Bently Nevada 990-04-50-01-01 Vibration Transmitter

SEO Title 2: Bently Nevada 990-04-50-01-01 990 Vibration Transmitter with DIN Rail Mounting

Product Introduction

The Bently Nevada 990-04-50-01-01 belongs to the reliable 990 Vibration Transmitter family. This device continuously monitors shaft vibration on rotating machinery such as compressors, pumps, and turbines. It works with a non-contacting 3300 NSv Proximity Probe and extension cable. The transmitter converts probe signals into a standard 4-20 mA loop current. What makes this version unique is the 35 mm DIN rail mounting option. This feature speeds up installation inside control cabinets. Additionally, the CSA Division 2 approval allows safe use in hazardous locations.

Technical Specifications of the 990-04-50-01-01

Measurement Range and Accuracy
This 990-04-50-01-01 covers a full-scale range of 0-4 mils pp (0-100 μm pp). Loop accuracy stays within ±1.5% over the specified full scale. This rating applies from the TEST input to a 250 Ω loop resistor. Keep in mind that the ±1.5% error adds to the Prox Out Incremental Scale Factor.

Power Requirements and Output Signal
The unit requires +12 to +35 Vdc at the transmitter terminal. Maximum loop resistance reaches 1,000 Ω including cable at 35 Vdc. Typical current limiting is 23 mA. The output signal ranges from 4 to 20 mAdc in a 2-wire configuration. Many existing control systems can accept this signal directly.

Frequency Response and Probe Setup
Frequency response spans 5 Hz to 6,000 Hz (+0, 3 dB). The probe must be gapped between 0.5 and 1.75 mm (20 and 55 mils) from the target to achieve the full scale range. Minimum target diameter is 9.5 mm (0.375 in). Proper gapping ensures accurate vibration readings.

Not OK Condition Behavior
When a Not OK condition occurs, the signal output drops to less than 3.6 mA within 100 µs. After the fault clears, the output restores within 2-3 seconds. This fast response helps downstream safety systems react immediately.

Mechanical Features and Mounting Options

DIN Rail Mounting
The mounting option 01 uses 35 mm DIN rail clips. This allows quick snap-on installation inside standard electrical cabinets. No special tools or drilling are required. Maintenance teams appreciate how easily they can remove or replace the unit.

Weight and Dimensions
Transmitter weight is 0.43 kg (0.9 lbm). The compact housing occupies minimal space on a DIN rail. You can place multiple units side by side for multi-channel monitoring.

System Length and Cabling
System length option is 5.0 metres (16.4 feet). For the Proximitor Sensor Output (BNC connector), the maximum cable distance is 3 metres (10 feet). Always respect these limits to maintain signal integrity.

Environmental Approvals
This model carries CSA Division 2 approval. It suits NonHazardous, Zone 2 or Div 2 Hazardous area locations. The recommended power supply voltage is 28 V.

Installation Guide for DIN Rail Version

Step 1 – Mount the Transmitter on DIN Rail
Snap the 990-04-50-01-01 onto a standard 35 mm DIN rail. Ensure the clips engage firmly. Leave enough space around the unit for wiring access.

Step 2 – Connect the Probe and Extension Cable
Connect one non-contacting 3300 NSv Proximity Probe and its extension cable to the transmitter. Keep total cable length within specified limits.

Step 3 – Wire the Power and 4-20 mA Loop
Apply +12 to +35 Vdc at the transmitter terminals. Use a 2-wire configuration for the 4-20 mA loop. Total loop resistance must stay below 1,000 Ω at 35 Vdc.

Step 4 – Adjust Probe Gap
Set the probe gap between 0.5 and 1.75 mm (20–55 mils) from the target surface. Use the non-interacting external zero and span adjustments for calibration.

Step 5 – Perform a Loop Test
Inject a TEST signal and measure voltage across a 250 Ω resistor. Verify the output stays within ±1.5% of the expected value.

Packaging List

• 1 x Bently Nevada 990-04-50-01-01 Vibration Transmitter

• 1 x 35 mm DIN rail clips (pre-installed)

• 1 x Product quick reference card

Note: Proximity probes, extension cables, and power supplies are sold separately.

Shipping and Delivery

We ship worldwide using FedEx, UPS, or DHL. All orders include tracking and standard insurance. Express shipping options are available upon request.

Frequently Asked Questions (FAQ)

1. What is the main difference between the 990-04-50-01-01 and the 990-04-50-02-01?
The 990-04-50-01-01 uses 35 mm DIN rail clips for mounting. The 990-04-50-02-01 uses bulkhead screws. Both share the same electrical specifications and performance.

2. Can I use this transmitter with a 24 Vdc power supply?
Yes. The 990 Vibration Transmitter accepts any voltage from +12 to +35 Vdc. A 24 Vdc supply works perfectly in most industrial panels.

3. How fast does the output drop during a probe failure?
Within 100 µs, the output goes below 3.6 mA. This fast shutdown helps prevent false readings during sensor faults.

4. What is the maximum cable length from the transmitter to the monitor?
The 4-20 mA loop can support up to 1,000 Ω total resistance. At 24 Vdc, this typically allows several hundred metres of cable depending on wire gauge.

5. Do I need to order the probe separately?
Yes. The 990-04-50-01-01 requires one 3300 NSv Proximity Probe and an extension cable. These are not included in the transmitter package.