer monitors.
Ordering and replacement: what we need
For probes and proximitors, send the full part number with all option digits (for example 330101-00-27-10-02-05). The digits set the probe length, cable length, connector and approvals, and the probe, cable and proximitor must match in total system length. For 3500 modules, send the module and I/O part numbers from the rack and say whether the I/O is internal or external termination, or barrier type. If a module is obsolete, we quote the replacement that Bently Nevada names and point out any configuration or firmware change.
Facts checked against Baker Hughes Bently Nevada pages and published company history, October 2026.
Browse Bently Nevada products by category: Vibration.
FAQ
Questions about the Bently Nevada 330850-50-00 3300 XL 25 mm
Answers from our engineering team on installation, compatibility and integration.
01What does 330850-50-00 mean?
It follows the 330850-AA-BB pattern. Code 50 is a 5.0 m system length with panel mount, and 00 means no approvals.
02Can the 330850-50-00 be used with older 7200 25 mm systems?
The datasheet says the 3300 XL 25 mm probe can physically replace 7200 25 mm and 35 mm and 25 mm DE integral transducers, but every component must be replaced with 3300 XL 25 mm parts.
03What is the system accuracy?
The datasheet gives a best-fit-line deviation of less than ±0.31 mm (±12 mils) with a nominal average scale factor of 0.787 V/mm.
04What temperature can the sensor operate at?
The Proximitor Sensor operates from -51 to +100 °C and stores from -51 to +105 °C.
05Which probe lengths pair with the 5 m sensor?
Probe plus extension must be 5.0 m, such as a 1.0 m probe plus 4.0 m extension, or a 5.0 m probe alone.
Reviews
There are no reviews yet.