The Bently Nevada 990-04-50-03-05 comes from the trusted 990 Vibration Transmitter family. This device works with one non-contacting 3300 NSv Proximity Probe and its extension cable. It converts shaft relative vibration directly into a standard 4-20 mA industrial signal. Many facilities rely on this transmitter for continuous machinery protection.
Input: The 990-04-50-03-05 accepts one 3300 NSv Proximity Probe with a matching extension cable. You must gap the probe between 0.5 and 1.75 mm (20 to 55 mils) from the target surface. Proper gapping ensures the full-scale measurement range performs accurately.
Power Requirements: This transmitter needs a +12 to +35 Vdc input at its terminal. It operates as a 2-wire loop-powered device. The 4 to 20 mA output corresponds directly to the specified full-scale vibration range.
Full-Scale Option: The unit provides 0-4 mils pp (0-100 μm pp) as its measurement span. This range works well for small vibration amplitudes on high-speed rotating equipment like turbines and compressors.
Output Accuracy: Loop accuracy stays within ±1.5% over the full-scale range. Bently Nevada rates this accuracy from the TEST signal input to a 250 Ω load resistor. Keep in mind that this ±1.5% error adds to the Prox Out Incremental Scale Factor.
Frequency Response: The frequency response covers 5 Hz to 6,000 Hz (+0, -3 dB). Therefore, this transmitter captures both low-speed and high-speed vibration events effectively.
Maximum Loop Resistance: You can use up to 1,000 Ω including cable resistance at 35 Vdc. For a typical 24 Vdc supply, a 250 Ω or 500 Ω loop resistor works well.
Current Limiting: The typical current limit is 23 mA. This feature protects the loop circuit during fault conditions or wiring errors.
NOT OK / Signal Defeat: When a NOT OK condition occurs, the output drops below 3.6 mA within 100 µs. After the fault clears, the signal restores automatically within 2-3 seconds.
The 990-04-50-03-05 includes the Agency Approval Option 05. It carries CSA Division 2, ATEX Zone 0, ATEX Zone 2, and ABS maritime approval. These certifications make it suitable for refineries, offshore platforms, chemical plants, and other explosive atmospheres.
Mounting Option: This model uses 03 DIN clips and screws for installation. The DIN clip system allows quick mounting on standard DIN rails inside control cabinets or junction boxes.
System Length Option: The system length is 5.0 metres (16.4 feet). This length connects the probe to the transmitter without requiring additional junction boxes or extension cables.
Transmitter Weight: The unit weighs only 0.43 kg (0.9 lbm). The shipping gross weight is 0.68 kg including packaging and mounting hardware.
Leadwire Length: The maximum distance for the Proximitor Sensor Output (BNC connector) is 3 meters (10 feet). Exceeding this distance may degrade signal quality.
Minimum Target Size: You need a target at least 9.5 mm (0.375 in) in diameter. Smaller targets will affect measurement linearity and accuracy.
First, mount the Bently Nevada 990-04-50-03-05 using the DIN clips and screws. Snap the transmitter onto a standard DIN rail inside a suitable enclosure. Next, connect the 3300 NSv Proximity Probe and its extension cable to the input terminals.
Then, apply DC power between +12 and +35 Vdc to the transmitter terminals. Use a two-wire shielded cable for the 4-20 mA current loop. The total loop resistance must not exceed 1,000 Ω at 35 Vdc.
After completing all wiring, gap the probe correctly. The recommended gap range is 0.5 to 1.75 mm (20 to 55 mils). Use the external zero and span adjustments to calibrate the output. These two adjustments are non-interacting, which simplifies setup significantly.
Additionally, never exceed the 3-meter cable limit for the BNC connector output. For hazardous area installations, use an approved power supply rated at 28 V. Always follow local electrical codes and plant safety procedures.
One Bently Nevada 990-04-50-03-05 990 Vibration Transmitter
DIN clips and screws (03 mounting option)
Factory configuration label with serial number
Quick start installation reference
1. Which probe works with the Bently Nevada 990-04-50-03-05?
This transmitter accepts one 3300 NSv Proximity Probe and its matching extension cable. You cannot use other probe models with this device.
2. Can I install this transmitter in a Zone 0 hazardous location?
Yes. The 990-04-50-03-05 carries ATEX Zone 0 approval. It also includes CSA Division 2 and ABS maritime certification for offshore use.
3. What happens if the probe or extension cable fails?
The output signal drops below 3.6 mA within 100 µs. This NOT OK condition alerts your PLC or DCS system immediately for fast response.
4. How do I adjust zero and span on this 990 transmitter?
Use the two external potentiometers located on the device housing. They are non-interacting, so changing zero does not affect the span setting.
5. What shipping methods do you offer for this item?
We ship via FedEx, UPS, or DHL. Delivery typically takes 3 to 7 business days depending on your destination country.
| Brand Name | Bently Nevada |
| Model No. | 990-04-50-03-05 |
| Product Type | Vibration Transmitter |
| hasMerchantReturnPolicy | Adjust according to reality |
| Shippingdetails | Adjust according to reality |
