January 18, 2014 – For the Smart Grid system to work reliably, phasor measurement units (PMUs) must be calibrated so that their data is consistent, accurate, and credible, and so that models from different manufacturers are inter-operable. NIST, The National Institute of Standards and Technology, felt so strongly about the need for a PMU calibrator that it awarded Fluke a development grant in 2010 to get the project underway. The resulting Fluke Calibration 6135A/PMUCAL Phasor Measurement Unit Calibration System is the only automated and traceable PMU calibration system available today. It fills an essential need for PMU designers and manufacturers, as well national metrology institutes, third party calibration houses, and electrical utilities.
October 07, 2013 – Fluke Corporation introduces the Fluke VT04 Visual IR Thermometer, the latest troubleshooting tool with built-in digital camera and thermal heat map overlay that bridges the gap between traditional IR thermometers and infrared cameras. Building on the extremely popular Fluke VT02, the VT04 adds PyroBlend Plus with a four-times sharper resolution than the VT02 and automatic alarm features. It is the ideal frontline troubleshooting tool for electrical, industrial maintenance, HVAC/R, and automotive applications.
August 6, 2013 - Fluke has developed a series of predictive maintenance application notes that focus on helping maintenance professionals implement proactive techniques that promise to save them time and money. Each application note is presented as a free downloadable PDF, and Fluke says to check back regularly as the PdM library continues to grow. Current notes include:
PdM Part 1: Predictive maintenance overview - This overview explains the different kinds of methods, terms, standards and cost equations, and provides basic process steps and an equipment list.
PdM Part 2: Applying hand-held test tools to predictive maintenance - Basic strategy, cost analysis, tool advice, key indicators and measurement guidelines for using DMMs (digital multimeters), clamp meters, insulation resistance testers and infrared thermometers.
PdM Part 3: Applying infrared thermography to predictive maintenance - Guidelines for integrating thermography into a cost-effective PdM program; includes cost analysis and measurement guidelines.
PdM Part 4: Six simple ways to reduce costs with a Fluke 434 power quality analyzer - Straightforward descriptions, cost calculations and How-Tos for six power quality measurements: voltage imbalance, THD, phase current, voltage sags, peak demand and power factor.
PdM Part 5: Insulation resistance testing on lighting circuit wiring - This case study describes the methodology used by Minneapolis Airport technicians to check leakage to ground along their lighting wiring paths. Step-by-step instructions and preventive maintenance scheduling examples included.
July 3, 2013 - Fluke Calibration introduced the 3130 portable pneumatic pressure calibrator, a complete system for pressure sensor and pressure gauge calibration, on the bench or in the field. The 3130 digital pressure calibrator contains everything needed to generate, control, and measure pressure, as well as read the output of the device under test, says the company. It includes an onboard pressure sensor with a full scale of 2 MPa (300 psi, 20 bar) and an accuracy of 0.025%, reading plus 0.01% FS. For applications that involve filling a large volume with pressure, the 3130 allows for connection to an external gas supply, such as compressed plant air or gas cylinder, to supply pressure up-to-300 psi. The pressure can be fine-tuned using the variable volume. The 3130 includes electrical measurement capabilities, pressure switch testing, and pressure transmitter and pressure transducer calibration.
The 709H supports a select set of HART universal and common practice commands. In the communicator mode, technicians can read basic device information, perform diagnostic tests, and trim the calibration on most HART-enabled transmitters. In the past, this could only be done with a dedicated communicator, a high-end multifunction calibrator, or a laptop computer with a HART modem. It also features a built-in, selectable 250-ohm resistor to tune the loop for HART communications.
The 709H and non-HART 709 models feature an intuitive interface with dedicated buttons, a Quick-Set rotary encoder knob, and simple two wire connection for quick, easy measurements. The dedicated 0-100-per-cent span and 25-per-cent step buttons make for quick and easy testing. Ramping and auto-stepping enables technicians to perform tests remotely and be in “two places at once.”
The optional 709H/TRACK software with communication cable can document milliamp measurements and HART transmitter parameters and upload to a PC.
High-tech electronics in today’s medical, communications, navigation and military devices routinely operate at high speeds requiring higher bandwidth. Correct display of waveforms with high frequency content such as clock pulses requires a bandwidth of at least five times the clock rate of the system under test. The 5 GS/s — or 200 pico seconds — sample rate of the Fluke 190-502 provides greater accuracy and clarity of shape and amplitude of unknown waveform phenomena like transients, induced noise and ringing or reflections.
The rugged 190 Series II ScopeMeter test tools include innovative functions like ScopeRecord, TrendPlot, advanced triggering and automatic measurements functions you would expect to find in high performance scopes. The 190 Series II safety rating according to IEC 61010 standard is 1000 V CAT III/ 600 V CAT IV making it possible to safely measure from mV to 1,000 V.
