Tag: clamp meter price philippines

Electrical Transmission Cables

As electricity is transmitted and distributed from generation plants to the end-users, it passes through numerous sections of low voltage (below 1000 V) and high voltage (defined in Singapore as more than 1000 V) cables.

In addition to these transmission cables, pilot cables (which consist of 5 pairs or 10 pairs of color-coded wires) are used to connect the secondary outputs of current transformers (CT) deployed at both ends of the transmission stations (also known as sub-stations).

To safeguard sensitive equipment and avoid the escalation of faults that may distress the entire transmission network, these pilot cables assist to detect any unbalances between the corresponding pairs of CT, which indicate fault conditions. Whereas only one pair of wire is required to complete the connections, operation, and redundancy planning call for a minimum of three functional pairs of wire at any one time.

It’s unbearable to have a single cable that spans the vast distance between sub-stations. The result comes numerous joints are formed to link different sections of cables together. Such joints are the weakest links in the system because they are imperiled to failures affected by environmental factors that include thermal stress and moisture absorption. The failures will highlight when current readings taken at the secondary of CT deviate from the proportional primary current readings.

During such failure is recounted, the utility’s maintenance team is entitled to repair the fault. They have to travel to the sub-station at one end to separate the affected CT and pilot cable at that sub-station. Then they need to travel to the sub-station at the other end to check the insulation resistance of the pilot cable. In this condition, the acceptable insulation resistance is 10 Mohms minimum with 500 V DC applied.

While they are at it, they will check the pair of wires that have been used, as well as all the remaining 4 or 9 pairs of wires in the same bunch of pilot cable, and ensure at least three pairs are functional. However, some wires may have permanent damage, there are prospects that different color wires are mixed in order to attain the minimum 3 functional pairs. As a result, the team must validate the exact inter-connect pairs and they term this work as “phasing”. This is done by examining the continuity of the respective wire pairs. When a joint is verified faulty, it will be cut out and a short jumper cable will be added and two new cable joints are formed.

Afterward, insulation resistance as well as “phasing” must be checked again to ensure no abnormality.

In addition to reported faults, the same tests can be assigned by a new extension of cables, or diversion of cables due to civil engineering works (ie. new housing project development). Time is a perilous consideration as the maintenance team is always hard-pressed to complete the troubleshooting and repairs in the shortest possible time. They find the Fluke 1587 Insulation Multimeter a very multipurpose tool as it can perform insulation resistance tests as well as voltage measurements and continuity checks.

Get to know more of the product Fluke 1587 https://presidium.ph/product/1587-insulation-multimeter/ or email us at info@presidium.ph

How To Measure Signals Using Test Probes

To measure ac or dc voltage:

  1. Turn the meter’s dial to the proper voltage function ().
  2. Link the black test lead to the COM terminal and the red test probe to the V terminal, specified by on the Fluke 381.
  3. Measure the voltage by moving the probes to the desired test points of the circuit.
  4. View the reading in the display.

To measure resistance or continuity:

  1. Turn the dial to.
  2. Remove power from the circuit being tested.
  3. Connect the black test probe to the COM terminal and
  4. The red test probe to terminal.
  5. Measure the resistance by moving the probes to the desired test points of the circuit.
  6. View the reading on the display.

If the resistance is < 30 Ω, continuity is indicated by a beeper continuously sounding. If the display reads OL, the circuit is open or the resistance being measured is greater than the meter’s resistance range.

To measure frequency (on the Fluke 381):

  1. Turn the dial to.
  2. Align to the center the jaw or flexible probe around the measurement source.
  3. Push the yellow shift button (‍on the Fluke 381) to shift to Hz.
  4. View the measurement in the display.

To measure capacitance (on Fluke 370 series clamp meters)

  1. Turn the dial to.
  2. Remove power from the circuit being tested.
  3. Connect the black test probe to the COM terminal and the red test probe to the terminal.
  4. Measure the resistance by touching the probes to the desired test points of the circuit.
  5. View the reading on the display.

