Vibration Monitoring for Air Handling Applications

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Monitoring the vibration of rotating components of enclosed air handling units presents a unique challenge for predictive maintenance programs. The air handling units are expected to maintain consistent environmental conditions, such as flow rate, temperature, and humidity - often at extremely limited tolerances. 

In many laboratory, manufacturing, and warehouse spaces, small deviations in operating parameters can result in void product. As a result, opening a unit to access the rotating components to collect vibration data, or even to perform a visual inspection, is impractical because of the potential for ambient air to affect conditions or introduce contaminants.

Common faults within air handling units include:

• Unbalance
• Misalignment between the sheaves
• Looseness
• Belt resonance defects / worn belts
• Worn or damaged sheaves
• Bearing defects
• Rubbing
• Motor electrical, including rotor bar faults

Vibration monitoring can be used on air handling units to:

• Reduce or eliminate exposure to safety hazards
• Reduce data collection time while increasing repeatability and data accuracy
• Collect data on previously inaccessible fan components
• Prevent high-cost failures
• Help ensure consistent environmental conditions

The first consideration is whether or not Process Monitoring or Dynamic Vibration Analysis is right for your condition monitoring program. Due to access concerns, permanent monitoring is the preferred method for repeatability, human safety, and operational effectiveness.

Process Monitoring requires 4-20 mA Loop Power Sensors, which will provide the overall vibration level of the machine so that it can be trended and alarmed using the plant's DCS, PLC, or SCADA system. Process Monitoring will require permanently-mounted Loop Power Sensors that output a 4-20 mA signal proportional to velocity or acceleration. Process Monitoring will provide an overall understanding of machine health, but cannot provide the same level of detailed diagnostic data as Dynamic Vibration Analysis.

Dynamic Vibration Analysis allows for trended data and machine health diagnostics. However, Dynamic Vibration Sensors can be paired with CTC's SC300 Series Signal Conditioners to create a hybrid approach for both Process Monitoring and Dynamic Analysis. A signal conditioner converts the signal from a dynamic vibration sensor into a 4-20 mA output, so it can be trended and alarmed using the plant's DCS, PLC, or SCADA system, and may also be used for more in-depth predictive maintenance.

Regardless of whether or not a signal conditioner is the correct choice for your program, CTC has a variety of vibration monitoring sensors for use in air handling applications.

GENERAL PURPOSE ACCELEROMETERS:
General Purpose Accelerometers typically meet the needs of air handling units. In limited-access areas, like near belt guards, side exit connector accelerometers are typically suggested. CTC's Dynamic Vibration IEPE Ultrasound Sensors also provide an excellent solution for general-purpose monitoring with the ability for high-frequency fault detection.

CTC offers a wide variety of General Purpose Accelerometers in top and side exit configurations, including:

AC102 and AC104
Standard Size Multipurpose Accelerometers, 2 Pin Connector, 100 mV/g, ±10%, ±80 g, Dynamic Range

AC292 and AC294
Premium Compact Size Accelerometers, 2 Pin Connector, 100 mV/g, ±5%, ±80 g, Dynamic Range

UEB332 and UEA332
Mini Size Dynamic Vibration IEPE Ultrasound Sensors, 1/4-28 Mounting, 2 Pin Mini-MIL Connector, 100 mV/g, ±10%, ±80 g, Peak

 

CABLES AND CONNECTORS:
Due to the environment within the air handling unit, the cable connecting the accelerometer to the switch box needs to be robust, chemically resistant, moisture resistant, as well as reliable in a caustic environment. CTC's Premium V Series Viton® Boots and A Series Standard MIL-Style Connectors are designed to perform in such environments.

a standard size side exit sensor, like AC104, attached to a V2N Viton Boot Connector

Our Viton® Boot (V Series) Connectors are a premium offering for the best chemical resistance and an IP69 rating for moisture concerns.

A standard size side exit sensor, like AC104, attached to an A2R Connector

Our A Series Connectors are a general-purpose offering that works in a variety of environments. A Series Connectors come with a stainless steel locking ring and a variety of material options, including Polycarbonate, PPS, and Nylon.

 

JUNCTION BOXES:
CTC's Junction Boxes can be used for local measurements or the transmission of data to online vibration monitoring systems. Junction Boxes can also be used for cable reduction purposes or for switched outputs during manual-route data collection of the vibration signals. Depending on the environment in which your junction box is mounted, CTC offers the majority of our enclosures in either fiberglass or stainless steel options.

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CTC is the world leader in the design and manufacture of industrial accelerometers and piezo velocity transducers, 4-20 mA vibration sensors, and proximity probe sets, as well as all related mounting hardware, cables and connectors, and junction boxes. Our products enable efficient vibration monitoring for predictive maintenance in a wide variety of industries. Industries served include cement, mining, petrochemical, food & beverage, auto, steel, wind, paper & pulp, power generation, water & wastewater treatment, pharmaceutical, hospitals, bottling, and more. Our mission is to offer the widest variety of accelerometers and vibration hardware products, which are compatible with data collectors and online monitoring systems, as well as the tools for installation.

The CTC product line features vibration analysis hardware for heavy industry. All CTC products are backed by our unconditional, lifetime warranty. If any CTC product should ever fail, we will repair or replace it at no charge.

CTC’s PRO Line offers the world’s most durable and reliable Proximity Probe Sets including drivers, probes, extension cables, and driver enclosures for 24/7 protection of critical machinery in the most demanding industrial environments. CTC PRO Line Proximity Probe Sets are compatible with all major data collectors. PRO Line products are covered by our best-in-class lifetime warranty on material and workmanship.


The TMP line features vibration analysis hardware for research and development. All TMP products are backed by a five-year warranty on materials & workmanship for standard sensors and a two-year warranty for all accessories, cables, connectors, and custom & private-labeled products.

CANCELLATION POLICY:
Stock, built-to-order, and private-label products qualify for free cancellation only if cancelled within 24 hours of order entry. 

After 24 hours of order entry:

• Stock products will be subject to a 25% cancellation fee
• Built-to-order and private-label products will be subject to a 50% cancellation fee

Custom products are non-cancellable at any time after the order is placed.

If you wish to cancel an order, please reach out to your CTC sales representative. The timestamp of when your email requesting cancellation was received will be honored for whether or not your request meets the free cancellation window.

RETURN POLICY:
All stock products may be returned for a 25% restocking fee if returned in new and unused condition within 90 days of shipment.

Built-to-order and private-label products qualify for a 50% refund if returned in new and unused condition within 90 days of shipment.

Custom products are quoted and built specifically to the requirements of the customer, which may include completely custom product designs or private-labeled versions of standard products for OEM customers. Custom products ordered are non-cancellable, non-returnable, and non-refundable.

EXPEDITED PRODUCTS CANCELLATION & RETURN POLICY:
All expedited CTC orders are non-cancellable and non-returnable.