But how can a maintenance professional tell the difference between acceptable vibration and the kind that requires immediate attention to service or replace troubled equipment?
Vibration is not always a problem. In some tasks, vibration is essential. Machines like oscillating sanders and vibratory tumblers use vibration to remove materials and finish surfaces. Vibratory feeders use vibration to move materials. In construction, vibrators are used to help concrete settle into forms and compact fill materials. Vibratory rollers help compress asphalt used in highway paving.
In other cases, vibration is inherent in machine design. For instance, some vibration is almost unavoidable in the operation of reciprocating pumps and compressors, and internal combustion engines. In a well-engineered, well-maintained machine, such vibration should be no cause for concern.
When vibration is a problem
Most industrial devices are engineered to operate smoothly and avoid vibration, not produce it. In these machines, vibration can indicate problems or deterioration in the equipment. When the underlying causes are not corrected, the unwanted vibration itself can cause additional damage. This article focuses on machines that are supposed to vibrate as part of normal operation, but on those that should not vibrate: electric motors, rotary pumps and compressors, and fans and blowers. In these devices, smoother operation is generally better, and a machine running with zero vibration is the ideal.
Vibration can result from a number of conditions, acting alone or in combination. Keep in mind that vibration problems may be caused by auxiliary equipment, not just the primary equipment. These are some of the major causes of vibration.
A ‘heavy spot’ in a rotating component will cause vibration when the unbalanced weight rotates around the machine’s axis, creating a centrifugal force. Imbalance could be caused by manufacturing defects (i.e. machining errors, casting flaws) or maintenance issues (i.e. deformed or dirty fan blades, missing balance weights). As machine speed increases, the effects of imbalance become greater. Imbalance can severely reduce bearing life as well as cause undue machine vibration.
Vibration can result when machine shafts are out of line. Angular misalignment occurs when, for example, the axes of a motor and pump are not parallel. When the axes are parallel but not exactly aligned, the condition is known as parallel misalignment. Misalignment may be caused during assembly or develop over time due to thermal expansion, components shifting or improper reassembly after maintenance. The resulting vibration may be radial or axial (in line with the axis of the machine) or both.
As components such as ball or roller bearings, drive belts or gears become worn, they may cause vibration. When a roller bearing race becomes pitted, for instance, the bearing rollers will cause a vibration each time they travel over the damaged area. A gear tooth that is heavily chipped or worn, or a drive belt that is breaking down, can also produce vibration.
Vibration that might otherwise go unnoticed may become obvious and destructive when the component that is vibrating has loose bearings or is loosely attached to its mounts. Such looseness may or may not be caused by the underlying vibration.
Whatever its cause, looseness can allow any vibration present to cause damage, such as further bearing wear, wear and fatigue in equipment mounts and other components.
The effects of vibration can be severe. Unchecked machine vibration can accelerate rates of wear (i.e. reduce bearing life) and damage equipment. Vibrating machinery can create noise, cause safety problems and lead to degradation in plant working conditions. Vibration can cause machinery to consume excessive power and may damage product quality.
In the worst cases, vibration can damage equipment so severely as to knock it out of service and halt plant production.
Yet there is a positive aspect to machine vibration. Measured and analyzed correctly, vibration can be used in a preventive maintenance program as an indicator of machine condition, and help guide the plant maintenance professional to take remedial action before disaster strikes.
Characteristics of vibration
To understand how vibration manifests itself, consider a simple rotating machine like an electric motor. The motor and shaft rotate around the axis of the shaft, which is supported by a bearing at each end.
One key consideration when analyzing vibration is the direction of the vibrating force. In our electric motor, vibration can occur as a force applied in a radial direction (outward from the shaft) or in an axial direction (parallel to the shaft). An imbalance in the motor, for instance, would most likely cause a radial vibration, as the heavy spot in the motor rotates creating a centrifugal force that tugs the motor outward as the shaft rotates through 360 degrees.
A shaft misalignment could cause vibration in an axial direction (back and forth along the shaft axis) due to misalignment in a shaft coupling device. Another key factor in vibration is amplitude, or how much force or severity the vibration has. The farther out of balance our motor is, the greater its amplitude of vibration. Other factors, such as speed of rotation, can also affect vibration amplitude. As rotation rate goes up, the imbalance force increases significantly.
Frequency refers to the oscillation rate of vibration, or how rapidly the machine tends to move back and forth under the force of the condition or conditions causing the vibration. Frequency is commonly expressed in cycles per minute or Hertz (cpm or Hz). One Hz equals one cycle per second or 60 cycles per minute.