Remember, the more you use, the more familiar you become in measuring signal using test probes. Visit our website at www.presidium.ph to know more about our products.

hot spot detection

Hot Spot Detection with Thermal Imaging

Obtaining the precise temperature measurements of electrical equipment with the use of thermal cameras can be difficult until you know exactly what you are looking for. Because most electrical components are made of bare metal, emissivity is low which can make the temperature measurement unreliable.

Emissivity is the ratio of how well materials radiate infrared energy. Its values fall between 0.0 and 1.0. When equipment measures 1.0 it is considered a perfect radiator. However, there are no perfect radiators, because the material is the basis of an object’s emissivity. The aim of why it is hard to use infrared technology to conduct quantitative inspections which requires accurate temperature measurements, this is why many prefer qualitative inspections, it focuses on the apparent temperature difference between comparable equipment under comparable loads or the same equipment under comparable loads.

Electrical anomalies can be detected easily if you know what you are looking for. Electrical circuits with current flowing through it produce heat. That’s why each time you inspect an electrical component it is hot. The thermal pattern plays an important role in detecting electrical system anomalies. The biggest part of abnormal heating in electrical systems is normally caused by abnormal electrical resistance on a contact surface. The improved resistance could come from Phase on phase short, winding to winding resistance imbalance, and Insulation breakdown.

The area of the highest thermal energy is at the connection point; the circuit gets colder when it is farther from the contact point. The greatest amount of heat is generated at the point of resistance and then it conducts away from its point of origin, which leads to a telltale pattern.

Interpreting emissivity in thermal images

The emissivity depends on the viewing angle, surface condition, spectral wavelength, and temperature. Almost all nonmetallic materials are efficient radiation of energy. Infrared cameras have the capacity to change the emissivity settings. The user of the camera can make adjustments to get closer to the surface temperature. Keep in mind, that if the emissivity is less than 0.60, you cannot obtain an accurate temperature reading; there are also other factors that can affect the temperature reading.

Inaccurate temperature can be a sign of trouble ahead. Prevent the danger from happening by checking equipment temperature meticulously. With Fluke thermal cameras you can detect issues before they become problems. Designed for everyday use, in the toughest industrial environments, Fluke offers infrared cameras for a wide range of applications. Reach us through info@presidium.ph for more information on thermal cameras or visit https://presidium.ph/product-category/products/fluke-industrial-group-tools/infrared-cameras/.

medial gas leak detection

Medical gas leaks in hospitals can affect a huge problem, especially for the maintenance teams. It is important to educate the team first on what to consider before testing medical gases and piping systems in the healthcare facility. You must consider the following factors in leak detection uses and restrictions of medical gases, risks associated with medical gases, and leak detection restrictions and options.

Uses and restrictions of medical gases

There are many variables that a hospital must consider inside their facility which includes healing patients, equipment, treatment, supplies, the safety of visitors, and their employees. But one of the most critical supplies that they need to manage is compressed medical gas which means they require a prescription for use and must be transported, stored, and dispensed under strict standards. Here are some examples of medical gases: Oxygen, Nitrogen, Nitrous Oxide, Carbon Dioxide, and Helium. These gases can be mixed individually together for patient diagnostics and to calibrate medical devices. In terms of restrictions, oxygen, and nitrous oxide are vaporous, it is essential to monitor the storage and distribution systems.

Risks associated with medical gas leaks

In transporting medical gases to healthcare facilities, it is a must to inspect the components for the leak, because exposure to medical gases can injure hospital staff. Exposure of gases comes from waste anesthetic gases. Leaks happen when the system is connected and disconnected. The volatility of these gases contains a potential fire hazard that can cause harm to healthcare workers. Also, the loss of pressure in the gas system can affect the quality of medical equipment. To prevent this from happening it is best to oversize a hospital’s air compressors.

Leak detection restrictions and options

Detecting leaks in compressed medical gas delivery is harder than finding leaks in normal compressed air systems, because of the nature of the gases and the challenging environment. One way to solve this problem is to spray approved leak detection liquid around the potential leak area and bubbles appear if there’s a leak. Another solution is the use of Fluke ii900 Sonic Industrial Imager; it lets you see leaks on an LCD screen from up to 50 meters away. It can be used to detect leaks in central air supply pipes and medical gas delivery systems because it is approved for use in areas where volatile gases like oxygen or nitrous oxide might be present.

