190501-01-00-CN Bently Nevada Velomitor CT Velocity Transducer (ATEX/IECEx/NEPSI)

Product Overview

The 190501-01-00-CN represents a specialized version of the Bently Nevada Velomitor family, specifically the Cooling Tower (CT) variant. This piezoelectric velocity transducer measures absolute vibration of bearing housings, gearboxes, and motors. Unlike standard Velomitors, the CT version features a ruggedized design tailored to the unique low-frequency and high-moisture challenges found in cooling tower environments.

This sensor provides a high-fidelity 4-20 mA or raw signal output (depending on system integration) that allows Machinery Protection Systems to detect early-stage mechanical looseness, imbalance, or misalignment. Its non-contact-like reliability in a contact-style housing makes it the industry standard for monitoring critical balance-of-plant assets in power generation and petrochemical facilities.

Technical Configuration

The model 190501-01-00-CN follows a structured suffix logic to define its mechanical interface and regulatory compliance:

190501 - Base Model

Identifies the Velomitor CT Velocity Transducer. This model is specifically tuned for lower frequency ranges typically associated with cooling tower fans and slow-speed machinery.

01 - Mounting Hardware Option

This option includes a 3/8-24 to 3/8-24 stud. This hardware ensures a rigid mechanical coupling between the transducer and the machine casing, which is vital for accurate high-frequency vibration transmission to the internal piezo-element.

00 - Connection Option

This specifies a MIL-C-5015 connection interface. This 2-pin top-exit connector is the global industrial standard for vibration sensors, allowing for easy integration with shielded twisted-pair cabling and providing a moisture-resistant seal when properly booted.

CN - Agency Approval Option

The CN suffix indicates a multi-certification package including ATEX, IECEx, and Chinese NEPSI approvals. This allows for legal and safe installation in explosive atmospheres and hazardous zones within the Chinese domestic market and international projects.

Technical Specifications

Installation Guide

Correct mounting determines the quality of your vibration data. Observe these engineering requirements:

Surface Preparation

Ensure the mounting location is a flat, machined surface at least 32 mm (1.25 in) in diameter. The surface must be free of paint, rust, and debris. Apply a thin layer of silicone grease or acoustic coupling fluid to the mounting surface to improve high-frequency response.

Orientation

The 190501-01-00-CN detects vibration along its longitudinal axis. Install the sensor in the direction where the most significant vibration information is expected—typically in the radial (horizontal or vertical) direction for bearing monitoring.

Cable Management

Use a connector boot (part of the cable assembly) to prevent moisture ingress at the MIL-C-5015 junction. Secure the cable to the machine frame using clamps within 250 mm (10 in) of the sensor to prevent cable whip, which can introduce electronic noise into the signal.

Hazardous Area Wiring

Since this is a CN-rated unit (NEPSI/ATEX), you must install it in conjunction with an intrinsically safe (IS) barrier or galvanic isolator if the installation site is classified as a hazardous zone.

Engineering Advantages

The 190501-01-00-CN is engineered for the "Wet and Slow" conditions of industrial cooling systems.

• Low-Frequency Accuracy: Standard vibration sensors often lose accuracy below 10 Hz. The Velomitor CT maintains precision down to 1.5 Hz, making it capable of detecting faults on large, slow-moving fan blades.

• Corrosion Resistance: The 316L stainless steel housing resists the corrosive chemicals and constant humidity typical of cooling tower plumes.

• Global Compliance: The NEPSI certification (CN option) simplifies the procurement and inspection process for projects within China, ensuring compliance with local GB standards.

• High Signal-to-Noise Ratio: The internal electronics convert the high-impedance charge of the piezo-ceramic into a low-impedance voltage signal, allowing for long cable runs without signal degradation.

Technical FAQs

Q1: What is the difference between a standard 330500 Velomitor and this 190501 CT version?

A1: The 190501 (CT) is specifically designed for cooling towers. It has a different frequency response curve optimized for the lower RPMs of cooling tower fans, whereas the 330500 is a general-purpose sensor for higher-speed machinery.

Q2: Does the "CN" suffix change the physical dimensions of the sensor?

A2: No. The dimensions and weight remain the same as the standard version. The "CN" designation refers specifically to the labeling and the certification documentation required for NEPSI (China) and ATEX/IECEx hazardous area standards.

Q3: Can I mount this sensor using a magnetic base?

A3: While possible for temporary troubleshooting, a magnetic base acts as a low-pass filter and drastically reduces the sensor's frequency range. For permanent machinery protection, the provided 3/8-24 threaded stud (Option 01) is mandatory.

Q4: How do I verify if the sensor is functioning without a vibration shaker?

A4: You can check the DC Bias Voltage. When powered by a standard monitor or power supply, the transducer should output a steady DC bias (typically around 10-12 VDC). If the bias is at the supply voltage or 0V, the sensor or cable is likely faulted.