Though we called our example motor “simple”, even this machine can exhibit a complex vibration signature. As it operates, it could be vibrating in multiple directions (radially and axially), with several rates of amplitude and frequency. Imbalance vibration, axial vibration, vibration from deteriorating roller bearings and more could all combine to create a complex vibration spectrum.
Vibration is a characteristic of virtually all industrial machines. When vibration increases beyond normal levels, it may indicate only normal wear, or it may signal the need for further assessment of the underlying causes, or for immediate maintenance action. Understanding why vibration occurs and how it manifests itself is a key first step toward preventing vibration from causing trouble in the production environment.
This article is based on the Fluke white paper “Introduction to vibration.” For more information, visit www.flukecanada.ca.
“Many plant managers can have their energy costs reduced by 40 per cent,” asserts Thierry Desjardins, vice-president of engineering at Québec City-based Ecosystem, an award-winning, ISO-certified energy efficiency firm. He says the first 35 per cent of these energy cost savings can be achieved through optimally designed and implemented energy conservation measures (ECMs), like boiler room retrofits, switching to more efficient motors/variable frequency drives, using geothermal systems, undertaking lighting system retrofits and replacing chillers.“However, one of the most critical factors for reaching optimal energy savings and maximizing your ROI is to make sure that the correct ECMs are selected and implemented at the same time, based on a nuanced understanding of how each measure can interact with the others,” Desjardins explains. “Too often, plant managers lose out on the full benefits of a retrofit because the ECMs are assessed, designed and implemented in isolation.”
He calls this “a major opportunity lost” that can have a significantly negative impact on cost-return timelines. He stresses that “the order in which measures are implemented can have a major impact on project payback and feasibility.” Here’s a simple example scenario showing how a chosen ECM can interact negatively with others to prevent maximal energy cost savings: “If you replace the central chiller before carrying out a lighting conversion,” Desjardins explains, “you’re going to end up purchasing a machine that is too big. Not only will you have paid too much for your chiller, but the efficiency won’t be optimal because the equipment isn’t optimally sized.”
To maximize ECM decision-making benefits, he strongly recommends turning to an expert for an energy audit of the facility. “This step is crucial because all buildings are different, and each building is far more than the sum of its mechanical parts,” he says. “You really need an experienced ‘outside eye’ to look at the building’s unique energy infrastructure and get a grasp of how energy is generated, distributed and used throughout.”
Proper maintenance of all mechanical systems — such as a steam trap survey and replacement, and fixing leaks in compressed air networks — typically amount up to the remaining five per cent of energy savings, Desjardins says. Even though five per cent might seem insignificant, it adds up over time.
“Without proper maintenance, the most efficiently designed buildings will not achieve energy goals,” agrees Kris Bagadia, president of U.S.-based Peak Industrial Solutions. “As mechanical systems are used to heat and cool a building, system performance degrades as sensors and meters drift out of calibration. If these systems are not maintained, they begin to consume more energy as equipment wears.”
That’s why he says it’s critical to effectively track and manage energy consumption. “That’s where a CMMS (computerized maintenance management system) plays an important role,” he says. “It allows you to gather and manage maintenance and energy data, which go hand-in-hand for effective maintenance management.” A CMMS can provide the ability to schedule inspections of energy-consuming equipment, to collect and store historical energy-consumption data that can be used to identify problem areas related to energy (such as leaks) and to establish an effective energy-reduction plan. “It also provides the ability to provide tracking of energy-consumption with user-defined criteria,” Bagadia says, “and correlate those criteria to how much energy is being consumed, as well as details of how much energy is being consumed by an individual asset, location, or building or facility.”
Both the two main types of maintenance planning — preventive maintenance (PM), also known as calendar-based maintenance, and predictive maintenance (PdM) — are effective strategies in achieving both consistent production goals and energy savings, says Peter Hachey, business development specialist of power quality and more for Fluke Electronics Canada. “Either way, the right tools must be used to properly diagnose the problem in a given situation,” he notes.
Below, Hachey examines three examples of energy-related challenges that a maintenance manager may typically face — as well as the lessons learned as the problems were solved.
1) Sub-metering of plant compressor group
“While a vital component of many manufacturing facilities’ operations, air compressors can be a source of energy waste,” Hachey notes.
He says the two most typical sources of waste are leaks in piping and improper time-of-day usage. Both can occur at once, and require different tools to diagnose the problem.
In this example, the air compressor was believed to be the culprit when a year-to-year increase in plant power consumption was noticed — an increase that could not be tied to a change in production practices. “Because the compressor piping circuit had never been included in any PM, the logical first step was to inspect the piping in order to locate any air leaks along in the network,” Hachey notes. “The most effective tool for this task is an ultrasonic leak detector, which will detect any type of pressurized gas/air leak.” The maintenance technician mapped the plant’s compressed air piping system and several leaks were found.