 

To have an efficient gas leak detection it is very essential to educate yourself on what and what not to do before detecting the leak to prevent accidents from happening. Also, it is best if you have the proper tool that will efficiently help you detect the leak. Fluke ii900 Sonic Industrial Imager will help you detect the leak efficiently. Visit www.presidium.ph to learn more about our products. Contact us at +632 82515165 / +632 82570795.

controlling leakage

Importance of controlling leakage current

In any electrical installation, some current will flow through the protective ground conductor to ground. This situation is usually called leakage current. Leakage current mostly flows in the insulation surrounding conductors and in the filters protecting electronic equipment around at home or at the office. The problems occur when leakage current on circuits protected by GFCIs (Ground Fault Current Interrupters) causes unnecessary and irregular tripping. In most cases, it can cause a rise in voltage on accessible conductive parts.

Insulation has both electrical resistance and capacitance as it conducts current through both paths. Even with the high resistance of insulation, little current can actually leak. However, if the insulation is old or damaged, the resistance is lower and ample current may flow. Moreover, longer conductors with higher capacitance cause more leakage current. At GFCI breaker manufacturers, they recommend one-way feeder length to be limited to 250 feet (76.2 m), maximum.

On electric equipment, it contains filters intended to protect against voltage surges and other disruptions. These filters typically have capacitors on the input, which adds to the overall capacitance of the wiring system and the overall level of leakage current.

For more leakage current basics and its measurement and effects, head on to https://presidium.ph/ for the high-equipment insulation testers to prevent future leakage current. Get a quote now!

insulated tools

Why Insulated Tools are important

Safety is the utmost important reminder to anyone who works with or around electricity. It manages what you wear, how you work, and the tools you carry. And by tools, we mean all the tools you carry, not just battery-operated test tools. 91% of electrical workers approved that insulated hand tools are the most critical when working on electrical equipment. From electricians to utility workers and maintenance to HVAC technicians, they carry insulated hand tools such as screwdrivers, pliers, and cutters along with the best electrician tools.

When working around electricity, the thing to remember is to de-energize the equipment, however, that’s not the case. Sometimes nearby energized equipment has unknown energy pathways that might unexpectedly feed voltage into the equipment you’re working on.

Insulated hand tools safety

When hazardous and unpredictable situations occur, insulated tools provide an extra measure of protection against it. And high quality insulated hand tools are engineered to protect you from electric shock and reduce the possibility of arc faults caused by short circuits.

The NFPA 70E standard requires insulated tools to be used when working on or near electricity greater than 50 V as this will protect workers from possible injuries and avoid companies from paying fines and liability costs from accidents.

It is perilous to understand the difference between a regular hand tool and an insulated tool. With lots of hand tools containing rubber coating over plastic handles, it is far different from an insulated hand tool. High quality insulated hand tools are constructed of a special combination of materials that can block potentially hazardous voltages and protection against electric shock.

Insulated tool certification

In using insulated hand tools, one must be certified and must undergo stringent testing by third-party labs to prove that the protection works and the tools can withstand hard use, extreme temperatures, and even live flame. Importantly, they must also comply with international standards including IEC 60900 and ASTM F1505.

The level of protection that Fluke engineered for the new line of insulated tools goes beyond research. An application from the same stringent requires safety, reliability, and ergonomics to our insulated hand tools that we require of our handheld test and measurement tools. They are precision-engineered of CMV steel for superior durability and manufactured using the most advanced techniques in state-of-the-art facilities in Germany.

Safe and ergonomic

Fluke insulated hand tools are also designed to minimize wear and tear. They are ergonomically designed to adjust to your hand to diminish strain and weakness and help prevent repetitive motion injuries. Our insulated pliers and cutters give you more gripping strength and are slim enough to more easily access jammed junction boxes and panels.

When working with live equipment and not sure how much will protect you from your regular hand tools, get one now from Presidium’s Insulated Hand Tools. Visit https://presidium.ph/ for the high-quality insulated tools for easier work and for your protection.

true-rms-measurement

Do you know what is true-rms measurement?

