System Compatibility

• Probes & Cables: Connects strictly to a 3300 XL 50 mm proximity probe (330876) and extension cable (330877) that combine to match the 5.0-meter total system length
• Legacy Interactivity: Features a 0.394 V/mm (10 mV/mil) output that matches older 7200 50 mm and 50 mm DE Integral systems, allowing direct drop-in replacement without upgrading monitor configurations.
• Field Electrical Termination: Connects to field machinery monitors via onboard SpringLoc terminal strips supporting 0.2 to 1.5 mm² (16 to 24 AWG) shielded triad cable wires

Substitute Model & Technical Differences

• Alternative Suffix Version: 3300 XL 50 mm Proximitor Sensor Panel Mount (Model: 330878-50-05)
• Key Differences:

• Mechanical Mounting Style: The 330878-51-05 is engineered with a DIN-mount adapter base plate for quick clamping onto standard 35mm DIN rails.The 330878-50-05 features a flat panel-mount base with pre-drilled hardware pads for direct structural panel face attachment.
• Physical Footprint Profile: The DIN-mount option extends to a total height profile of 70.8 mm (2.79 in) due to the rail adapter latch mechanism, whereas the flat panel-mount variant maintains a lower overall physical height profile of 63.5 mm (2.50 in).

Applications

330878-51-05 is primarily used for differential expansion (DE) and rotor expansion (RX) measurements in large steam turbine generators. It monitors axial movement between rotor and casing caused by thermal growth differences. The system is ideal for thrust bearing proximity measurement, collar position tracking, and high-precision monitoring in power plants, ensuring safe turbine operation and reliable condition assessment.

Installation & Troubleshooting FAQ

Q1: What power and supply voltage rules apply to setting up the 330878-51-05 sensor safely?
A: The unit requires a regulated supply input of -17.5 VDC to -26 VDC when wired without barriers, or -23 VDC to -26 VDC with electrical barriers. Operating the unit with a voltage more positive than -23.5 VDC will compress or reduce the linear calibration range.

Q2: Can I combine a 1-meter probe with a 4-meter extension cable to pair with this 5.0-meter Proximitor?
A: Yes. You must always ensure that the physical probe leading cable length and the extension cable length, when added together, exactly match the 5.0-meter Proximitor total system calibration rating.

Q3: The system output voltage is fixed at approximately -1.5 VDC. Is the sensor gapped correctly?
A: No, -1.5 VDC marks the very beginning of the extra-long linear range. Adjust your probe gap clearance further away from the target track until the multimeter scales into the formal -1.5 to -12.5 VDC linear operating zone, which correlates to a physical gap clearance of 1.3 to 29.2 mm (50 to 1150 mils).

Q4: My system output values are drifting erratically when adjacent high-frequency radios are keyed. How do I fix this?
A: The Proximitor incorporates advanced internal RFI/EMI shielding to suppress nearby radio signals. If interference happens, verify that the field wiring shield drain wire is properly landed at the monitor terminal block and ensure the Proximitor housing is clean and securely clipped onto a grounded DIN rail.

Q5: What target material must be present to maintain the accuracy and scale factor stated on the datasheet?
A: The sensor is factory-calibrated to a standard AISI 4140 steel target that is flat and has a minimum diameter of 102 mm (4.0 in). System accuracy and interchangeability specifications are not valid if calibrated to non-standard or alternative target alloys.

Spares