Bently Nevada 330701-00-20-10-11-00 3300 XL 11 mm Probe

330701-00-20-10-11-00 3300 XL 11 mm Proximity Probe Explained

The Bently Nevada 330701-00-20-10-11-00 is a 3300 XL 11 mm proximity probe, 330701 series, with a 1/2-20 UNF threaded stainless steel case and no armor. The 11 mm tip gives a 4.0 mm (160 mil) linear range at 3.94 V/mm (100 mV/mil), which is double the range of the standard 8 mm probe, so the 11 mm system is chosen where the shaft moves further than an 8 mm probe can follow. Seven Star LLC supplies the 330701-00-20-10-11-00 in Oman and the GCC as an independent supplier based in Muscat.

The datasheet lists the main uses as axial (thrust) position, ramp differential expansion on steam turbines, rod position or rod drop on reciprocating compressors, tachometer and zero speed measurement, and Keyphasor phase reference signals.

Decoding part number 330701-00-20-10-11-00

The ordering table for English-thread 11 mm probes uses the format Part Number-AA-BB-CC-DD-EE. Applying it to this part:

• 330701: 3300 XL 11 mm probe, 1/2-20 UNF thread, without armor
• AA = 00: unthreaded length 0.0 in, so the case is threaded over its full length
• BB = 20: overall case length 2.0 in (the case must be at least 1.0 in longer than the unthreaded length)
• CC = 10: total probe length 1.0 m (3.3 ft)
• DD = 11: miniature coaxial ClickLoc connector with connector protector, FluidLoc cable
• EE = 00: agency approval not required

Technical specifications

These are datasheet values for a 3300 XL 11 mm system at 0 to +45 °C, with a −24 Vdc supply and 10 kΩ load against a 4140 steel target, gapped at 2.5 mm.

How the 330701-00-20-10-11-00 works

The tip contains a coil excited at high frequency by the Proximitor Sensor. A conductive target in the field damps the coil, and the sensor converts the change into a dc voltage proportional to the gap, roughly −1 to −17 Vdc over the linear range. The 11 mm coil has a larger field than the 8 mm coil, which is why the range is longer but the scale factor is lower (3.94 V/mm instead of 7.87 V/mm).

The lower sensitivity also means the larger target and wider tip spacing. With two probes close together, cross-talk is limited by keeping a minimum tip separation, for example 64 mm (2.5 in) for axial position and 58 mm (2.3 in) for radial vibration on a 76.2 mm shaft.

System fit and related parts for 330701-00-20-10-11-00

The probe is part of a three-piece system with a 3300 XL 11 mm extension cable and a 3300 XL 11 mm Proximitor Sensor, supplied for 5 m or 9 m total length. A 1.0 m lead is therefore joined to a 4.0 m or 8.0 m extension cable. The 11 mm Proximitor Sensor was designed to replace 7200-series 11 mm and 14 mm transducer systems, but all components must be replaced together, and a 3500 system needs configuration software that lists the 3300 XL 11 mm option.

Other probes in the family include the armored 330702, the 5/8-18 330707 and 330708, the M14 x 1.5 330703 and 330704, the M16 x 1.5 330709 and 330710, and the reverse mount 330705 and 330706. This 330701 is the unarmored 1/2-20 version.

Selection checklist for 330701-00-20-10-11-00

• Confirm the 1/2-20 UNF thread against the existing bore; 5/8-18 and metric threads are different part numbers.
• Choose unthreaded and case lengths by measuring the mounting depth.
• Choose the lead length to match the Proximitor Sensor total length.
• Select FluidLoc cable if oil may travel along the cable; option 11 already includes it.
• Check if armor or approvals are required, because this part has neither.
• Confirm that the monitor channel is set for the 100 mV/mil scale factor.

Installation and maintenance of 330701-00-20-10-11-00

Set the gap to 2.5 mm, which is the middle of the linear range, and verify with the dc voltage at the Proximitor output. Tighten the locknut with its safety wire holes and do not exceed the rated torque. Connectors should be finger tight and covered with the connector protectors supplied with this ordering option. The silicone tape included with the extension cable is not recommended where the joint sees turbine oil.

The probe seals differential pressure with a Viton O-ring but is not pressure tested before shipping, so the user is responsible for containing any leakage. Temperatures below −34 °C can damage the seal. Keep a spare of the same case length for critical thrust positions.

Typical applications in Oman and the GCC

In Oman and the GCC the 11 mm probe is found on thrust bearings of steam turbines, compressors and large pumps in power generation, gas processing, refineries and desalination plants, and on reciprocating compressors where rod drop monitoring is used. High ambient temperature, humidity and dust make connector protection and correct cable routing important. Keyphasor and tachometer functions on large rotors also use this probe where a wide gap range is helpful.

11 mm probe thread options

What to send with your 330701-00-20-10-11-00 RFQ

• Part number and quantity.
• Machine, bearing and measurement type (thrust, rod drop, Keyphasor).
• Existing probe details and Proximitor Sensor part number.
• Extension cable length in service.
• Delivery destination.

Related Bently Nevada products: Bently Nevada 330105-02-12-10-02-05 3300 XL Probe, Bently Nevada 3300 XL Probe 330101-00-27-50-02-05, Bently Nevada 3300 XL 8mm Probe 330103-00-05-10-01-00, Bently Nevada 3300 XL 8mm Proximity Transducer System, Bently Nevada 3300 XL 25 mm Proximitor Sensor 330850-51-CN and Bently Nevada 32000-00-00-04-470-01-02 Proximity Probe Housing.

Documents and quotation

The 3300 XL 11 mm Proximity Transducer System datasheet (146256) is the source for the decoding above. Send the part number 330701-00-20-10-11-00 and we will confirm which documents we can provide alongside the quotation.

Use the RFQ form with quantity and delivery location and our Muscat team will confirm availability.