How did you measure ac accurately before there were true-rms DMMs? There were three kinds of precision rms meters available to me. The available types were all analog; the electrodynamic, the iron vane, and the thermocouple. They were all fragile, requiring careful handling to achieve accurate measurements and avoid damage. They were also slow to respond and presented a significant load to the measured circuit.

How different it is today, with many digital multimeters featuring true-rms ac measurement capability. Today’s meters are rugged, respond quickly, are more sensitive, and present the results with easy to read, digital clarity. But there are some subtle points you should be aware of when making rms measurements.

Most DMMs today measure the ac-coupled true-rms signal, rejecting the dc component if any is present. A few models, such as the Fluke 189, offer the additional option of measuring ac+dc true-rms, calculating the total rms value with the dc component present. Why the difference? When should you use one versus the other?

In a properly operating power distribution system supplied through transformers, only ac should be present, so the ac-coupled measurement offered by most DMMs is appropriate. And, when a diode fails in a motor drive rectifier circuit, it’s usually more effective to detect the failure by observing a reading in the dc voltage function which rejects the ac component.

Then, there’s the case where you would like to trace an audio signal through an amplifier circuit. That signal might exist on the collector of a transistor where a dc bias current is also present. Here again, when you want to separate the ac and dc components, the ac-coupled mode of the DMM is the correct one to use.

One case for measuring ac+dc occurs in the output of unfiltered dc power supply where a significant ac ripple voltage is present on the dc signal. Since a resistive heater or incandescent lamp connected to such a supply will respond to the total energy available, an ac+dc measurement will more accurately indicate how the load might react.

What can you do if you have only the ac-coupled rms measurement capability in your DMM and you want to measure the combined ac and dc energy? Bring on the calculator.

You can first measure the ac voltage and then the dc, recording both values. Next, you square both terms and add these squared values together. Finally, you take the square root of the sum and you have the ac+dc true-rms value of the signal.

A variation of this technique may be used to investigate the ac output of an electronic motor drive by using the low pass filter function available on the Fluke 87V.

The primary signal of interest on the output of such a drive is the low-frequency signal that drives the motor. The low pass filter of the 87V isolates this signal so you can make accurate measurements of its frequency and true-rms voltage.

When you don’t use the filter, you get a much higher reading, because the measured signal now includes all the switching voltages used to create the motor drive voltage.

To determine the rms value of this difference, you can do the following:

  1. Measure the total voltage and record the value.
  2. Measure the voltage with the low pass filter on and record that value.
  3. Now, square both terms and subtract the second squared value from the first.
  4. Finally, take the square root of the result and you will have the true-rms value of all the excess energy that was not filtered, within the bandwidth of the meter’s input.

One case where rms results may be added or subtracted directly is at your household panel, where the sum of the two 120V legs is indeed 240V. Those two signals are coherent. Visit https://presidium.ph/ to get a compact true-rms meter for accurate electrical installation and troubleshooting.

waveform-on-an-oscilloscope

Common Waveform Variations on an Oscilloscope

Oscilloscopes track signals as they shift over time and indicate the signals on display. The amplitude of the signal is indicated on the vertical axis and time is shown on the horizontal. The device plots a graph of the instantaneous signal voltage as a function of time. In order to analyze waveform traces meticulously, here are the four characteristics of the waveform that you should look for amplitude, time, waveform shape and distortion, and waveform distances, specifically from the outside sources.

Here are the common variations to look for:

Symmetrical shape

Continuous waveforms should always be symmetrical. If there is an instance wherein you have to print traces and cut them into two pieces, both sides should be identical. A small difference can cause a problem. If the two components of the waveform are not symmetrical, there may be a problem in detecting the signal.

Rise and fall, edges

Specifically, with square waves and pulses, the rising or falling sides of a waveform can immensely impact the timing in the digital circuits. It may be essential to lessen the time per division to see the edge with greater resolution. The use of cursors and gridlines will help you measure the rise and fall times of leading and trailing edges of a waveform.

