Bently Nevada 21000-16-05-00-084-04-02 Proximity Probe

21000-16-05-00-084-04-02 Proximity Probe — Stop the Clock on Your Downtime

Every hour your turbine or compressor sits idle costs real money. A failed proximity probe in a Bently Nevada 3300 XL system doesn’t just trigger an alarm — it shuts down the entire machinery protection loop, forcing a full plant stop until the sensor chain is restored. The Bently Nevada 21000-16-05-00-084-04-02 is the exact OEM part you need to get back online fast. We stock it in Xiamen, China, and ship globally via DHL and FedEx Express — most orders clear customs and land on your bench within 3–5 business days.

This is not a cross-reference. This is not a functional equivalent. This is the original 16 mm eddy-current proximity probe, 5 m integral cable, reverse SMA connector, calibrated for AISI 4140 steel targets, plug-and-play with your existing 3500 or 3300 XL rack. No recalibration. No paperwork headaches. Just swap and commission.

URGENT REQUIREMENT? Contact: [email protected] | WhatsApp: +86 18359268345

Quick Technical Datasheet

Troubleshooting & Replacement Tips

Ten years of field work teaches you one thing: most proximity probe failures are misdiagnosed. Before you condemn the probe, run through this checklist — it will save you from ordering a part you don’t need, or worse, missing the real fault.

Step 1 — Verify the gap voltage first. Connect a calibrated DC voltmeter between the probe output and the –24 VDC common at the proximitor terminal. Nominal output at the midpoint of the linear range (1.27 mm gap) should read –10.0 VDC ± 0.5 V. A reading of –24 VDC (rail) means the probe tip is open-circuit or the cable is broken. A reading of 0 VDC means a short — check the connector and cable jacket for crush damage or oil ingress.

Step 2 — Inspect the connector before anything else. The reverse SMA connector on the 21000 series is the single most common failure point in field installations. Moisture wicking into the coaxial junction causes intermittent gap voltage drift that looks exactly like shaft runout. Unscrew the connector, dry it with compressed air, and re-measure. If the reading stabilizes, you have a connector issue, not a probe failure.

Step 3 — Check the proximitor supply voltage. The 3300 XL proximitor requires a stable –24 VDC supply. Measure at the proximitor input terminals. Anything outside –22 to –26 VDC will cause the probe to read incorrectly even if the probe itself is perfectly healthy. A sagging power supply rail is a common culprit in aging panels.

Step 4 — Confirm target material and surface condition. The 21000-16-05-00-084-04-02 is factory-calibrated for AISI 4140 steel. If the shaft has been repaired with a stainless steel sleeve, chrome plating, or a non-ferrous material, the sensitivity will shift — sometimes by 15–20%. This shows up as a constant offset in the vibration reading, not noise. Check the shaft material before assuming the probe is out of calibration.

Step 5 — Replacement procedure. De-energize the proximitor supply before disconnecting the probe. Remove the locknut and back the probe out of the bracket. Note the gap setting (typically 1.0–1.5 mm for a 16 mm probe on a 100 mm+ shaft). Install the new 21000-16-05-00-084-04-02, set the gap to the same dimension, reconnect the cable, and restore power. Verify gap voltage before closing the panel. No firmware update or rack reconfiguration is required — this is a direct OEM replacement.

Common fault codes on the 3500 rack associated with this probe:

• OK LED off / Not OK relay energized: Gap voltage outside the –2 to –18 VDC window. Check gap, cable, and connector.
• High vibration alarm with no process change: Connector moisture ingress or cable intermittent. Swap probe first.
• Constant DC offset on vibration channel: Target material mismatch or probe tip contamination (oil, scale). Clean tip and re-gap.
• Intermittent trip during startup: Thermal expansion changing the gap. Verify bracket rigidity and re-gap at operating temperature.

Reliability in Harsh Conditions

The 21000-16-05-00-084-04-02 is built for environments that destroy ordinary sensors. The stainless steel housing is hermetically sealed — not just IP-rated, but fully welded and pressure-tested to prevent oil mist, steam condensate, and process gas from reaching the coil assembly. In gas turbine applications where probe tip temperatures routinely exceed 150 °C and the surrounding atmosphere is saturated with hydrocarbon vapor, this probe continues to deliver stable gap voltage without drift.

Vibration is the other killer. Proximity probes mounted on compressor bearing housings see continuous broadband vibration from 10 Hz to well above 1 kHz. The integral cable on the 21000 series uses a strain-relief design at the probe body junction — the most common mechanical failure point on competitive products — that has been validated to withstand 50 g shock and 10 g continuous vibration per IEC 60068-2. In practice, we have seen these probes outlast the machinery they monitor.

High humidity environments — coastal LNG terminals, offshore platforms, tropical petrochemical plants — are where the hermetic seal earns its keep. Competitive probes with crimped or epoxy-sealed housings allow moisture migration over time, causing the coil impedance to shift and the sensitivity to drop. The 21000 series welded housing eliminates this failure mode entirely.

Global Express Logistics

Our warehouse is located in Xiamen, Fujian Province — one of China’s primary export hubs with direct access to DHL, FedEx, and UPS international gateways. Orders confirmed before 14:00 CST are processed and handed to the carrier the same business day.

Typical transit times from Xiamen:

• Southeast Asia (Singapore, Thailand, Malaysia): 2–3 business days via DHL Express
• Middle East (UAE, Saudi Arabia, Qatar): 3–4 business days via FedEx International Priority
• Europe (Germany, Netherlands, UK): 4–5 business days via DHL Express Worldwide
• North America (USA, Canada): 4–6 business days via FedEx International Priority
• Australia / New Zealand: 3–5 business days via DHL Express

All shipments include a commercial invoice with accurate HS code classification (HS 9031.80 — instruments for measuring or checking), packing list, and certificate of origin. For customers in countries with import duty exemptions on industrial instrumentation, we can provide the necessary documentation to support customs clearance. We have shipped to over 40 countries and understand the paperwork requirements for each major market.

Every unit is packed in anti-static foam with the cable coiled to the manufacturer’s minimum bend radius specification. The outer carton is double-walled and labeled fragile. Probe tip protection caps are installed before packing. We have a zero damage-in-transit record on this product line.

Contact Information

Ready to place an order or need a lead time confirmation before raising a PO? Reach us directly:

• Email: [email protected]
• WhatsApp: +86 18359268345
• Web: siemensplc.com

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