190501-07-00-CN Bently Nevada Velomitor CT Velocity Transducer

Product Overview

The 190501-07-00-CN Velomitor CT (Cooling Tower) serves as a specialized seismic velocity transducer engineered specifically for the harsh, moisture-laden environments of industrial cooling towers and air-cooled heat exchangers. Unlike standard accelerometers, the Velomitor CT integrates internal circuitry that solid-state integrates acceleration into a velocity signal, providing a direct measurement of vibration severity in accordance with ISO standards.

This transducer excels in detecting mechanical looseness, gear mesh issues, and fan blade imbalances at the lower frequencies typical of cooling tower drive trains. By mounting the 190501 directly to gearboxes or fan motor housings, reliability engineers obtain a high-fidelity 3.94 mV/mm/s (100 mV/in/s) signal that is highly resistant to the electromagnetic interference (EMI) generated by large motor starters and variable frequency drives (VFDs).

Technical Configuration

The 190501-07-00-CN nomenclature defines a rugged hardware package optimized for heavy-duty industrial mounting and regional safety compliance.

Mounting Hardware Option (07)

The 07 option provides a Plate Stud (3/8-24 to 3/8-24). This heavy-duty mounting stud ensures a rigid mechanical coupling between the transducer base and the machine surface. A secure connection is vital for the accurate transmission of high-frequency vibration components to the internal sensing element.

Connection Option (00)

The 00 configuration utilizes the industry-standard MIL-C-5015 connection interface. This 2-pin threaded connector provides a robust, moisture-resistant seal when paired with a compatible Bently Nevada cable assembly, ensuring signal continuity even in high-humidity cooling tower "plenum" areas.

Agency Approval Option (CN)

The CN designation confirms that this unit carries global and regional hazardous area certifications. It meets ATEX/IECEx standards and specifically includes the Chinese NEPSI marking, making it mandatory for explosion-proof installations within the Chinese petrochemical and power generation sectors.

Technical Specifications

Engineering Advantages

The Velomitor CT series offers distinct durability advantages for balance-of-plant machinery:

• Corrosion Resistance: The 316L stainless steel housing resists the corrosive effects of chemically treated cooling water and salt-heavy coastal air.

• Internal Integration: By converting acceleration to velocity within the sensor itself, the 190501 eliminates the "noise" and phase-shift errors often introduced when integration is performed at the monitor or PLC level.

• Standardized Output: The 100 mV/in/s output is compatible with nearly all modern vibration monitoring systems, including Bently Nevada 3500/42M modules and Trendmaster systems.

Installation & Maintenance Guide

Precise mounting is the foundation of reliable velocity data in seismic sensors.

Surface Preparation

Ensure the mounting surface is flat to within 0.03 mm (0.001 in) and has a surface finish of at least 3.2 µm (125 µin). Use a light coating of silicone grease or mounting wax on the threads to improve the mechanical coupling and frequency response.

Torque Requirements

Tighten the 190501-07-00-CN to a torque of 4.5 N·m (40 in·lb). Under-tightening causes the sensor to "chatter," creating false high-frequency peaks, while over-tightening can damage the internal sensing crystal or the mounting stud.

Cabling and Grounding

The Velomitor CT uses a 2-wire system (Signal and Common). Always use shielded, twisted-pair cabling. Ground the shield only at the monitor/PLC end to prevent ground loops, which are a common source of 50/60 Hz noise in cooling tower applications.

Technical FAQs

Q1: How does the "CT" version differ from a standard 330500 Velomitor?

A1: The 190501 Velomitor CT is specifically tuned for the lower frequency ranges and lower vibration amplitudes found in cooling tower fan assemblies. It offers a broader frequency response at the low end (down to 1.5 Hz) compared to standard velocity sensors.

Q2: What is the significance of the "CN" approval for my project?

A2: If your facility is located in China or requires NEPSI certification for insurance compliance, the "CN" suffix is required. It guarantees that the sensor's explosion-proof properties have been verified by Chinese national laboratories in addition to ATEX/IECEx standards.

Q3: Can this sensor be mounted horizontally or vertically?

A3: Yes. The 190501 Velomitor CT is an omni-directional sensor. You can mount it in any orientation—vertical, horizontal, or inclined—without affecting the sensitivity or accuracy of the velocity measurement.

Q4: Is the MIL-C-5015 connector waterproof?

A4: The connector itself is hermetically sealed to the sensor body. However, for maximum longevity in cooling towers, we recommend using a boot-style weatherproofing kit or a sealed conduit connection over the cable-to-sensor junction.