 Amplitude

Always double-check that the intensity of amplitude is within the circuit operating requirements. Test the constancy, from time to time. Meticulously track the waveform for a long period of time; also monitor changes in the amplitude. Use horizontal cursors to identify if there are any amplitude fluctuations.

 Noise or glitches

When waveforms are acquired through active devices such as transistors or switches, transients or other incongruities can have a result of timing errors, propagation delays, bad contacts, or another incident. Noise will overlay the acquired signal and it will be difficult to see the real data behind the noise. I can be generated externally from DC-DC converters, lighting systems, and high-energy electrical circuits.

Excessive ringing

Ringing can be visible most of the time in digital circuits and in radar and pulse-width-modulation applications. It occurs at the transformation from a rising or falling side to a flat dc point. Test for immoderate ringing, balance the time base to provide a clear illustration of the transition wave or pulse.

Momentary fluctuation

Momentary changes in the measured signal are usually the result of external causes such as sag in the main voltage, invigoration of a high – power device that is attached to the same electrical grid, or a loose connection. Use the ScopeMeter to watch the acquired waveform for a long period of time to depict the main cause of the problem.

Drift

Minor changes in a signal’s voltage over time can be difficult to detect. The change is slow that it is hard to distinguish. The changes and aging of temperature can impact passive electronic components which are resistors, crystal oscillators, and capacitors. The drift in a reference dc voltage supply or oscillator circuit is one of the main factors to diagnose.  Sometimes the only option is to track the calculated value (V dc, Hz, etc.) over an extended period of time.

 

In summary, it is necessary to practice good troubleshooting skills to save time and simplify the process of determining common waveform variation before the problem occurs. Try to discover more about troubleshooting methodology and make it a habit to always document key waveforms and measurements for future reference. Interested in getting an Oscilloscope? Get yours now at https://presidium.ph/?s=oscilloscopes

single-phase motor

Causes of Single-phase Motor Failures

The frequent failures with single-phase motors include a centrifugal switch, thermal switch, or the capacitor. Though these problems can be easily be addressed, it is essential that you check if the model you have is aged 10 years or less or more than 1 HP, and if not, then it’s time for an upgrade.

 

How to troubleshoot split-phase motors?

The split-phase motor has both starting and running winding. The starting winding is automatically removed by a centrifugal switch as the motor starts kicking though in usual cases, a thermal switch that has a manual and automatic reset is often used as it automatically turns off the motor when it starts overheating. The risk could be that the motors may restart at any time.

Troubleshooting procedures:

  1. Turn off the power and inspect the motor. Immediately change the motor if it is damaged or burned.
  2. Check if the thermal switch is at manual mode and if it is, restarts it and turn motor on.
  3. If the motor opts to start, use a voltmeter to check for voltage if it is within 10% of the listed voltage and other motor terminals. If it is incorrect, you must troubleshoot the circuit leading to the motor or if correct, simply turn motor off and test. We recommend you use our Fluke 87V Industrial Multimeter for full efficiency.
  4. Turn off the combination starter and lockout and tag starting mechanism per the company’s policy.
  5. With the power off, connect Fluke 87V to the same motor terminals the incoming power leads were disconnected from. The ohmmeter will then read determine the resistance of the starting and running windings. Since the windings are parallel, the combined resistance is less than the resistance of either winding alone. It is indicative that you immediately change the motor if it reads zero, then there’s a shortage or reads infinity, then an open circuit is present.
  6. Check the centrifugal switch for signs of burning or broken springs. If it has, changes the switch and if none, inspect it with an ohmmeter.

 

Troubleshooting capacitor motors

Troubleshooting capacitor is the same way as troubleshooting split-phase motors, only the additional device which is the capacitor has to be considered. A capacitor motor is a split-motor with another one or two capacitors. These capacitors give the motor more starting and running torque.

The common issue with capacitors is that it deteriorates fast. It has a limited life and without you knowing, it could already have a short circuit or an open circuit. So it is obvious that you will have to change it more often. You must be cautious that if these failures with capacitors are not immediately addressed, it may cause your motor to burn out or not start at all.