The technician also checked out any further issues. Because he was unsure of the usage sequence of the compressors, he decided the best course of action was to use a three-phase power quality analyzer to record power consumption on the compressor circuit, set to record for one full week.
“The analyzer’s trend mode delivered a surprising result — the compressors were left running even when the plant was shut down for the weekend,” he notes.
“The solution here was to institute a policy of shutting down the compressors whenever operations are suspended. … Needless to say, annual inspection of the compressor system was added to the PM list.”
2) Poor lighting-cicuit configuration
Hachey makes the case that upgrades to existing lighting systems for the purpose of energy savings have to be done correctly — or lighting energy waste issues may occur.
In this example, a plant manager requests that the maintenance/facilities manager increase the efficiency of the plant’s lighting configuration. His tasks include measuring light levels in order to add lighting as required, installing new high-efficiency electronics ballasts and installing a PLC to automate light levels according to time-of-day need.
A light meter is employed to identify areas where lighting is insufficient. “The levels are recorded and a lighting specialist is called to specify the correct number of fixtures to achieve the desired brightness,” Hachey says. “Steps two and three, installing the new ballasts and integrating the system into a PLC, are then carried out in the newly-installed lights as well as throughout the plant.”
However, shortly after the job had been completed, equipment performance issued began to occur. “This was despite the fact that these systems were part of regular PM and PdM checks,” Hachey notes. “The two most frequent performance issues were nuisance tripping on variable speed drives and increased noise and temperature at specific transformers.”
The maintenance team began troubleshooting procedures to discover the root cause of the problems. “The team first ran a thermal imaging scan on the affected systems to see if there was an increase in temperature,” he says. “They noted a 10°C rise on Phase C of the lighting circuit panel, as well as a similar rise in temperature at the circuit’s transformer.” The next step was to identify the problem causing the temperature increases. Using a three-phase power quality analyzer, they were able to record a 12-per-cent phase unbalance between A, B and C phases. The imbalance was due to all new light fixtures being added to Phase C. “As there was ample capacity in this distribution panel, the fix in this case was simple,” Hachey says. “Redistribute the load to all three phases.” Next up was to find the source of the nuisance tripping. “The maintenance team realized the affected drive was connected to the same distribution panel as the recently modified lighting system,” he notes. “They again used their three-phase power quality analyzer to diagnose the problem.” They found high levels of fifth harmonic distortion and high levels of reactive power (decreasing the power factor level), and energy costs increased significantly on this circuit due to poor power quality.
“The nuisance tripping was caused by an under-voltage condition and was easily corrected by sequence adjustment among the machines in the circuit,” Hachey says. “The harmonics issue was solved by adding line reactors — and this also solved the overheating and noise problem at the trans former.”
3) Repeated motor failure on pump assembly
In this last example, a pump motor had failed four times over three years, causing not only increased energy consumption issues, but also the loss of thousands of dollars in production. Hachey explains how at this point, the maintenance manager decided to use a vibration tester to monitor the motor on a monthly basis.
“This strategy enabled the maintenance department to not only predict when the next failure would occur, but also identify the root cause of the problem,” he notes. “In this example, the issue was angular misalignment on the motor shaft.”
In addition to ending the cycle of premature motor failure, the alignment correction resulted in a decrease in power demand, as the motor no longer had to fight the added torque created by the alignment error.
By implementing conservation strategies so that synergies are maximized, and by continuing to improve upon testing and maintenance activities, significant savings can be achieved. If you have an unusual or significant energy-saving story, please let us know about it.
Treena Hein is a freelance writer based in Pembroke, Ont.
New features available in these distance meters:
• Integrated compass: provides a “heading” for distance measurement.
• Inclination sensor: assists with height tracking, leveling and indirect horizontal distance measurement when line of sight is blocked.
• Automatic endpiece correction: when measuring from an edge or corner, a built-in sensor detects the position of the bracket and automatically changes the reference point.
The rugged dust- and splash-proof distance meters allow for easy measurement of hard to access areas, like high ceilings, without climbing a ladder. The three models provide the right features and price points for a wide variety of applications:
〈 Fluke 414D
o Measures up to 50m (165 feet) with one button and an accuracy of +/- 2mm (0.079 in).
o Easy, automatic math for area and volume; add and subtract with ease.
〈 Fluke 419D
o Measures up to 80m (263 feet) with even greater accuracy of +/- 1mm.
o 3-line display plus storage for 20 complete displays.
o Tripod mountable.
〈 Fluke 424D
o Measures up to 100m (330 feet).
o Feature-rich meter includes tilt sensor for hard-to-reach measurements, corner angle feature, compass, and more.
The Fluke Distance Meters are available now at Canadian suggested list prices of $149 for model 414D, $299 for model 419D and $449 for model 424D.