Capacitors are either oil or electrolytic and made with two conducting surfaces separated by a dielectric material. It is a medium to maintain an electric field with little to none outside energy supply. It is usually used to insulate the conducting surfaces of a capacitor.  Furthermore, an oil capacitor is sealed in a metal container and the oil serves as the dielectric material.

Between oil and electrolytic capacitors, electrolytic are more often used. It is formed by winding two sheets of aluminum foil separated by pieces of thin paper impregnated with an electrolyte. The electrolyte is used as the dielectric material as it acts as the conducting medium through a current flow by ion migration.

The aluminum foil and the electrolyte is sealed in a cardboard or aluminum cover but note that it must have a vent hole to prevent possible explosion if the capacitor is overheated or shorted.

Troubleshooting procedures:

  1. Turn off the combination starter and lockout and tag starting mechanism per the company’s policy.
  2. Measure voltage using Fluke 87V at the motor terminals to make sure the power is dead.
  3. Capacitors are found on the outside frame of the motor. Remove the cover but in this process, be cautious as the capacitor may hold charge though the power is off.
  4. Check for leakage, cracks, or bulges. Replace if found.
  5. Remove the capacitor from the circuit and discharge it. In order to safely discharge it, place a 20,000-ohm, 2 W resistor across the terminals for five seconds.
  6. After discharging, connect Fluke 87V leading to the capacitor terminals. The device will determine the condition of the terminal to be either good, shorted, or open.

 

Visit our website at www.presidium.ph to know more about our products.

electronics in your building

It may happen as a surprise for some that electronics-related problems in buildings are often rooted back to power problems.

 

Almost every major subsystem in today’s commercial buildings has some type of solid-state electronics installed. These include HVAC units with an electronics board in its control panel. Regardless of what system type it may be, their common denominator is electronics.

 

Another issue can occur due to old vs new electronics as some electronic equipment in buildings are installed 20 or more years ago, which can be more prone to issues over time. Being electronic systems, they are all susceptible to problems due to power even if some electronic manufacturers can claim an amount of tolerance to power problems to their products.

 

Typical power scenarios

 

Knowing these common scenarios can be valuable as these are repetitive and can sometimes even occur more frequently.

 

Lightning strike

 

A lightning strike is a common scenario but will obviously vary depending on your location and climate. Flashes of Lightning can cause a lot of problems, and because HVAC equipment and a lot of the building electronics are located on the roof or outside of the building, it is vulnerable to lightning strikes.

 

The effects of lightning strikes can be fatal as the electronics can be completely wiped out, with visible burn marks and a burned smell. A good way to prevent such an occurrence is to move the electronics and to install better lightning protection and grounding.

 

Power loss & Generation Testing

 

Power loss is another common problem and can be caused by a multitude of reasons such as utility problems, maintenance lapses, and device surges to name a few. Depending on the condition of power loss, there is a chance that the electronic device may not recover properly even when power is restored.

 

When power loss occurs, the backup generator will start after a short delay. Power surges may also occur along with voltage or current problems when generators start. This can cause electronic circuit problems. This is a common issue that electronic devices have a problem after the generator test is performed.

 

If a system is critical, a small UPS is installed at the electronic device power supply. This ensures that the device doesn’t meet a power failure and can offer some form of surge protection. Another tested technique is to reboot the device by removing power until it is completely shut down, before turning the power on again.

 

Utility Problems

 

The power utility is also one of the root causes of problems with electronic devices. The nature of these problems is more systemic, and ongoing which makes it harder to solve. In some cases, they can be unique as some utilities will not readily acknowledge power problems. If the problems are repetitive with no direct correlation to lightning strikes, the usual suspect is utility problems.

 

One of its main indicators is the location of the utility power feed as some utilities feed power to a building from a substation that is distant or has other big customers. Having more than one customer on the same power feed will manifest itself through power problems for the building. Often the buildings will have the same symptoms or power problems.

 

The best solution for utility problems is to install power quality measuring equipment to find out the problem and where it occurred. This can help in asking for an adjustment or reimbursement to the electronics.

 

Power problems are detrimental to electronic devices. The power supply of the building must be checked by a power technician to ensure that it is working properly. Untreated power problems can lead to the failure of these electronic devices which can affect operations of the building systems.

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